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ULTRIX

Guide to the Yellow Pages Service

Order Number: AA-ME008-TE
June 1990

Product Version:

ULTRIX, Version 4.0 or higher

Yellow Pages is a distributed data lookup service for sharing information between systems on
a network. This guide describes the Yellow Pages service.

digital equipment corporation
maynard, massachusetts

Restricted Rights: Use, duplication, or disclosure by the U.S. Government is subject to restrictions as set forth in
subparagraph (c) (1) (ii) of the Rights in Technical Data and Computer Software clause of DFARS 252.227-7013.

The information in this document is subject to change without notice and should not be construed as a commitment
by Digital Equipment Corporation. Digital Equipment Corporation assumes no responsibility for any errors that may
appear in this document.
The software described in this document is furnished under a license and may be used or copied only in accordance
with the terms of such license.
No responsibility is assumed for the use or reliability of software on equipment that is not supplied by Digital or its
affiliated companies.

The following are trademarks of Digital Equipment Corporation:

IDIDDmD
CDA
DDIF
DDIS
DEC
DECnet
DECstation

DECUS
DECwindows
DTIF
MASSBUS
MicroVAX
Q-bus
ULTRIX
ULTRIX Mail Connection

ULTRIX Worksystem Software
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Ethernet is a registered trademark of Xerox Corporation.
Network File System and NFS are trademarks of Sun Microsystems, Inc.
UNIX is a registered trademark of AT&T in the USA and other countries.

Contents

About This Guide
Audience

vii

Organization

. . . ... .. . .. . . . ... . . ... . . . .. . . . . . . . . . . . . ... . . . . ... . . . .. . . .. . . .. . . .. .. . . .. . . . . .. . . . . . . . . .. . . . .. . . .. . . . .

Related Documents

...........................................................................................

vii
vii

Conventions

viii

New and Changed Information

viii

Introduction to the Yellow Pages Service

1.1

Overview of the Yellow Pages Service

1.2

How the YP Service Operates

1-2

1.2.1
1.2.2
1.2.3

1-2
1-2
1-3

Naming Domains ......................................................................... ..
Storing Data ................................................................................. .
Default YP Files ........................................................................... .
1.2.3.1
1.2.3.2
1.2.3.3

1.2.4

.... ...... .. . .. .... ..... .. .... . .... .. .. . .. .. . .. . .. . .... .

The /etc/h.osts File .............................................................. .
The /etc/passwd File ........................................................... .
Other YP Files ................................................................... .

1-1

1-3
1-4
1-4
1-4

The /etc/svc.conf File

Setting Up and Modifying Yellow Pages

2.1

Overview of Setting Up a YP Server and Client

2-1

2.2

Prerequisite Information

2-2

2.3

Setting Up YP Manually
2.3.1

......................................................................... ..

Setting Up a YP Master Server
2.3.1.1
2.3.1.2
2.3.1.3
2.3.1.4
2.3.1.5
2.3.1.6

2-2

....................................................... .

2-2

Establish the YP Domain .................................................... .
Build the Default YP Maps ................................................. .
Start the YP Server Daemons .............................................. ..
Modify the Default YP Files ................................................ .
Start the YP Password Server .............................................. .
Edit the /etc/rc.local File .................................................... ..

2-3
2-4
2-4
2-4
2-5
2-5

2.3.1.7
2.3.2

...........................................................

2-5

Edit the /etc/svc.conf File with svcsetup .................................
Editing the /etc/svc.conf File Manually ..................................

2-5
2-7

..........................................................

2-7

Establish the YP Domain .....................................................
Obtain Copies of the YP Maps ..............................................
Start the YP Server Daemons ................................................
Modify the Default YP Database Files ...................................
Edit the /etc/rc.local File ...... ................................. ...............
Modify the /etc/svc.conf File ...................... ...... ....................
Edit the /usr/lib/crontab File .................................................
Add the New Slave Server to the Domain . ............... ......... ......

2-8
2-8
2-8
2-8
2-8
2-9
2-9
2-9

Setting Up a YP Client
2.3.4.1
2.3.4.2
2.3.4.3
2.3.4.4
2.3.4.5

2.4

2-5

Setting Up a YP Slave Server
2.3.3.1
2.3.3.2
2.3.3.3
2.3.3.4
2.3.3.5
2.3.3.6
2.3.3.7
2.3.3.8

2.3.4

...................................................

Modify the /etc/svc.conf File
2.3.2.1
2.3.2.2

2.3.3

Create the YP Servers Map

...................................................................

2-9

Establish the YP Domain .....................................................
Start the YP Port Mapper Daemon .. ............. ........... ...... .........
Modify the Default YP Database Files ...................... .............
Edit the /etc/rc.local File ......................................................
Modify the /etc/svc.conf File ................................................

2-10
2-10
2-10
2-10
2-10

2.4.1
2.4.2
2.4.3
2.4.4
2.4.5
2.4.6

The networks, protocols, rpc, services, and netgroup Files .................. .
The /etc/hosts.equiv File ................................................................ .
The /.rhosts File ........................................................................... .
The /etc/hosts File ........................................................................ .
The /etc/passwd File ..................................................................... .
Reducing the /etc/group File to a Single Line .................................. ..

2-13

.............................................................................. .

2-14

Using make to Propagate YP Maps ................................................ ..
Using makedbm to Propagate YP Maps ........................................... .
Using ypxfr to Propagate YP Maps ................................................ ..

2-14
2-15
2-15

Modifying and Creating YP Maps

2.6

Propagating YP Maps
2.6.1
2.6.2
2.6.3

2-11
2-11
2-11
2-12
2-12
2-13

............................................................. .

2.5

2.6.3.1
2.6.3.2
2.7

2-10

Altering YP Client Local Files

Running ypxfr from cron
Running ypxfr Manually

Modifying the YP Environment

2-16

2.7.1
2.7.2
2.7.3
2.7.4

2-16
2-17
2-17
2-18

Adding YP Servers to the Domain ................................................. ..
Removing YP Slave Servers from the Domain ................................. ..
Changing a YP Map's Master Server .............................................. ..
Adding Users to a YP Client ......................................................... ..
2.7.4.1
2.7.4.2
2.7.4.3

;vContents

Edit the YP Master Server's /etc/passwd File ........................ ..
Update the YP Map ............................................................ .
Make a Home Directory ...................................................... .

2-18
2-19
2-19

2.7.4.4
2.7.4.5

Set Up the New User's Environment ......................................
Propagate the Updated YP Map ............................................

Maintaining and Managing the Yellow Pages Service

3.1

System Security with YP
3.1.1
3.1.2
3.1.3

..........................................................................

3-1

Using the -S Option .......................................................................
Global and Local YP Files ..............................................................
Local System Files with Pointers to YP Maps ...................................

3-1
3-1
3-2

3.2

YP Map Access Policies

3.3

Special YP Password Change

3.4

Using Netgroups

Troubleshooting the Yellow Pages Service

4.1

How to Solve Problems on a YP Client
4.1.1
4.1.2
4.1.3
4.1.4

4.2

2-20
2-20

...........................................................................
....................................................................

3-3
3-4
3-4

.......................................................

4-1

Solving the Problem of Commands That Hang ................................ ..
Problems Caused by YP Service Unavailablity ................................ ..
Determining why the ypbind Process Exits ...................................... ..
Why the ypwhich Command Might Be Inconsistent .......................... .

4-1
4-3
4-4
4-4

How to Solve Problems on a YP Server

4-4

4.2.1
4.2.2

4-6
4-6

Updating a YP Database ................................................................ .
Determining Why the ypserv Process Exits ...................................... .

Appendix

Contents v

About This Guide

Yellow Pages is a distributed data lookup service for sharing infonnation between
systems on a network. This guide describes the YeHow Pages service.
The objective of this guide is to provide introductory, setup, and troubleshooting
infonnation for the Yellow Pages Service (YP). This guide will assist you in
developing YP management procedures and presents guidelines from which you can
develop specific procedures for your site.

Audience
This guide is meant for the person responsible for maintaining networks on an
ULTRIX operating system. This person is usually the system manager, but could be
a network manager or the system manager who is also a user of a Micro VAX
processor. This guide assumes that the reader is familiar with the ULTRIX system
commands, the system configuration, the naming conventions, and an editor such as
vi or ed. It assumes that the reader knows the names and addresses of the other
systems on the network.

Organization
This guide consists of four chapters, an appendix, and an index. The chapters are:
Chapter 1

Introduces YP and provides the background information needed before
you can set up and run YP on your system.

Chapter 2

Describes how to manually set up YP on your system. The
description is included for those who want to understand how YP
operates and which files are affected by YP.

Chapter 3

Describes how to maintain and manage the YP service. System
security and YP map access policies are discussed.

Chapter 4

Describes the basic approach to solving YP-related problems. It
discusses various system problems you may encounter and explains
how to solve them. In addition, this chapter lists the YP error
messages and suggested solutions.

Appendix A

Lists and describes common commands.

Related Documents
You should have available the related hardware documentation for your system. You
should also have the ULTRIX documentation set, including the ULTRIX Reference
Pages.

Conventions
The following conventions are used in this guide:

The default user prompt is your system name followed by a right
angle bracket. In this manual, a percent sign ( % ) is used to
represent this prompt.

A number sign is the default superuser prompt.

user input

This bold typeface is used in interactive examples to indicate
typed user input.

system output This typeface is used in interactive examples to indicate system
output and also in code examples and other screen displays. In
text, this typeface is used to indicate the exact name of a
command, option, partition, pathname, directory, or file.

UPPERCASE
lowercase

The ULTRIX system differentiates between lowercase and
uppercase characters. Literal strings that appear in text,
examples, syntax descriptions, and function definitions must be
typed exactly as shown.

rlogin

In syntax descriptions and function definitions, this typeface is
used to indicate terms that you must type exactly as shown.

[ ]

In syntax descriptions and function definitions, brackets indicate
items that are optional.

