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ATM Switch Router Troubleshooting Guide
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Chapter 2 Troubleshooting Tools
Using Diagnostic Commands
For further information about show commands, refer to the ATM Switch Router Command Reference
publication for your specific software version.
debug Commands
The debug privileged EXEC commands provide a wealth of information about the traffic seen (or not
seen) on an interface, error messages generated by nodes on the network, protocol-specific diagnostic
packets and cells, and other useful troubleshooting data.
Caution Exercise care when using debug commands. Many of these commands are processor
intensive and can cause serious network problems (such as degraded performance or loss
of connectivity) if they are enabled on an already heavily loaded switch router. When you
finish using a debug command, remember to disable it with its specific no debug
command (or use the no debug all command to turn off all debugging).
Appendix A, “Debugging an ATM SwitchRouter,” provides an overview of debug commands including
how to use them when you are troubleshooting the ATM switch router.
In many situations, third-party diagnostic tools can be more useful and less intrusive than using debug
commands. For more information, see the “Third-Party Troubleshooting Tools” section on page 2-3.
ping Commands
To check host reachability and network connectivity, use the ping user EXEC or privileged EXEC
command. This command can be used to confirm basic network connectivity on IP networks.
For IP, the ping command sends Internet Control Message Protocol (ICMP) echo messages. If a station
receives an ICMP echo message, it sends an ICMP echo reply message back to the source.
Using the extended command mode of the ping command, you can specify the supported IP header
options, which allow the switch router to perform a more extensive range of test options. To enter ping
extended command mode, enter yes at the extended commands prompt of the ping command.
show startup-config Displays the switch router configuration stored in
nonvolatile RAM (NVRAM).
show flash Displays the layout and contents of Flash memory.
show buffers Displays statistics for the buffer pools on the switch router.
show memory Shows statistics about the switch router memory, including free pool
statistics.
show processes Displays information about the active processes on the switch router.
show stacks Displays information about the stack utilization of processes and
interrupt routines, and the reason for the last system reboot.
show version Displays the configuration of the system hardware, the software version,
the names and sources of configuration files, and the boot images.
Command Purpose
