Packet In/Out on Interface

[wajnee123]

How can I see packet in/out on any interface of router in real time?

Like Packet Source, Destination, Packet type as we see in any packet sniffer softwares.

I have 3660 Router with IOS Version 12.2(2)T

[lgijssel]

You can use "debug ip packet" for this. Beware, this type of debugging is very heavy on the router. You should preferrably use an access-list to limit the amount of debug output: deb ip pack

This debugging will only work when the packets are process-switched. To achieve this, disable fast switching by using the interface command: no ip route-cache. Do not forget to restore fast switching once you have finished debugging.

Regards,

Leo

[wajnee123]

Can I use ip accounting for this purpose?

[Kevin Dorrell]

IP accounting will only give you a total number of packets and octets between pairs of IP addresses, and optionally can also tell you whether they were dnied by an access list, or which interface they came in on.

It will not give you a realtime trace. That is what debug ip packet is for.

Kevin Dorrell

Luxembourg