Unknown protocol drop

[Prasad V]

After upgrading IOS from

c2801-ipbase-mz.124-11.XJ4.bin to

c2801-ipbasek9-mz.124-24.T8. Unknown protocol drops increments continously in router both internal and external fastethernet interfaces.

internal is local lan. and external configured as BGP.

No cdp enable is mentioned in all the router interfaces as well switch interfaces too.

but still it appears the same.

[nkarpysh]

Hello Prasad,

In your new IOS unknwo protocol drops started to be visible in show commands due to the following enhancement:

CSCsh98950 Need to display unknown protocol drops IDB counters

That means that drops were actually occuring before but with new IOS you can see those under interface counters.

Those packets are related to unknown (or unconfigured) protocol received. Thus if you wnat to eliminate of those you need to sniff the traffic and see what is there (e.g. one side of the link has some protocol configured and other side is missing that protocol - those packets can be considered as unknown and dropped).

Hope this helps.

Niko