Operation Manual

Verifying Network Service
Diagnosing Low-Level Network Problems
11-17
11
Diagnosing Low-Level Network
Problems
The DTX-NSM module helps you troubleshoot links and
diagnose network problems up through layer 3 of the OSI
(Open Systems Interconnect) 7-layer model. It can also
indicate problems at higher levels. Higher-level problems
are usually addressed by a network technician or
administrator using a network tester or analyzer.
Table 11-2 lists common causes of symptoms you can detect
with the DTX-NSM module.
-continued-
Table 11-2. Diagnosing Low-Level Network Problems
No ping response, limited responses, or ping times seem high
Note
To evaluate ping times, you should compare current results with results
taken when the network was operating normally.
• Wiring fault on the link.
• Device is turned off.
• For static IP address assignment, incorrect address or subnet mask in Setup.
• A network fault, condition (such as network congestion), or security setting is preventing the device from answering.
• Since ping requests are low-priority traffic, devices may not respond to all requests.