Expand Configuration and Management Manual (G06.24+)

Troubleshooting
Expand Configuration and Management Manual—523347-008
21-33
Resolving Common Network Problems
Resolving Common Network Problems
This subsection shows you, through examples, how to solve several common network
problems. These problems include the following:
•
Slow Response Time
•
Network Congestion
•
Node Not Available
•
Path Down
•
Line(s) Down
•
Duplicate Node
Slow Response Time
Slow response time is indicated when network response is worse than expected
relative to normal day-to-day performance.
The following five steps should be taken when attempting to resolve problems of slow
response time between nodes in the network.
Step 1: PROBE between nodes
To send a probe between nodes, use the following Expand subsystem SCF command:
PROBE PROCESS $NCP, AT \system1, TO \system2
If the probe time is slower than expected, probe shorter sections of the path to locate
the bottleneck. Example 21-13 shows a probe sent between \TARHEEL and \CASG.
You can use the list of node names provided by the PROBE display to probe a shorter
route each time until the node responsible for the bottleneck is found.
Example 21-13. SCF PROBE Display
6-> probe process $ncp, at \tarheel, to \casg
EXPAND Probe PROCESS $NCP
NETPROBES AT \TARHEEL (016) TIME: 17 FEB 1997, 10:19:13
113 \CASG - \NCWIND - \NCCORP - \NCTERM - \MEMPHIS - * (0086)
Note. SCF probes are small packets with a higher priority than normal node messages. Only
one probe can be initiated on a particular node at one time.