Logging invalid LSP packets received

1. Enter the configure terminal command to access global configuration mode.
   

   device# configure terminal

2. Enter the router isis command to enter IS-IS router configuration mode and enable IS-IS on the device.
   

   device(config)# router isis
   

3. Enter the log invalid-lsp-packets command to enable the logging of invalid LSP packets.
   

   device(config-isis-router)# log invalid-lsp-packets
   

The following example enables the logging of invalid LSP packets.

device# configure terminal
device(config)# router isis
device(config-isis-router)# log invalid-lsp-packets