Module 6 — Networking & Cluster Operations

Overview

This module covers OpenVMS networking fundamentals, including TCP/IP Services, DECnet basics, cluster membership, SYSMAN cluster operations, lock management, and shared file access behavior. You’ll learn how to inspect network configuration, diagnose connectivity issues, and understand how OpenVMS clusters coordinate resources.

Exam: Multiple‑Choice Questions

1. Which command displays the current TCP/IP network interfaces and their status?

SHOW NETWORK
TCPIP SHOW INTERFACE
SHOW DEVICE/NETWORK
NETSTAT/SHOW

2. Which utility is used to manage cluster‑wide parameters and operations?

SYSGEN
SYSMAN
AUTHORIZE
CLUSTER_CONFIG

3. Which command displays the current node’s cluster membership status?

SHOW CLUSTER
SHOW SYSTEM/CLUSTER
SHOW NODE
SHOW MEMBERSHIP

4. Which protocol is responsible for lock management in an OpenVMS cluster?

TCP/IP
DECnet
Distributed Lock Manager (DLM)
LAT

5. Which command displays active DECnet circuits?

NCP SHOW CIRCUIT
DECNET SHOW LINKS
NET SHOW DECNET
SHOW NETWORK/DECNET

Hands‑On Exercises

Exercise 1 — Inspect TCP/IP Configuration

Display network interfaces:
TCPIP SHOW INTERFACE
Display routing table:
TCPIP SHOW ROUTE
Display active services:
TCPIP SHOW SERVICE

Exercise 2 — Test Network Connectivity

Ping another node:
PING <hostname>
Test TCP port connectivity:
TCPIP TELNET <host> <port>
Resolve a hostname:
TCPIP NSLOOKUP <hostname>

Exercise 3 — Inspect Cluster Membership

Display cluster nodes:
SHOW CLUSTER
Display cluster state:
SHOW SYSTEM/CLUSTER
Identify:
- Node names
- Voting configuration
- Quorum status

Exercise 4 — Use SYSMAN for Cluster Operations

Enter SYSMAN:
RUN SYS$SYSTEM:SYSMAN
Set environment to cluster:
SET ENVIRONMENT/CLUSTER
Display cluster parameters:
DO SHOW PARAMETER
Exit SYSMAN:
EXIT

Exercise 5 — Inspect DECnet Configuration

Display DECnet circuits:
NCP SHOW CIRCUIT
Display DECnet executor status:
NCP SHOW EXECUTOR
Display known nodes:
NCP SHOW KNOWN NODES

Scenario‑Based Troubleshooting Challenges

Scenario 1 — Node Cannot Join Cluster

A node boots but fails to join the cluster.

Expected approach:

Check cluster interconnect
Check SHOW CLUSTER from another node
Verify voting/quorum
Check DECnet or TCP/IP cluster transport
Inspect error log

Scenario 2 — Network Latency Between Nodes

Users report slow access to shared files.

Expected approach:

Check network interface errors
Check DECnet circuit counters
Check TCP/IP retransmissions
Check DLM lock contention
Monitor disk I/O on shared volumes

Scenario 3 — DECnet Communication Failure

A node cannot communicate with DECnet peers.

Expected approach:

NCP SHOW EXECUTOR
NCP SHOW CIRCUIT
Check line state
Check address conflicts
Check routing

Answer Key

The answer key for this module is located at:
answers/module6-answers.md