Compaq TCPIP Services for OpenVMS Tuning and Troubleshooting

This document, "Compaq TCP/IP Services for OpenVMS Tuning and Troubleshooting" (January 2001), is a technical manual for experienced OpenVMS or UNIX system and network managers. It focuses on providing information to identify and resolve network problems and to tune the performance of Compaq TCP/IP Services for OpenVMS (Version 5.1 on OpenVMS Alpha/VAX 7.1/7.2).

The manual is divided into two main areas:

1. Troubleshooting Techniques and Tools: This section describes how to identify network problem symptoms (e.g., physical, transport, configuration errors) and systematically isolate their causes. It introduces and details various diagnostic tools, including ping for connectivity, ifconfig for network interface parameters, arp for IP-to-Ethernet translation tables, netstat for network statistics, TCPTRACE for monitoring traffic, nslookup and ndc for name server operation, route and traceroute for checking routes, and SHOW SERVICE for verifying network service availability.
2. Tuning Techniques: This section explains how to adjust TCP/IP kernel subsystem attributes to enhance network performance. It covers modifying parameters within socket and inet subsystems, such as increasing TCP connection limits, socket buffer sizes, TCP hash table sizes, and adjusting timeout and retransmission rates. It also provides guidance on tuning server applications (e.g., memory configuration, IP address logging) and offers specific performance recommendations for primary servers.

Appendices offer detailed references for the troubleshooting tools and a comparison of TCP/IP Services commands with commonly used UNIX commands.