{I}

In syntax descriptions and function definitions, braces enclose
lists from which one item must be chosen. Vertical bars are used
to separate items.
In syntax descriptions and function definitions, a horizontal
ellipsis indicates that the preceding item can be repeated one or
more times.

cat(l)

Cross-references to the ULTRIX Reference Pages include the
appropriate section number in parentheses. For example, a
reference to cat(l) indicates that you can find the material on the
ca t command in Section 1 of the reference pages.

New and Changed Information
This guide is a revision. New and changed information includes the following:
•

The file, / etc/ svc. conf now performs many of the actions formerly done
by the file, / etc/ svcorder. References to this change appear throughout
this guide.

•

A new option, -8, is available with the ypbind command with the entries for
/etc/ypbind and /etc/portmap in the /etc/rc .local file. This
option provides increased security.

viii About This Guide

Introduction to the Yellow Pages Service

This chapter introduces the network database service called Yellow Pages (YP) and
discusses the following topics:

1.1

•

Overview of the Yellow Pages service

•

How the YP service operates

Overview of the Yellow Pages Service
The Yellow Pages Service is a distributed database lookup service for sharing
infonnation between systems on a network.
Infonnation distributed by YP is stored in sets of a database files called maps. A
named set of YP maps is known as a domain. A domain is a distinct network
namespace and describes an area under the administrative control of YP. You can
think of a YP domain as a set of systems that share the same set of files, the YP
maps. A YP domain is different from an Internet or sendmail domain.
YP is based on a client/server model. Unlike other client/server relationships, such as
NFS, YP clients and servers are not machines, but are processes. YP domains are
organized into a master server, one or more slave servers, and numerous clients. The
master server is the only one whose database can be modified. Server databases are
automatically updated to keep their infonnation consistent with the master database.
Each domain can have only one master server. A YP server holds all the maps of a
YP domain in a subdirectory of / et c / yp which is named after the domain. For
example, if the name of the domain is market, maps for the market domain are in
/ etc/yp/market. You can detennine your YP domain by executing the
domainname command.
Note

The / etc/yp directory is symbolically linked to the /var /yp
directory.
Each system on the network belongs to a default domain detennined by an entry in
the / etc/ rc. local file at boot time with the domainname command.
The YP maps contain the infonnation that YP serves, and each map contains a set of
keys and associated values. For example, the host s map contains all host names on
a network as keys and the corresponding Internet addresses as values. Each YP map
has a map name, used by programs to access data in the map.
Programs must know the fonnat of the data in the map. Most maps are derived from
ASCII files such as /etc/passwd, /etc/group, /etc/hosts, and
/ etc/networks. Maps are implemented by dbm files located in the
/var /yp/ domainname directory on the YP servers. See dbm(3x) in the ULTRIX
Reference Pages for more infonnation.

Sometimes YP clients are served by YP servers on the same system, and other times
by YP servers running on a different system. If a remote system running a YP server
process exits, client processes can obtain the YP service from another system. This
feature makes the YP service almost always available.
In the YP environment, only a few systems have a set of YP databases. YP makes
the database set available over the network. A YP client system runs YP processes
and requests data from databases on other systems. Two kinds of systems have
databases: a YP slave server and a YP master server. For any map, one YP server is
designated the master, and all changes to the YP map should be made on that system.
The changes then propagate from master to slaves.
YP clients do not need to know the location of data, or how it is stored. Instead,
they use a network protocol to communicate with a database server that knows those
details.

1.2 How the VP Service Operates
The YP service provides a way for a network manager to maintain consistency
among selected system administrative files on all the systems in a YP domain.
The YP service maintains network-wide databases, such as / etc/hosts. The
servers throughout the network contain copies of the YP maps.
When any system on the network wants to look up something in / etc/hosts, it
makes a remote procedure call (RPC) to one of the servers to get the infonnation.
One server is the master - the only server whose database may be modified. The
other servers are slaves, and they are periodically updated so that their information is
synchronized with that of the master server.
YP can serve any number of files, including some that reside in the / etc directory,
such as /ete/passwd and jete/networks. In addition to these, users can add
their own files to YP.
The / ete/ sve. eonf file defines the order in which to query the name services
running on your system. It is a mandatory system file that is created when you install
the ULTRIX software.
The following sections describe various aspects of how YP accomplishes its services.

1.2.1

Naming Domains
A domain is a collection of systems that shares a set of YP maps and shares the same
YP master server. The domainname command tells you the name of the system's
domain. The getdomainname system call returns the name of the domain to the
program that called it.
Data is stored in the /var /yp/ domainname directory. A system can contain data
for several different domains. Recall that the / et e / yp directory is symbolically
linked to /var /yp.

1.2.2

Storing Data
YP maps store data in dbm files. For example, the YP map for / et c/host s in the
domain market might be stored in these files:

1-2 Introduction to the Yellow Pages Service

/var/yp/market/hosts.byaddr.dir
/var/yp/market/hosts.byaddr.pag
/var/yp/market/hosts.byname.dir
/var/yp/market/hosts.byname.pag
The makedbm command takes an ASCII file such as jete/hosts and converts it
into dbm files suitable for use by YP. However, system administrators should use
the Makefile script in the /var /yp directory to create YP map files. The
Makefile script then calls makedbm. See ypmake(8yp) in the ULTRIX
Reference Pages for further information on rebuilding YP databases.

1.2.3

Default YP Files
YP serves the following default database files:

•
•
•
•
•
•
•
•

jete/hosts
/ete/passwd
jete/group
jete/networks
/ete/rpe
/ete/serviees
/ete/protoeols
/ete/netgroup

Library routines such as getpwent, getgrent, and gethostent work with YP
according to how the / ete/ sve. eonf file has been set up. C programs that call
these library routines will need to be relinked to function correctly.
Note
If YP is running, the library routines such as getpwent, getgrent,

and gethostent, cause entries served by YP to to be returned in the
order the data appears in the YP map. This returned order is not
necessarily the same as the original ASCII files. See the yp _next
function described in ypelnt(3yp) in the ULTRIX Reference Pages for
further information.
The following sections discuss each of the default files.

1.2.3.1

The letclhosts File - The / etc/hosts file is stored as two different files in YP.
The first, hosts .byname, is indexed by host name. The second,
hosts .byaddr, is indexed by Internet address. The hosts YP map expands into
the four YP map files, with the suffixes .pag and .dir.
When a user program calls the library routine gethostbyname, a single RPC call
to a server retrieves the entry from the hosts. byname file. Similarly,
gethostbyaddr retrieves the entry from the hosts. byaddr file. If YP is not
running (which you can cause by commenting out the ypbind entry in the
/ ete/ re .loeal file), then gethostbyname reads the / etc/hosts file.
Maps sometimes have more than one name. Although the ypeat command is a
general YP map print program, it knows about the standard files in YP. Thus, the

Introduction to the Yellow Pages Service 1-3

command ypcat hosts is translated into ypcat hosts. byaddr, because
there is no file called hosts in YP. Type the following command for a list of
expanded names:
# ypcat -x

1.2.3.2

The letc/passwd File - The / etc/passwd file is similar to the / etc/hosts
file. It exists as two separate files, passwd.byname and passwd.byuid. The
ypcat program prints it, and ypmake updates it. Unlike the gethostbyaddr
and the gethostbyname library functions, however, the getpwent function reads
the local /etc/passwd file and interprets the YP special characters: plus (+),
minus (-), and at (@).
A plus (+) entry is used to include the entries from the YP pas swd map. A minus
(-) entry, on the other hand, is used to prevent this user from logging in to the
system regardless of the YP passwd map. Use the (@) character in conjunction
with plus and minus entries to either include or exclude members of the network
group specified. See netgroups(5yp) in the ULTRIX Reference Pages for further
information.
If you wrote a program using getpwent to print all the entries from your password
file, it would print a virtual password file. Rather than printing + and -, it would
print whatever entries the local password file included from the YP map.
If you are running YP and need to change a password, you must change the password
in the YP map using the yppasswd command, unless you need to modify an entry
in the local /etc/passwd file. The yppasswd command has the same user
interface as the pas swd command, but works only if the yppas swdd daemon is
running on the YP master server.

Note
The pas swd command does not change the password YP map. It
changes only the local password file /etc/passwd and not the YP
master password file on the YP master server that is usually stored as
/var /yp/ src/passwd. See Chapter 3 for further information.

1.2.3.3

Other YP Files - Of the other files used by YP in the / etc directory,
/ etc/ group is treated like / etc/passwd, in that the getgrent library routine
only consults the YP group map if explicitly told to do so by plus (+) or minus (-)
entries in the /etc/group file. The files /etc/networks, /etc/rpc,
/ etc/ services, / etc/protocols, and / etc/netgroup are treated like
/ etc/hosts: for these files, the library routines go directly to YP, without
consulting the local files.
Any plus or minus (+,-) entries have no effect in the /etc/networks,
/etc/hosts, /etc/rpc,/etc/protocols, /etc/services,and
/ etc/netgroup files.

1.2.4 The /etc/svc.conf File
The / etc/ svc. conf file defines the order in which to query the name services
running on your system. It is a mandatory system file that is created when you
install the ULTRIX software. If you want to use YP, you must edit the
/ etc/ svc. conf file with the necessary database and service order information.

1-4 Introduction to the Yellow Pages Service

The following is a typical entry in the / etc/ svc. conf file:
passwd=local,bind

This entry tells the system to search first locally for password information. If it
cannot find the information locally, the system then queries a YP server.
Note
It is recommended that you list lac a 1 as the first service for all

databases to increase speed and efficiency.
You can specify any of the following databases in the / etc/ svc. conf file:

•
•

aliases

•

group

•
•
•

hosts

•
•
•
•

passwd

auth

netgroup
networks
protocols
rpc
services

See Chapter 2 for information on editing / etc/ svc. conf and see svc. conf(5)
in the ULTRIX Reference Pages.

Introduction to the Yellow Pages Service 1-5

Setting Up and Modifying Yellow Pages

This chapter explains how to set up the Yellow Pages (YP) service on your system
YP manually and how to modify an existing YP environment.
This chapter discusses the following topics:
•

Overview of setting up a YP server and client

•

Prerequisite information for setting up a YP server or client

•

Setting up YP manually

•

Altering YP client files

•

Creating and modifying YP maps

•

Propagating YP maps

For information on setting up the Yellow Pages service automatically by using the
ypsetup command, see the Guide to System and Network Setup.

