Tracking the used ports on router

Answered Question
Sep 18th, 2007


We want to know which the the ports used by one edge location router ( one serial and one fasteth port only ), by monitering the serail port or by it's fasteth port. As it is a edge router any interface will give the same result as all default traffic is routed to serial interfaces. I have tried command to check cache entries

# sh ip cache flow

This command shows source , destination IP and ports , but there is some pre-requisite for this command to work. I didnt get what exactly is that pre-requisite. any link on or if any other way to find out ports those are used by applications at that location which cross router ?

Thanx in advance


I have this problem too.
0 votes
Correct Answer by Joseph W. Doherty about 9 years 1 month ago

Have you enabled flow cache on your interfaces?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (1 ratings)


This Discussion