Using Trace

Trace on a switch is equivalent to enabling debugging on a router. It is, however, a resource drain that can potentially crash a switch. In rare situations where syslog messages, protocol analyzers, and pursuing other avenues for potential explanation for the behavior have been exhausted, trace is used. Trace is a hidden command, and, therefore, care is required if it is going to be enabled. The following command shows trace configured for VLAN Trunking Protocol (VTP) at level 4. The higher the level, the more information will be displayed by the switch. The range of levels is from 0, disabled, to 15:

Switch1(enable)set trace vtp 4