2.1

Overview of Setting Up a YP Server and Client
To set up a system as a server, the system must contain the YP maps and must also
run the YP daemons /etc/portmap and /usr/etc/ypserv. The YP master
server also must run the /usr/etc/rpc.yppasswdd daemon. The ypsetup
command places an entry in the / etc / r c . 10 cal file to start these daemons
automatically at boot time.
Any system, including a YP server, can act as a YP client by running the
/ etc/ypbind daemon. A YP client gets its information from a YP server if the
information is not in the client's local files. If a YP client cannot find the
information in its local files, it makes an RPC call to a YP server and gets the
information from a YP map.
The ypbind daemon remembers the name of the YP server. When a client boots,
ypbind broadcasts a request to the Ethernet wire asking for the name of a YP
server.
Similarly, ypbind broadcasts a request for the name of a new YP server if the old
server has gone off the network for any reason. If ypbind is run with the -S
security option, no requests are broadcast. Only directed requests to the specified list
of servers are issued. The ypwhich command gives the name of the server that the
ypbind daemon currently points to.
Users on a YP client can use the ypcat and ypmatch commands to print data from
a YP map. The following command prints the information in the YP hosts map:
# ypcat hosts

Similarly, the following command prints the information in the YP passwd map:
# ypcat passwd

To look for someone's password entry, you need to use either the ypcat or the
ypma t ch command. For example, to obtain the password entry for a user named
jane, use one of the following command lines:
# ypcat passwd I grep jane
# ypmatch jane passwd

2.2 Prerequisite Information
Before you can set up YP on your system, your system must be in multiuser mode
with the / u s r file system mounted, and your system must be established on a local
area network. In addition, you must know the answers to the following questions:
•

What is the default YP domain name for your system?

•

Will your system be the YP master server on the domain?
If your system will be the master server:

You must be sure there is no other master already existing on the domain.
You must know the names of the YP slave servers on your domain. To
keep the YP maps consistent across all YP servers, the YP master server
maintains a list of slave servers to send the updated copies of the maps
using the yppush command. The ypset up command adds the names
you enter to the master server's list.
•

Will your system be a YP slave server?
If your system will be a YP slave server, be sure there is a YP master server
already on the domain. Otherwise, you will not be able to initialize the YP
maps for your system.

•

Will your system be a YP client?
You must be sure there is at least one other system on the network configured
as either a YP master or slave server. Otherwise, you will not be able to access
the YP maps.

Once you have the required information, you are ready to set up the YP service.

2.3 Setting Up YP Manually
For an interactive setup with default answers, follow the automatic YP setup
procedure.
This section describes how to set up your system manually as a YP master server,
slave server, or client and helps you to understand how YP works.
Both the client and the server must be connected to an Internet network for YP to be
able to run.

2.3.1

Setting Up a YP Master Server
The following files must contain the data that will be served to the YP clients on the
domain:

2-2 Setting Up and Modifying Yellow Pages

•

/etc/group

•
•

/etc/hosts

•
•

/etc/passwd

•

/etc/rpc

•
•

/etc/services

/etc/networks
/etc/protocols

/etc/netgroup

If any of these files are not up to date, edit them and add the correct entries. For
example, the / etc/passwd file must contain an entry for each user on the domain
that the YP master server will serve.

In addition, be sure the / etc/ netgroup file is complete. If you do not have an
/ etc/netgroup file, create an empty one by typing the following command:
# cp /dev/null /etc/netgroup

See netgroup(5yp) in the ULTRIX Reference Pages for further infonnation.
By default, the YP maps for the YP master server are constructed from the files
residing in the / etc directory. If you want to modify the / etc files to contain only
the local entries for the master server, create a directory such as /var /yp/ src.
Then copy the master copies of the files to it. You should make all future
modifications there.
If you plan to run make, ensure that the netgroup file is in / etc. If it is not in

/ etc, the make command will not find the netgroup file.
For further infonnation, see make(l) in the ULTRIX Reference Pages.
To set up your system manually as a YP master server, follow these steps:
1.

Establish the YP domain

Build the default YP maps

Start the YP server daemons

Modify the default YP files

Start the YP password server

Edit the / etc/ rc. local file

Modify the / etc/ svc. conf file

Create the YP servers map

The following sections describe these steps.

2.3.1.1

Establish the YP Domain - Set the domain name and create the domain directory.
In the following example, the domain name is set to market:
yprnaster# /bin/domainname market
yprnaster# mkdir /var/yp/market

Setting Up and Modifying Yellow Pages 2-3

2.3.1.2

Build the Default VP Maps - Build the default YP maps:
ypmaster# cd /var/yp
ypmaster# make NOPUSH="Y"

2.3.1.3

Start the VP Server Daemons - If the RPC port mapper is not running, start it:
ypmaster# /etc/portmap

After you have started the RPC port mapper, or if the port mapper is already running,
start the ypserv daemon:
ypmaster# /usr/etc/ypserv

2.3.1.4

Modify the Default VP Files - If your system will be acting as a YP client in
addition to being a YP master server, create a directory such as /var /yp/ src.
Then, copy the default files to that directory (/etc/group), /etc/hosts,
/ete/netgroup, jete/networks, /ete/passwd, jete/protocols,
/ete/rpe, and jete/services). Edit the original default files in jete as
described in Section 2.5.
If you change the directory for all the default files, edit the Makefile script and
modify the DI R argument so that it specifies the new directory. For example, if the
original directory was / ete and the new directory is /var /yp/ sre, here is the
new argument to the Makefile script:
DIR=/var/yp/src

If you change the directory for some of the default files, but not all of them, edit only
the Makefile DIR arguments for those particular files.
If you change the directory for the password file, in addition to editing the
Makefile script, be sure to edit the /etc/re .loeal file to reflect the new
directory. For example, if the new directory for / etc/passwd is /var /yp/ src,
be sure the following entry is in the / ete/ rc .local file:
/usr/etc/rpc.yppasswdd /var/yp/src/passwd \
-m passwd DIR=/var/yp/src

Note
If you want to modify the YP master files at any time after changing a
directory for a default file, modify the files in the directory you created to
store YP files, such as /var /yp/ src. Then, run the makedbm
command. The files in / etc are the YP master server's local files and
do not contain entries for the YP clients on the domain.

Start the ypbind daemon:
ypmaster# /etc/ypbind [-8 domainname,serverl, ... ,server4]

Note that you can specify a maximum of four servers with this command and that the
servers must be listed in the /etc/hosts file.
For more information on using the -S option, see Chapter 3.

2-4 Setting Up and Modifying Yellow Pages

2.3.1.5

Start the VP Password Server - To allow YP clients to change their YP
password entries, start the YP password server daemon. For example, if the master
version of the passwd file is stored as /var /yp/ src/passwd, type the
following command:
ypmaster# lusr/etc/rpc.yppasswdd Ivar/yp/src/passwd \
-m passwd DIR=/var/yp/src &

2.3.1.6

Edit the /etc/rc.local File - Add an entry to the / etc/ rc .local file to set up
the default YP domp-in name, using this format:
Ibinl domainname domainname

You also need to add entries for the / etc/portmap, /usr / etc/ypserv,
/usr / etc/ rpc. yppasswdd, and / etc/ypbind daemons. For example, the
entry for ypserv should look like this:
if [ -f letc/portmap -a -f lusr/etc/ypserv ]; then
lusr/etc/ypserv; echo -n ' ypserv'
>/dev/console
fi

On subsequent reboots, the YP service automatically starts from the
/ et c / rc . local file.

Note
The order in which the entries appear in the / etc/ rc .local file
determines the order in which the services are started when the system is
brought to multiuser mode. Be sure that all YP entries precede any NFS
daemons or other service daemons, such as lpd for the printer service in
this file. Also, be sure that the entry for the domain name precedes the
entries for the YP daemons.

2.3.1.7

Create the VP Servers Map - Use the makedbm command to create the YP
servers map. For example, if the domain name is market and the YP slave servers
for the domain are osprey and nuthatch, type the following commands:
ypmaster# cd /var/yp
ypmaster# makedbm - market/ypservers
opsprey
nuthatch
<CTRL/O>

2.3.2

Modify the /etc/svc.conf File
You need to modify the / etc/ svc. conf file. The / etc/ svc. conf file
controls the order in which database services, such as YP, are used.

2.3.2.1

Edit the /etc/svc.conf File with svcsetup - The svcsetup command allows
you to print and modify the database selections in the / etc/ svc. conf file on the
current system. You must modify this file when you are adding or removing a
naming service, such as Yellow Pages or BIND/Hesiod.
Run the secsetup command if you want to change the security parameters.
Changes take effect immediately.

Setting Up and Modifying Yellow Pages 2-5

To run the svcset up command, you must be logged on as superuser. Type the
following:
# svcsetup

The svcset up command then steps through the setup procedure in the following
manner:
1.

Displays a menu asking whether you want to modify the existing svc. conf
file, print the default settings to the screen, or exit the svcset up command.
Select the modify option.

Lists the database services that you can modify. Each database is assigned a
corresponding number by the system. Select the databases that you want to
modify by listing the number of each database, followed by a space.
For example, to modify the services that access the aliases and group
databases, respond to the prompt as follows:
Change Menu for the /etc/svc.conf file
=>
=>
=>
=>
=>
=>
=>
=>
=>
=>

aliases
auth
group
hosts
netgroup
networks
passwd
protocols
rpc
services

0
1
2
3
4

5
6
7
8
9

all of the above => 10
none of the above => 11
Enter your choice(s) : 0 2

Press the Return key when you are through listing the databases.
If you opt not to edit any databases, the svcsetup command exits.

