ULTRIX Introduction to Networking and Distributed System Services

This document, titled "ULTRIX Introduction to Networking and Distributed System Services" (Order Number: AA-ME97B-TE, June 1990), is a technical guide published by Digital Equipment Corporation for its ULTRIX operating system (Version 4.0 or higher). It is intended for system and network administrators responsible for maintaining ULTRIX-based networks.

The manual provides an overview of three main areas:

1. Networking Concepts:

   • Internet Addresses: Explains the 32-bit address structure, network classes (A, B, C), and different notation methods.
   • Routing Decisions: Covers direct and indirect routing, the use of routing tables, and methods for adding routes using the /etc/routed daemon and /etc/route command.
   • Subnetworks and Netmasks: Details how subnetworks are defined and configured with netmasks.
   • Internet Protocol Broadcast Addresses: Describes their function and default format.

2. Distributed System Services:

   • Naming Services: Discusses the Berkeley Internet Name Domain (BIND)/Hesiod and Yellow Pages (YP) services for distributing network databases (e.g., passwd, hosts), and the role of /etc/svc.conf.
   • Time Services: Explains the Network Time Protocol (NTP) for accurate, wide-area time synchronization and the Time Synchronization Protocol (TSP) for local network time synchronization.
   • Authentication Services: Introduces Kerberos authentication, integrated with BIND/Hesiod, and discusses configurable security levels (BSD, UPGRADE, ENHANCED), emphasizing the need for time synchronization.

3. Managing a Network with SNMP:

   • Provides an overview of the Simple Network Management Protocol (SNMP) as an industry standard for TCP/IP network management.
   • Details the ULTRIX SNMP Agent (/etc/snmpd) and Extended SNMP Agent, their functions, and how they interact with a Network Management Station (NMS) to manage the Management Information Base (MIB).
   • Explains SNMP Communities for access authentication, configured via the /etc/snmpd.conf file.

The document also includes appendices that list and describe important local area network configuration files (e.g., .rhosts, /etc/hosts, /etc/rc.local) and useful network maintenance commands (arp, ifconfig, netstat, ping, ruptime).