Monitoring incoming/outgoing packets on a Cisco switch
debug packet interface gi0/1
http://www.cisco.com/en/US/docs/ios/12_2/debug/command/reference/dbfmodem.html#wp1060637
Important Note:
Because the debug packet command generates a substantial amount of output for every packet processed, use it only when traffic on the network is low, so other activity on the system is not adversely affected.
Related videos on Youtube
Steve Townsend
Systems Administrator, Consultant, Programmer, Linux geek, Computer geek, Networking geek. I work for Net Direct, Canada's leading Linux solutions provider and largest Canadian IBM System x VAR. LinkedIn Profile Achievements Unlocked
Updated on September 17, 2022Comments
-
Steve Townsend over 1 year
I would like to monitor (i.e. have the switch print out packets) incoming and/or outgoing packets on a Cisco switchport.
For instance, I'd like to be able to tell it:
Print to the log all packets arriving on Gi0/1
.Something tells me this should be easy, but I can't find any way to do so!
I am aware that I could set up a mirror port, however for this particular scenario that won't be useful.
-
Aaron almost 13 yearsAre you actually trying to get a copy of every single packet on the port? Mirror/SPAN/RSPAN is the "correct" answer - a debug will kill the CPU on the router.
-
Steve Townsend almost 13 yearsI don't even remember the original circumstances that led to me asking this question, but according to above I am aware I could set up a mirror port but it wouldn't be useful for that particular case.
-
Aaron almost 13 yearsOops, sorry, didn't realize how old this was. I guess I'm trying to understand the circumstances of "I want a copy of every packet" but "Span won't work".
-
Steve Townsend almost 13 yearsNo worries - it's actually good for site to get activity on old (especially unanswered) questions.
-
-
Steve Townsend over 13 yearsA good answer, but not supported on any of my hardware (C2960, C3012, CIGESM, 2621 router). Any info on which versions of IOS support
debug packet interface
?