Displays a menu of the possible combinations qf naming services that you can
run on your system, with a number corresponding to each combination.
local
yp
bind
local,yp
local,bind
yp,local
bind,local

=>
=>
=>
=>
=>
=>
=>

1
2
3
4

5
6
7

After the svcsetup command lists the recommended naming service
combinations, it prompts you to specify the naming service order you want for
each of the databases you are changing. Enter the number that corresponds to
the new naming service order that you want to run.
The current service order setting is displayed in brackets ([D.
For example, if you chose to modify the service order for the ali a s e sand
group databases, the svcsetup command prompts you in the following
manner:
Enter the naming service order for the "aliases" database [5]: 1

2-6 Setting Up and Modifying Yellow Pages

local
yp
bind
local,yp
local,bind
yp,local
bind,local

=>
=>
=>
=>
=>
=>
=>

1
2
3
4
5
6
7

Enter the naming service order for the "group" database [5]:
local
yp
bind
local,yp
local,bind
yp,local
bind, local

=>
=>
=>
=>
=>
=>
=>

1
2
3
4

5
6
7

The [5] indicates that the default entry in the svc . conf file for the
aliases and group databases is local, bind.
4.

Prints an informational message to the screen that it is updating the svc. conf
file, and exits.

Note
Resolving a name locally is always faster than using a name service.
Therefore, as you add name services, such as YP and BIND, to your
system, place the local service first in the svc. conf file.
Always have the local service selected for the passwd and hosts database.
Only local and bind are valid for the auth database and only yp is valid
for the net group database.

2.3.2.2

Editing the /etc/svc.conf File Manually - You must be logged onto your system
as superuser to edit the svc. conf file. Invoke an editor, and add or modify the
database entries. Each entry should be on a new line and of the following form:
database=service, service

Although white spaces are permitted after commas, and new lines, they are not
required, however.
See svc. conf(5) in the ULTRIX Reference Pages for further information.

2.3.3

Setting Up a VP Slave Server
The local area network must be established before you can set up your system as a
YP slave server. In particular, you must be able to copy files from the YP master
server to the slave server, using the rep command. There must also be a YP master
server on the network running the yp s e rv daemon for the domain.
To set up your system manually as a YP slave server, follow these steps:
1.

Establish the YP domain

Obtain copies of the YP maps

Setting Up and Modifying Yellow Pages 2-7

Start the YP server daemons

Modify the default YP database files

Edit the / etc/ rc .local file

Modify the / etc/ svc. conf file

Edit the /usr / lib/ crontab file

Add the new slave server to the domain

The following sections describe these steps.

2.3.3.1

Establish the YP Domain - Set the domain name and create the domain directory.
For example, if your domain name is market, type the following:
ypslave# /bin/domainname market
ypslave# mkdir /var/yp/market

2.3.3.2

Obtain Copies of the YP Maps - Run the YP transfer command, ypxfr, for
each YP map your system will serve. For example, to run ypx f r on a system with
a YP master called orville on a domain called market for the /etc/passwd
map, type the following:
ypslave# ypxfr -h orville -c -d market passwd.byname
ypslave# ypxfr -h orville -c -d market passwd.byuid

To find a list of the YP maps that your system can serve, look on the YP master in
the /var /yp/ domainname directory. For example: /var /yp/market.

2.3.3.3

Start the YP Server Daemons - If the RPC port mapper is not running, start it:
ypslave# /etc/portmap

After the RPC port mapper is running, start the ypserv daemon:
ypslave# /usr/etc/ypserv

2.3.3.4

Modify the Default YP Database Files - If your system will act as a client, in
addition to being a YP slave server, edit the default database files as described in
Section 2.5. Then, start the ypbind daemon:
ypslave# /etc/ypbind [-8 domainname, serverl ,... ,server4]

Whenever you start ypbind, you can use the -S option for added security.

2.3.3.5

Edit the /etc/rc.local File - Add an entry to the /etc/rc .local file to set up
the default YP domain name. For example, if the domain name is market, the
entry should look like this:
/bin/domainname market

You also need to add entries for the / etc/portmap, /usr / etc/ypserv, and
/ etc/ypbind daemons. For example, the / etc/portmap daemon has the
following entry:
if [ -f /etc/portmap ]; then
/etc/portmap; echo -n ' portmap'
fi

2-8 Setting Up and Modifying Yellow Pages

>/dev/console

The entry for the ypbind daemon should look like this:
if [ -f /etc/portrnap -a -f /etc/ypbind ); then
/ etc/ypbind [-8 domainname, server} ,... ,server4); \
echo -n ' ypbind'
>/dev/console
fi

On subsequent reboots, the YP service automatically starts from the
/ etc/ rc .local file.

Note
Be sure that the entry for the domain name precedes the entries for the
YP daemons in the / etc/ rc .local file.
If your system is also running the Network File System (NFS), be sure

the YP entries precede the NFS entries in the / etc/ rc .local file.

2.3.3.6

Modify the letc/svc.conf File - See Section 2.3.2.1 for information about the
/ etc/ svc. conf file.

2.3.3.7

Edit the lusr/lib/crontab File - To allow your YP slave server to receive updated
copies of the YP master server's YP maps, place ypxfr command entries in the
/usr / lib/ crontab file. For examples of crontab entries, look at these files:
/etc/yp/ypxfr_lperday
/etc/yp/ypxfr_2perday
/etc/yp/ypxfr_lperhour
See cron(8) and ypxfr(8yp) in the ULTRIX Reference Pages for further
information.

2.3.3.8

Add the New Slave Server to the Domain - To add the new slave server to the
domain, follow the directions in Section 2.7.1.

2.3.4

Setting Up a VP Client
The local area network must be established before you can set up your system as a
YP client. In addition, there must be a YP server on the network running the
yp s e rv daemon for the domain.
To set up your system manually as a YP client, follow these steps:
1.

Establish the YP domain

Start the YP port mapper daemon

Modify the default YP database files

Edit the / etc/ rc .local file

Modify the / etc/ svc. conf file

The following sections describe these steps.

Setting Up and Modifying Yellow Pages 2-9

2.3.4.1

Establish the YP Domain - Set the domain name with the domainname
command, using this format:
/bin/ dornainnarne domainname

For example, to set the domain name for the domain market, type the following:
ypclient# /bin/domainname market

2.3.4.2

Start the YP Port Mapper Daemon - If the RPC port mapper is not running, start
it:
ypclient# /etc/portmap

2.3.4.3

Modify the Default YP Database Files - Edit the default database files as
described in Section 2.3.3.4. Then, start the ypbind daemon:
ypclient# /etc/ypbind

As an alternative, you can issue the following command:
/ etc/ypbind [-8 domainname, serverl ,... ,server4]

Recall that the -S option is for security. For more information, see Chapter 3.

2.3.4.4

Edit the /etc/rc.local File - Add an entry to the I etcl rc .local file to set up
the default YP domain name, using this format:
/bin/ dornainname domainname

You also need to add entries for the letc/portmap and letc/ypbind daemons.
For example, the entry for ypbind should look like this:
if [ -f /etc/portrnap -a -f /etc/ypbind ]; then
/etc/ypbind [-8 domainname, serverl, ... ,server4]; \
echo -n ' ypbind'
>/dev/console
fi

On subsequent reboots, the YP service automatically starts from the
letc/rc .local file.

Note
Be sure that the entry for the domain name precedes the entries for the
YP daemons in the letc/rc .local file.
If your system is also running the Network File System (NFS), be sure
the YP entries precede the NFS entries in the letc/rc .local file.

2.3.4.5

Modify the /etc/svc.conf File - See Section 2.3.2.1 for information about the
I etcl svc. conf file.

2.4 Altering YP Client Local Files
All YP clients on the network should be updated to use the YP master's versions of
the YP maps, rather than their potentially out-of-date local files. This policy is
enforced by running a ypbind process on the client system (including systems that
might be running YP servers), and by modifying or eliminating the following files:

2-10 Setting Up and Modifying Yellow Pages

/etc/group, /etc/hosts, /etc/hosts.equiv,/etc/netgroup,
/etc/networks,/etc/passwd, /etc/protocols, /etc/rpc,
/etc/services, and / .rhosts. The following sections discuss how to treat
each of these files.

2.4.1

The networks, protocols, rpc, services, and netgroup Files
The following files are not needed on any YP client:

•

/etc/networks

•

/etc/protocols

•
•
•

/etc/rpc
/etc/services
/etc/netgroup

If you would prefer to keep them, you can leave them where they are or you can

move them to backup files. The following example shows how to move the
/ etc/networks file to / etc/networks. old:
# mv Jete/networks /ete/networks.old

2.4.2

The letc/hosts.equiv File
The YP service does not serve the / etc/hosts. equi v file. However, you can
add escape sequences to activate YP. This reduces problems with rlogin and rsh
that are sometimes caused by different / etc/host s . equi v files on two systems.
To let anyone log in to a system, you could edit / etc/hosts. equi v so that it
contains a single line with only the plus character (+) on it, which matches any host
name.
However, you can exercise more control over logins by using lines of the following
form:
+@trusted_group1
+@trusted group2
-@untrusted_group

Each of the names to the right of the at character (@) is assumed to be a network
group name, defined in the global network group YP map that YP serves. For
example, if two trusted groups are s t a f f and use r s, and an untrusted group is
guest, these are the appropriate / etc/hosts. equi v entries:
+@staff
+@users
-@guest

If no escape sequence is used, only the entries in / etc/hosts. equi v are used;
YP is not used.

2.4.3

The I.rhosts File
The YP service does not serve / . rhosts files. The format of the / . rhosts file
is identical to that of / etc/hosts. equi v. However, because the / . rhosts file
controls remote root access to the local system, you should restrict access to it.
Make the list of trusted hosts explicit or use the network group names.

Setting Up and Modifying Yellow Pages 2-11

2.4.4

The letclhosts File
The jete/hosts file must contain entries for the local host's name and the local
loopback name. Otherwise, the system could hang while coming up to multiuser
mode. The entries in the jete/hosts file are accessed at boot time when the YP
service is not yet available. After the system is running, and after the ypbind
process is up, the / etc/hosts file is not accessed.
The following example shows the hosts file for YP client orville:
127.0.0.1
192.9.1.87

2.4.5

localhost
orville

# John Q. Random

The letc/passwd File
The / ete/passwd file should contain entries for root and the primary users of the
system and an escape entry to force the use of YP.
A sample YP client's /ete/passwd file looks like:
root:6H2/WWVZnlFgM:0:1:Bossman with a C shell:/:/bin/csh
operator: :0:28:0perator:/opr:/opr/opser
daemon:*:l:l:Mr. Background:/:
sys:xzuEOV1LjYpJM:2:3:Mr. Kernel:/usr/sys:
bin:xcvjW4alfaUn:3:4:Mr. Binary:/bin:
uucp:Nologin:8:8:USENET New System:/usr/spool/netnews:

The last line is the escape entry that informs the library routines to use the YP
service rather than give up the search. Entries that exist in the local files, such as
/ ete/passwd, mask analogous entries in the YP maps. In addition, earlier entries
in the file mask later entries with the same user name or the same user identification
(UID).

