Troubleshooting Guide

General diagnostic tools
Virtual Services Platform 4000 has diagnostic features available with Enterprise Device Manager
(EDM) and Avaya command line interface (ACLI). You can use these diagnostic tools to help you
troubleshoot operational and configuration issues. You can perform such tasks as configuring and
displaying log files, viewing and monitoring port statistics, tracing a route, running loopback and ping
tests, and viewing the address resolution table.
For more information about statistics, see Performance Management of Avaya Virtual Services
Platform 4000 Series, NN46251-701.
Traceroute
Traceroute determines the path a packet takes to reach a destination by returning the sequence of
hops (IP addresses) the packet traverses.
According to RFC1393, traceroute operates by: "sending out a packet with a time-to-live (TTL) of 1.
The first hop then sends back an ICMP error message indicating that the packet could not be
forwarded because the TTL expired. The packet is then resent with a TTL of 2, and the second hop
returns the TTL expired. This process continues until the destination is reached. The purpose
behind this is to record the source of each ICMP TTL exceeded message to provide a trace of the
path the packet took to reach the destination."
Ping
Ping is a simple and useful diagnostic tool to determine reachability. When you use ping, the switch
sends an ICMP echo request to a destination IP address. If the destination receives the packet, it
responds with an ICMP echo response.
If a ping test is successful, the destination is alive and reachable. Even if a router is reachable, it
could have improperly working interfaces or corrupted routing tables.
Trace
Use trace commands to provide detailed data collection about software modules on Virtual Services
Platform 4000. The trace toolset can be used to trace multiple modules simultaneously and provides
options to specify the verbosity level of the output.
You can enable trace logging through the boot config trace-logging flag.
Caution:
Risk of traffic loss
Using the trace tool inappropriately can cause a CPU lockup conditions, loss of access to the
switch, loss of protocols, and service degradation.
While these occurrences are uncommon, when using the trace level tool, minimize this risk. Avaya
recommends:
• In situations where trace data is required concurrently from multiple modules, consider
troubleshooting during a maintenance window if feasible. Consider a maintenance window
period if the switch is stable but CPU utilization is high and CPU traces (example trace levels 9
and 11) are required to diagnose the cause.
• Run trace commands from the console port when the CPU utilization is already high. While you
can enable or disable tracing when directly connected to the console port.
Troubleshooting tool fundamentals
January 2017 Troubleshooting 34
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