Note
It is important that the +: entry always be last. Any entries in the
/etc/passwd file placed after the +: entry are ignored because the
library routines go directly to the YP map.
If you run the netsetup or uucpsetup commands after YP is
running, check the /etc/passwd file to be sure the +: entry is last.
If you want to run uuep throughout your YP domain, you must run
uucpset up on the YP master server and then remake the password
maps:

Run uuepsetup on the YP master server.

Edit the /etc/passwd file. If /etc/passwd is the YP password
map, place the +: entry at the end of the file. Otherwise, move the
entries that uucpsetup appended after the +: entry to the YP
password map (usually /var /yp/ src/passwd).

Make the YP password map:
# cd /var/yp
# make passwd

See Sections 2.6 and 2.7 for further information about modifying and
propagating YP maps.

2-12 Setting Up and Modifying Yellow Pages

2.4.6

Reducing the /etc/group File to a Single Line
You can reduce the / etc/ group file to a single line by using the following format:
+:

This line forces all translation of group names and group identifications to be made
by the YP service.

2.5 Modifying and Creating YP Maps
You should modify the YP maps that YP serves on the YP master server, which then
propagates copies of its modified databases to the YP slave servers. You can modify
the maps you expect to change most frequently, such as pas swd, by first editing the
ASCII file and then running make on /var /yp/Makefile.
For example, to add a YP user, follow these steps:
1.

Edit the YP master server's pas swd file and add an entry for the new user. If
you have chosen to move the default files, as noted in Section 2.3.1.4, edit the
/var /yp/ src/passwd file. Otherwise, edit the file / etc/passwd.

Type the following commands:
# cd /var/yp

# make passwd

Whether you use the Makefile command in /var /yp or some other procedure,
the goal is the same; a new pair of dbm files must be created in the domain directory
on the YP master server. For further information, see ypmake(8yp) in the ULTRIX
Reference Pages.
You can manually edit the following nonstandard YP maps:
•

Maps that are specific to the applications of a particular vendor or site

•

Maps that you expect to change rarely

•

Maps for which no ASCII form exists, such as maps that did not exist before
YP was set up.

Use the makedbm command with the -u option to disassemble the YP maps into a
form that can be modified using standard tools, such as awk, sed, or vi. Then,
build a new version of the YP maps using the makedbm command. You can do this
manually in two ways:
•

You can redirect rna k e dbm output to a temporary file that can be modified and
then piped back into makedbm.

•

You can operate on the makedbm output within a pipeline that feeds directly
into makedbm again. This is appropriate if you can update the disassembled
map by modifying it with awk or sed, or by appending to it with cat.

For example, suppose that you want to create a nonstandard YP map, called mymap,
and that you want it to consist of key-value pairs in which the keys are strings such
as aI, bl, cl, and so forth, and the values are ar, br, cr and so forth. There are two
procedures that you can follow when creating maps. In one, you use an existing
ASCII file as input; in the other, you use standard input.
•

If there is an existing ASCII file, you can create the YP map for it using the
makedbm command. For example, if the file is named
/var /yp/ src/mymap. asc and resides on the YP master server called

Setting Up and Modifying Yellow Pages 2-13

ypmaster for a domain called market, you can create the YP map by typing
the following commands:
# cd /var/yp/src
# /var/yp/makedbm mymap.asc .. /market/mymap

To update the YP map, remember to modify the ASCII file first. Modifications
made to the map, but not also made to the ASCII file would become lost. Make
the modification like this:
# cd /var/yp/src

# vi mymap.asc
# /var/yp/makedbm mymap.asc .. /market/mymap

•

If there is no original ASCII file, you can create the YP map by typing input
like the following. In this example, the default domain is market:
# cd /var/yp/market
# /var/yp/makedbm - mymap

a1 ar
b1 br
c1 cr
<CTRL/D>

If you need to modify that map, you can use makedbm to create a temporary
ASCII intermediate file, which you can edit using standard tools. For example:
# cd /var/yp/market
# /var/yp/makedbm -u mymap > mymap.tem

You can now edit mymap. temp so that it contains the correct information. To
create a new version of the YP map, type the following commands:
# /var/yp/makedbm mymap.temp mymap
# rm mymap. temp

Support on the YP slave servers for propagation of the new maps consists of
appropriate entries either in /usr/lib/crontab or in one of the ypxfr
shell scripts mentioned in Section 2.3.3.7. To get an initial copy of the map,
you can run ypxfr manually on each of the slave servers. The map must be
globally available before clients begin to access it. If the map is available from
some YP servers, but not all, you get unpredictable behavior from client
programs.
After you have modified the YP maps, you need to propagate them to the other
servers on the domain. See Section 2.6 for a description of how to propagate YP
maps.

2.6 Propagating YP Maps
To propagate a YP map is to move it from place to place, usually from the master
YP server to a slave. You can propagate YP maps from the master server to the
slave in three different ways, as described in the following sections.

2.6.1

Using make to Propagate YP Maps
You can propagate the default YP maps from the master YP server using the make
command, as described in Section 2.6.1. For example, to propagate the ho s t s file,
type the following:
ypmaster# cd /var/yp
ypmaster# make hosts

2-14 Setting Up and Modifying Yellow Pages

The Makefile script automatically runs the yppush command to push the YP
map from the YP master server to the slave servers on the domain. See
ypmake(8yp) in the ULTRIX Reference Pages for further information about how
make propagates the YP maps.
The yppush command uses the ypservers YP map to obtain a list of YP servers
in your domain. To each of the named YP servers, it sends a Transfer Map
request. The ypserv command forks a copy of ypxfr, by invoking it with the -c
option, passing the information it needs to identify the map, and calling back the
initiating yppush process with a summary status.

2.6.2

Using makedbm to Propagate YP Maps
You can propagate nondefault YP maps from the YP master server using makedbm
and then yppush, as described in Section 2.6.1 For example, to propagate a
nondefault YP map called sales. asc that resides in /var /yp/ src on the
domain market, type the following:
ypmaster# cd /var/yp/src
ypmaster# /var/yp/makedbm sales.asc .. /market/sales
ypmaster# yppush sales

The yppu s h command uses the yp serve r s YP map to obtain a list of YP servers
in your domain. To each of the named YP servers, it sends a Transfer Map
request. The ypserv command forks a copy of ypxfr, by invoking it with the -c
option, passing the information it needs to identify the map, and calling back the
initiating yppu s h process with a summary status.

2.6.3

Using ypxfr to Propagate YP Maps
After you have initialized a YP slave server, you can propagate the YP maps from
the YP master server by running the ypxfr command from cron or by running it
manually.

2.6.3.1

Running ypxfr from eron - Maps have differing rates of change; for instance, the
protocols YP map might not change for months at a time, but the passwd YP
map could change several times a day in a large organization. You can set up the
/usr / lib/ crontab file entries to run ypxfr periodically at a rate appropriate
for any map in your YP database. The ypx f r command contacts the master server
and transfers the map only if the master's copy is more recent than the local one.
To avoid needing a crontab entry for each map, you can group several maps with
approximately the same change characteristics together in a shell script, which can be
run from /usr / lib/ crontab. Suggested groupings, mnemonically named, are in
the /var /yp directory. The following files do daily YP map checks and/or updates:
ypxfr lperhour, ypxfr lperday, and ypxfr 2perday. (If you set up a
YP slave server with ypset~p, these entries are placed in /usr / lib/ crontab
automatically.) If the rates of change are inappropriate for your environment, you
can modify or replace these shell scripts.
Run these shell scripts on each YP slave server in the domain. Also, alter the exact
time of execution from one server to another to prevent the master from overloading.
If you want the map transferred from a particular server other than the master, you
can specify this using the - h option with the ypxfr command within the shell
script.

Setting Up and Modifying Yellow Pages 2-15

Finally, you can check and transfer maps that have unique change characteristics by
explicitly invoking ypxfr from within /usr / lib/ crontab. For example:
15 2

* * * /var/yp/ypxfr_1perday

In this example, /var/yp/ypxfr_lperday is a script.
See ypxfr(8yp) and cron(8) in the ULTRIX Reference Pages for further
information.

2.6.3.2

Running ypxfr Manually - You can run ypxfr manually as a command.
Typically, you do this only in exceptional situations, such as when setting up a
temporary YP server to create a test environment or when quickly trying to update an
out-of-date YP server's YP maps. For example, to propagate the group YP map,
type the following:
ypslave# /usr/etc/ypxfr group.byname
ypslave# /usr/etc/ypxfr group.bygid

Be sure you run ypxfr for each file making up the YP map.
Each of the ypxfr transfer attempts and results can be captured in a log file. If the
file /var /yp/ypxfr .log exists, then the results are appended to it. There is no
attempt to limit the log file length. To stop the information from accumulating in the
log file, remove /var /yp/ypxfr .log. See ypxfr(8yp) in the ULTRIX
Reference Pages for further information.

2.7 Modifying the YP Environment
This section describes how to modify the YP environment. The following topics are
discussed:

2.7.1

•

Adding YP servers to the domain

•

Removing YP slave servers from the domain

•

Changing a YP map's master server

•

Adding users to a YP client

Adding VP Servers to the Domain
To add a YP slave server to the domain, begin by modifying the maps on the YP
master server. If the new server is a host that has not been a YP server before, you
must add the host name to the ypservers map in the master YP server's default
domain. For example, the following sequence adds a server named osprey to
domain market:
ypmaster# cd /var/yp
ypmaster# (/var/yp/makedbrn -u market/ypservers
I/var/yp/makedbrn - trnprnap
ypmaster# rnv trnpmap.dir market/ypservers.dir
ypmaster# rnv trnpmap.pag market/ypservers.pag
ypmaster# yppush ypservers

2-16 Setting Up and Modifying Yellow Pages

echo osprey)\

Note

The second command in this example is on two lines. You can type
these lines as one long command even if the line wraps on your screen,
or you can use the backslash escape character (\), as shown. You cannot
type half the command (without the backslash), press the Return key, and
type the second half.
The new host address should also be in the hosts YP map. If it is not, add an entry
for this host to the YP master server's master hosts file and then run make. For
example, if the hosts file is stored as jete/hosts, these are the commands:
ypmaster# vi fete/hosts

ypmaster# cd /var/yp
ypmaster# make hosts

Set up the new YP slave server's databases by copying the files from the YP master
server. To do this, log in to the new YP slave and set up the YP environment as
described in the Guide to System and Network Setup for the automatic procedure and
Section 2.3.3 for the manual procedure.
After you have added a server to the domain, you need to propagate the YP maps
from the YP master server to the new slave. See Section 2.6 for a description of how
to propagate YP maps.

2.7.2

Removing VP Slave Servers from the Domain
To remove a YP slave server from the domain, begin by modifying the maps on the
YP master server. You need to remove the server's host name from the ypservers
map in the master YP server's default domain. For example, ,the following sequence
removes a server named osprey from domain market:
ypmaster# cd /var/yp
ypmaster# /var/yp/makedbm -u market/ypservers 1\
grep -v ospreyl/var/yp/makedbm - tmpmap
ypmaster# mv tmpmap.dir market/ypservers.dir
ypmaster# mv tmpmap.pag market/ypservers.pag
ypmaster# yppush ypservers

Note

2.7.3

Changing a VP Map's Master Server
To change a YP map's master server to a different system, first build the map at the
new master. Because the old YP master's name occurs as a key-value pair in the
existing map, it is not sufficient to use an existing copy at the new master server or to
send a copy there with ypxfr. The key must be reassociated with the new master's
name. If the map has an ASCII source file, the current version should be present at
the new master. Remake the YP map locally with the following sequence:

Setting Up and Modifying Yellow Pages 2-17

newmaster# cd /var/yp
newmaster# make salary.byhour

In this example, salary. byhour is the name of the YP map. The
/var /yp/Makefile file must be set up correctly for the make command to work.
If it is not, you should do it before doing anything else. In addition, go back to the
old master (if it is to remain a YP server) and edit /var /yp/Makefile so that the
salary. byhour map is no longer made there. To do this, comment out the
section that made the map salary. byhour in the old master server's
/var/yp/Makefile.

If the map only exists as a dbm file, you can re-create it on the new master by
disassembling an existing copy from any YP server and running the disassembled
version back through makedbm. For example:
newmaster# cd /var/yp
newmaster# ypcat -k salary.byhour 1\
/var/yp/makedbm - market/salary.byhour

After making the map on the new master, you need to send a new copy of the map to
the other YP slave servers. Do not use yppush, because the other slaves would try
to get new copies from the old master, rather than the new one.
A typical method is to become superuser on the old master server and type the
following:
oldmaster# /var/yp/ypxfr -h newmaster salary.byhour

Now that you have a new copy on the old master server, you can run yppush. The
remaining slave servers will attempt to get the current version of the map from the
old master server. When they do, they will get the new map, which names the new
master as the current master.

2.7.4

Adding Users to a VP Client
To add a user to a YP client on the network, add an entry to the YP master server's
password file and create a home directory on the new user's system as described in
the following steps:
1.

Edit the YP master server's / etc/passwd file

Update the YP map

Make a home directory

Set up the new user's environment

Propagate the updated YP map

The following sections describe these steps.

2.7.4.1

Edit the YP Master Server's letc/passwd File - On the YP master server, add a
new line to the master copy of the password file. If you are using the file
/etc/passwd as the master copy, use the vipw command. The vipw command
brings the password file into the vi editor and prevents anyone else from editing it
until you are done:
ypmaster# /etc/vipw

Otherwise, edit the master copy. For example:
# vi /var/yp/src/passwd

2-18 Setting Up and Modifying Yellow Pages

The pas swd file is a readable ASCII file with a one-line entry for each valid user on
the system. Here is a sample passwd entry for a user named Jane Doe:
doe:fnuTqqab.6yec:444:10:Jane Doe:/usr/staff/doe:/bin/csh

See the Guide to System Environment Setup for a description of how to edit the
passwd file to add a new user.
Note

The remote systems on the network recognize a user by the user
identification (UID) number. Therefore, it is important that each user
have the same UID on each of the systems on the network.

2.7.4.2

Update the YP Map - After you have updated the YP master server's password file
and created a password for the new user, be sure to update the YP map by running
/var /yp/make for / ete/passwd:
ypmaster# cd /var/yp
ypmaster# make passwd

You need to adjust the make command if the master copy of the passwd file is kept
somewhere other than jete. For example, if the passwd file is in /var /yp/ sre,
type the following:
ypmaster# cd /var/yp
ypmaster# make DIR=/var/yp/src passwd

2.7.4.3

Make a Home Directory - On the new user's system, create a home directory for
the new user. Use the same directory name that you specified in the YP master
server's / ete/passwd file. For example, if you are setting up a new user doe in
/usr / staff, use this sequence of commands:
ypclient# cd /usr/staff
ypclient# mkdir doe
ypclient# chown doe doe
ypclient# chgrp 10 doe

A common group identification number is 10. See group(5yp) in the ULTRIX
Reference Pages for further information.
If the YP map for the password file has not yet been updated on the system's YP
server, you get an error message when you attempt to run the ehown command. The
message has the following format:
unknown user id:

uurname

In that case, you can use the new user's UID number (from the /ete/passwd file
entry) instead of the login name to change the owner of the home directory. Here is
the format of the command:
chown userid# username

See the Guide to System Environment Setup for further information about setting up
new user accounts.

Setting Up and Modifying Yellow Pages 2-19

2.7.4.4

Set Up the New User's Environment - You can define new users' login
environments in several ways. For example, you might give new users a copy of
such files as .login and. eshre if they use the C shell (/bin/ esh) , or just
.profile if they use the Bourne shell (/bin/sh). Copies of the default
environment files are stored in the directory /usr / skel. See the Guide to System
Environment Setup and esh(1) and sh(1) in the ULTRIX Reference Pages for
further information about setting up a new user's environment.
If the new user is a member of any groups at your site, add the user's login name to

the jete/group file as necessary. Be sure to make the changes to the
jete/group and /ete/netgroup files on the YP master server if you are
running YP. See group(5yp) and groups(l) in the ULTRIX Reference Pages for
more information about user groups.

2.7.4.5

Propagate the Updated VP Map - After you have modified the YP maps to
include the new user, you need to propagate them to the other servers on the domain.
See Section 2.6 for a description of how to propagate YP maps.

2-20 Setting Up and Modifying Yellow Pages

Maintaining and Managing the Yellow Pages
Service

This chapter explains how to maintain and manage the Yellow Pages (YP) service.
There are many ways you can use the YP service on your system, and some are more
efficient than others for your particular YP domain. The information included in this
chapter will help you understand the implications of setting up YP in various
manners.
This chapter also discusses system security with YP and offers ways to increase this
security.

3.1

System Security with YP
This section describes the various aspects of system security while YP is running.
For further information about security, see yppasswd(lyp), hosts. equi v(5yp),
exports(5yp), passwd(5yp), group(5yp), netgroup(5yp), and
yppasswdd(8yp) in the ULTRIX Reference Pages.

3.1.1

Using the -S Option
To increase system security, you can use the -s option with the ypbind command
and with the entry for /etc/ypbind in the /etc/rc .local file.
This option locks the domain and servers list. You can specify a single domain and
up to four servers when you use this option. Once you use the - S option, the
machine on which you entered the command will not switch domains and will use
only the servers specified in the command. All specified servers must be listed in the
/ etc/host s file.
The following example shows use of the - S option:
/ etc/ypbind -s domainname, serverl, server2, serverJ, server4

3.1.2

Global and Local VP Files
Of the YP maps, the following are originally in the / et c directory before YP is set
up: /etc/group, /etc/hosts, /etc/networks, /etc/passwd,
/ etc/protocols, / etc/ rpc, and / etc/ services.
In addition, YP uses the /etc/netgroup file to create the netgroup YP map.
The YP maps are divided into local and global file types. The / etc/passwd and
/ etc/ group files are local files. They are first checked for on the local system,
and then any entries beginning with the YP special characters (+, -, @) are
interpreted as appropriate.
The remaining YP maps (hosts, netgroup, networks, protocols, rpc, and
services) are treated as global files only. The information in these maps is
network-wide data and is accessed only from YP. However, when booting, each

system needs an entry in / etc/hosts for itself.
In summary, if YP is running, local files are consulted first; global files are only
checked in the YP maps.

3.1.3

Local System Files with Pointers to VP Maps
The files / etc/hosts. equi v and / . rhosts are not in the YP database. Each
system has its own unique copy. However, you can place entries in your
/ etc/host s . equi v file that refer to YP. Consider the following sample line:
+@engineering

Because this entry begins with +@, it includes all members of engineering as it is
defined in the YP map netgroup. (The @ refers to members of the
/etc/netgroup file.) A line consisting only of + includes everyone in the
/ et c /host s . equi v file.
Conversely, an entry starting with -@ excludes everyone listed in that network group.
For example, the following entry excludes everyone listed within the network group
sales:
-@sales

To be able to log in to a remote system without having a password, you need to have
an entry for your local system name in the /etc/hosts. equiv file and an entry
for your login name in the / etc/passwd file (on the remote system). By having a
plus (+) entry in /etc/hosts. equiv, you effectively bypass this check, and
anyone with a login entry in the /etc/passwd file is allowed to log in to the
system over the network without restriction.
The / etc/pas swd and / etc/ group files can also have plus and minus (+,-)
entries. A line such as the following in the / etc/pas swd file pulls an entry for
doe from YP:
+doe::::John H. Doe:/usr2/doe:/bin/csh

The user and group identifications and the password are obtained from YP. The
description field, home directory, and default shell are obtained from the plus (+)
entry itself.
On the other hand, an /etc/passwd entry such as the following gets all of its
information from YP:
+doe:

Notice the differences in the following two entries:
+doe::1189:10:John H. Doe:/usr2/doe:/bin/csh
doe::1189:10:John H. Doe:/usr2/doe:/bin/csh

In the first of the two entries, the password field is obtained from YP. In the second
entry, user doe has no password. Also, if there is no entry for doe in YP, then the
effect of the first entry is as if no entry for doe were present at all.

3-2 Maintaining and Managing the Yellow Pages Service

Note
Do not put the following entry in the /etc/passwd file:
+: : 0: 0:: :

This entry would make every YP client on the network insecure. Each
user whose password data is obtained from the YP service rather than the
local / etc/passwd file would have root identification and
permissions.
Finally, an entry such as the following excludes the user doe from being allowed to
log in to the system:
-doe:

See Chapter 1 for further information about the plus and minus entries.

3.2 YP Map Access Policies
This section summarizes the policies used by the C-library routines when they access
the following files on a system running YP:
lete/group
Always consulted. If there are plus or minus (+,-) entries, the YP group map
is consulted; otherwise, YP is unused.

lete/hosts
Consulted only when booting (by the ifconfig command in the
/ etc/ rc .local file). After that, the YP hosts map is used.
lete/hosts.equiv
Always consulted, but not kept in the YP maps. If there are plus or minus
(+,-) entries whose arguments are network groups, the YP netgroup map is
consulted; otherwise, YP is unused.

lete/netgrou p
Never consulted. The / etc/netgroup file is used only for the construction
of the YP netgroup map. All data is taken from YP.

lete/networks
Never consulted. The data that was formerly read from this file now comes
from the YP networks map.

lete/passwd
Always consulted. If there are plus or minus (+,-) entries, the YP password
map is consulted; otherwise, YP is unused.

lete/protoeols
Never consulted. The data that was formerly read from this file now comes
from the YP protocols map.
I.rhosts
Always consulted, but not kept in the YP maps. If there are plus or minus
(+,-) entries whose arguments are network groups, the YP net group map is
consulted; otherwise, YP is unused.

lete/serviees
Never consulted. The data that was formerly read from this file now comes
from the YP services map.

Maintaining and Managing the Yellow Pages Service 3-3

/etc/svc.conf
Always consulted. This file specifies the order in which database lookup
services are to be queried.

3.3 Special YP Password Change
When you change your password with the passwd command, you change the entry
explicitly given in the local/etc/pas swd file. If your password is not given
explicitly, but is pulled in from YP with a plus (+) entry, then the passwd command
prints this error message:
Not in passwd file.

If you are running YP on your system, the special account password entries are

stored in / etc/passwd, but general user accounts are typically stored in
/var /yp/passwd. Therefore, to change the superuser root password you must
use the passwd command. To change a general user's password in YP, you must
use the yppas swd command.
To enable the yppasswd command, the system administrator must start the
yppas swdd daemon on the system serving as the master for the YP password file.
The following entry in the / etc/ rc .local file causes the yppasswdd daemon
to start automatically each time the system is booted:
/usr/etc/rpc.yppasswdd /etc/passwd -m passwd DIR=/etc

See yppasswdd(8yp) in the ULTRIX Reference Pages for further information.

3.4 Using Netgroups
Netgroups are network-wide groups of systems and users defined in the
/ et c / netgroup file on the master YP server. These groups can be used for
permission checking during remote mount, login, remote login, and remote shell
processes.
The master YP server can use /etc/netgroup to generate three YP maps in the
/var /yp/ domainname directory: netgroup, netgroup. byuser and
netgroup. byhost. The netgroup YP map contains the basic information in
/ etc/netgroup. The two other YP maps contain a more specific form of the
information to speed the lookup process of network groups.
Some programs that consult the YP maps are mountd, rlogin, and rsh. The
mountd program consults them for system classifications, if it encounters netgroup
names in the exports file. The rlogin and rsh programs consult the
net group map for both system and user classifications if they encounter netgroup
names in the hosts. equi v or / . rhosts file.
If you place your / etc/netgroup file in a source directory (such as
/var /yp/ src), when you execute the make command in the /var /yp directory,
the make command will not find the netgroup file. To correct this, update the
netgroup file in the source directory. Then copy it to / etc/netgroup before
executing the make command. For more information, see make(1) in the ULTRIX
Reference Pages.
For information on the / etc/netgroup file format, see netgroup(5yp) in the
ULTRIX Reference Pages. See the Guide to the Network File System for information
about the Network File System (NFS).

3-4 Maintaining and Managing the Yellow Pages Service

Here is a sample I etc/netgroup file for the domain market:
# Engineering: Everyone, but eric, has a system; he has no system.
# The system 'testing' is used by all of the hardware group.
#

engineering
hardware software
hardware
(mercury, alan, market) (venus, beth, market) (testing, -, market)
software
(earth, chris, market) (mars, deborah, market) (-, eric, market)

#
# Marketing: Time-sharing on star
#
marketing
(star,fran,market) (jupiter,greg,market)\
(jupiter,dan,market)

#
# Others
#

allusers
allhosts

(-"market)
(,-,market)

Based on this sample, the users would be classified into groups for the domain
market as follows:

Group

Users

hardware
software
engineering
marketing
allusers
allhosts

alan, beth
chris, deborah, eric
alan, beth, chris, deborah, eric
fran, greg, dan
every user in the passwd YP map
no users

Here is how the systems would be classified:

Group

Hosts

hardware
software
engineering
marketing
allusers
allhosts

mercury, venus, testing
earth, mars
mercury, venus, testing, earth, mars
star, jupiter
no hosts
all hosts in the hosts YP map

Maintaining and Managing the Yellow Pages Service 3-5

Troubleshooting the Yellow Pages Service

This chapter describes the most common causes of YP malfunctions and provides
some methods for solving the problems. The following topics are discussed:
•

How to solve problems on a YP client

•

How to solve problems on a YP server

The source of a YP problem usually lies in one of the following areas:
•

There are no YP servers on the domain running the yp s e rv daemon

•

The network or the YP server is overloaded

•

The YP client has not set the domain name properly for the system

•

The ypbind process is not running

•

The network is down

Before you can solve YP problems, you must be familiar with how YP operates and
you should be familiar with the following YP commands and daemons:
domainname,portmap, ypbind,ypcat, ypmake, ypmatch, yppassw dd,
yppoll, yppush, ypserv, ypsetup, ypwhich, and ypxfr. For additional
information, see Chapter 2.
When solving YP problems, keep in mind that there are three main points of failure:
the server, the client, or the network.

Note
The client and the server must be connected by a network for YP to be
able to run and serve databases properly.

4.1

How to Solve Problems on a YP Client
This section provides a description of common errors on a YP client and offers
solutions for these problems. The problems are:

4.1.1

•

Commands hang

•

The YP service is unavailable

•

The ypbind process exits

•

The ypwhich command is inconsistent

Solving the Problem of Commands That Hang
The most common problem on a YP client is for a command to hang and generate
console messages of this form:

yp: server not responding for domain <domainname>.

Still trying

This message indicates that ypbind on the local system is unable to communicate
with yp s e rv in the specified domain.
Commands may hang if systems that run ypserv are taken off the network for any
reason. This may also occur if the network or the YP server is so overloaded that
ypserv cannot get a response back to the local system's ypbind within the
timeout period.
Under these circumstances, the other YP clients on the network show the same or
similar problems. The condition is temporary in most cases. The messages usually
disappear when a YP server reboots and yp s e rv is running again, or when the load
decreases on the YP servers or the Ethernet.
However, in the following circumstances, the situation does not improve:
•

The YP client has not set, or has incorrectly set, the domain name on the
system. Clients must use a domain name that the YP servers know. Use the
domainname command to see the client domain name. Compare that with the
domain name set on the YP servers. The domain name should be set in the
/ etc/ rc .local file. For example, if the domain name is market, there
should be an entry in the / etc/ rc. local file similar to this:
/bin/domainname market

If /etc/rc .local fails to set, or incorrectly sets, the domainname, do the
following:
1.

Become superuser on the system in question.

Edit / etc/ rc. local to fix the domain name line with a proper
name. This assures the domain name will be correct every time the
system boots.

Set domain name manually, so it is fixed immediately. For example,
if the domain name is market, type the following command:
# domainname market

•

If your domain name is correct, make sure your local network has at least one
YP server. You can bind to a yp s e rv process only on your local network, not
on another accessible network. There must be at least one YP server for your
system's domain running on your local network. Two or more YP servers
improve availability and response characteristics for the YP service.

•

If your local network has a YP server, make sure it is running. Check other
systems on your local network. If several client systems have problems
simultaneously, suspect a server problem.

Find a client system that is operating normally and run the ypwhich
command. If ypwhich does not return an answer, terminate it and go to a
terminal on the YP server and type the following command:
# ps ax I grep yp

Look for ypserv and ypbind processes. Depending upon the results, take
one of the following actions:
If the ps command shows no ypserv process running, start one:
# /usr/etc/ypserv

4-2 Troubleshooting the Yellow Pages Service

If the ypserv daemon was running but the ypbind daemon is not, start
it by typing:
# / etc/ypbind [-8 domainname, server} ,... ,server4]

Then execute ypwhich on the YP server. If ypwhich still returns no answer,
ypserv has probably hung and should be restarted. Terminate the existing
ypserv, ypbind, and portmap processes and start them again. For
example, if the process IDs are 102, 121, and 156 type the following
commands:
#
#
#
#

kill -9 102 121 156
/etc/portmap
/usr/etc/ypserv
/etc/ypbind

Find the process ID numbers by using the ps command.

4.1.2

Problems Caused by YP Service Unavailablity
If other systems on the network appear to be running properly, but the YP service
becomes unavailable on your system, many different symptoms can appear, such as:

•

Some commands appear to operate correctly, while others terminate, printing an
error message about the unavailability of YP.

•

Some commands run inefficiently in a backup strategy particular to the program
involved.

•

Some commands or daemons exit with obscure messages or no message at all.
Messages such as the following may appear (in this example, the domain name
is market):
# ypcat passwd
ypcat: can't bind to YP server for domain <market>
Reason: can't communicate with ypbind.

# /var/yp/yppoll passwd.byname
RPC TIMEDOUT

If symptoms such as these occur, type the following while in a directory
containing files owned by many users, including users not in your system's
/etc/passwd file (such as /usr):
# ls -1

If the ls command reports file owners who are not in your system's / etc/passwd
file as numbers, rather than names, this is another indication that YP is not working.

These symptoms usually indicate that the ypbind process is not running. Run the
ps command with the a and X options to check whether a ypbind process is
running; If it is, kill ypbind and then restart it. If you do not find the ypbind
process, type the following to start it:
# / etc/ypbind [-8 domainname serverl, ... , server4]

Another possibility is that the / etc/ svc. conf file is incorrect. Be sure this file
has an entry for YP.

Troubleshooting the Yellow Pages Service 4-3

4.1.3

Determining why the ypbind Process Exits
If the ypbind process exits almost immediately each time it is started, you should
look for a problem in some other part of the system. Check for the presence of the
portmap daemon by typing the following commands:
# ps ax I qrep portmap

If you do not find it running, reboot the system.
If the portmap daemon does not stay up or acts unusual, look for more fundamental
problems.

You may be able to talk to the portmap daemon on your system from another
system on your network that is operating normally. From such a system, use the
rpcinfo command. For example, if your system is named spice and the system
that is operating normally is named sugar, type the following from sugar:
sugar# rpcinfo -p spice

If your portmap daemon is running properly, the output should look like:
program vers proto
100003
2
udp
100005
1
udp
100004
2
udp
100004
2
tcp
100004
udp
1
100004
1
tcp
100007
2
tcp
100007
udp
2
100007
1
tcp
100007
1
udp

port
2049
1025
1033
1024
1033
1024
1025
1045
1025
1045

nfs
mountd
ypserv
ypserv
ypserv
ypserv
ypbind
ypbind
ypbind
ypbind

The port numbers on your system may be different from those shown.
If the ypbind processes are not there, ypbind has been unable to register its
services. Reboot your system. If the ypbind processes are there and they change
each time you try to restart / etc/ypbind, then reboot the system, even if the
portmap daemon is running.

4.1.4

Why the ypwhich Command Might Be Inconsistent
If you use the ypwhich command several times at the same client system, the
answer you get back may vary because the YP server can change. The binding of a
YP client to a YP server can change over time on a busy network, or when the YP
servers are busy.

Whenever possible, the system stabilizes at a point where all clients get acceptable
response time from the YP servers. As long as your client system gets the YP
service, it does not matter where the service comes from. A YP server often gets its
own YP service from another YP server on the network.
If ypwhich returns "Domain domainname not bound", this is not necessarily a
problem. Try entering ypcat passwd and then type ypwhich.

4.2 How to Solve Problems on a YP Server
This section provides a description of common errors on a YP server and offers
solutions to these problems.

4-4 Troubleshooting the Yellow Pages Service

Because YP works by propagating maps among servers, you can sometimes find
different versions of a map on different servers on the network. If transient, this
version skew is normal. Otherwise, it is abnormal.
Most commonly, a normal update is prevented when a YP server or a network
gateway system between YP servers is down during a map transfer attempt. When
the YP servers and the network gateways between them are running, ypxfr should
succeed.

If a particular slave server has update problems, log in to that server and run ypxfr
interactively. If ypxfr fails, it prints an error message that will help you solve the
problem. If ypx f r succeeds, but you believe that it is failing at times, create a log
file to enable the logging of messages by typing the following commands:
# cd /var/yp
# touch ypxfr.loq

This saves all output from ypxfr. The output looks much like what ypxfr creates
when run interactively, but each line in the log file is timestamped.
You might see unexpected orderings in the timestamps. The timestamp tells you
when ypxfr began its work. If copies of ypxfr ran simultaneously, but their work
took different amounts of time, they might write their summary status line to the log
files in a different order.
Any pattern of intermittent failure shows in the log file. After you have fixed the
problem, tum off logging by removing the log file. If you forget to remove it, it
grows without limit.
While still logged in to the problem YP slave server, inspect /usr / lib/ erontab
and the ypxfr shell scripts it invokes. Typing mistakes in these files can cause
propagation problems. Failures to refer to a shell script within erontab or failures
to refer to a map within any shell script can also cause propagation problems.
Make sure that the YP slave server is in the ypservers map within the domain. If
it is not, it still works as a server, but yppush will not tell it when a new copy of a
map exists.

If the problem is not obvious, you can work around it while you debug by using the
rep or tftp command to copy the current version from any stable YP server. You
might not be able to do this as superuser, but you probably will be able to do it as
daemon. For example, type the following to transfer a map called bu s t e r:
# chmod qo+w /var/yp/market
# su daemon

$ rep ypmaster:/var/yp/market/buster.\* /var/yp/market
$ <CTRL/D>
# chown root /var/yp/market/buster.*
# chmod qo-w /var/yp/market

Notice that the asterisk (*) has been escaped with a backslash in the command line so
that it will be expanded on the YP master server, instead of locally. In addition,
notice that the map files should be owned by root, so you must change ownership of
them after the transfer. It is easiest if you can do the rep command as superuser.

Troubleshooting the Yellow Pages Service 4-5

Note
Because of architectural differences between V AX processors and other
types of processors, you may not be able to copy files from one
processor to another using the rcp command. The ypxfr command,
however, does resolve the byte ordering differences found in a
heterogeneous networking environment.

4.2.1

Updating a VP Database
If you change a database and then execute a make command, the database may not
get updated. If this happens, remove the file database.time from the directories
Ivar/yp and Ivar/ypldomainname.

For example, if the net group file of the domain market is changed and
successfully updated, the make command should respond with:
netgroup updated

If the rna k e command instead states that the netgroup is up to date, enter these
commands:
# cd /var/yp
# rm netqroup.time
# cd cadnetwork
# rm netqroup.time
# cd ..
# make netqroup

4.2.2

Determining Why the ypserv Process Exits
If the ypserv process exits almost immediately and will not stay up even when
repeatedly activated, the process of finding the problem is virtually identical to that
described in Section 4.1.3. Check for the portmap daemon:
# ps ax I qrep portmap

Reboot the server if you do not find it. However, if it is there, run the rpcinfo
command:
# /usr/etc/rpcinfo -p
program vers proto
100003
2
udp
100005
1
udp
100004
2
udp
100004
100004
100004
100007
100007
100007
100007

2
1
1
2
2
1
1

tcp
udp
tcp
tcp
udp
tcp
udp

port
2049
1025
1033
1024
1033
1024
1025
1045
1025
1045

nfs
mountd
ypserv

ypserv
ypserv
ypserv
ypbind
ypbind
ypbind
ypbind

The port numbers on your system may be different from those shown. If ypserv
processes are not there, ypserv has been unable to register its services. Reboot the
system. If the ypserv processes are there but they change each time you try to
restart /usr / etc/ypserv, reboot the system.

4-6 Troubleshooting the Yellow Pages Service

Appendix

This appendix provides a quick reference for common YP commands.
makedbm (8yp)
Builds a dbm file, which is a valid YP map. Databases not built from
/var /yp/Makefile can be built using makedbm. The makedbm
command also disassembles a map so that you can see the key-value pairs.
You can modify the disassembled form with standard tools (such as editors,
awk, grep, and cat). The disassembled map is in the form required for input
back into rna k e dbm.
ypbind (lyp)
Activates the Yellow Pages binder daemon. The process is activated at system
startup time from / etc / r c . 10 caL It runs on all machines using the YP
services, both servers and clients. A ypbind process associates the domain
name with the Internet address of the YP server and the port on that host at
which the ypserv process is listening for server requests. The -S option
allows the system administrator to lock ypbind to a particular domain and set
of servers.
ypcat (lyp)
Displays the contents of a YP map. You can use ypca t when it does not
matter which server's version you are seeing. If you need to see a particular
server's map, log in to that server (using rlogin, or the rsh command) and
use the makedbm command.
ypmake (8yp)
Rebuilds the YP database by using the make command. The make command
uses the /var /yp/Makefile file to build any YP maps that are outdated,
and then executes the yppush command to notify slave databases that a
change has occurred. The ypmake command should run only on a YP master
server machine.
ypmatch (lyp)
Prints the value for one or more specified keys in a YP map. You have no
control over which server's version of the map you are seeing.
yppoll(8yp)
Determines the order number and master server for a specified map.
yppush (8yp)
Copies a new version of a YP map from the master YP server to the slave YP
servers. This command is run on the master YP server by the ypmake
command.
ypserv (8yp)
Activates the YP database lookup server. The ypserv process must run on
each YP server.

ypsetup (8yp)
Sets up your system YP environment for the first time. The ypsetup
command initializes the default maps for a master YP server, transfers copies of
the master YP server maps for a slave YP server, and sets up the
/etc/rc .local file for the master, slaves, and clients on the domain.

ypwhich (lyp)
Tells you which YP server a system is using at the moment.

ypxfr(8yp)
Moves a YP map from one YP server to another, using YP itself as the
transport medium. It can be run interactively or periodically from
/ etc/ crontab. In addition, ypserv uses ypxfr as its transfer agent when
it is asked to transfer a map.

A-2 Appendix

Index

crontab file

makedbm command
defined, A-I

editing, 2-9

master server
See YP master server

D
dbm file
storing data, 1-2
domain

N
netgroup file
format, 3-5

See YP domain

YP and, 1-4, 3-4

domain name

YP client and, 2-11

setting, 4-2

netgroup.byhost, 3-4
netgroup.byuser, 3-4

netgroups
group file
editing for YP, 2-13
pulling entries from YP, 3-2

defined, 3-4
networks file
yP and, 1-4

YP and, 1-4

YP client and, 2-11

home directory
creating, 2-19
hosts file

passwd file
See also passwd.byname file
See also passwd.byuid file