Cisco Router 2911 has unknown protocol drops issue

Xiaojing Li · ‎03-11-2012

Hi all,

I have issues to connect Cisco 2911 to HP switch. I disable CDP on the LAN port, router at A end is ok, but the unknow protocal drops as same as before at B site. It happend around every 30sec. When I transfer a file from one end to the other end. It always disconnect every 25 second. HP Switch is not configure trunk as it work as a plain network

Any other issues is possible?

paolo bevilacqua · ‎03-12-2012

Unknow protocol drops normal. thye are the SPT packets from switch, and are not the cause of your problem.

Xiaojing Li · ‎03-12-2012

Hi Paolo,

Thanks for the reply, but my issue is package seems dropped when we try to transfer file from PC A to B. When we check router, only this error shows. And two site are using same switch and same config. Only Site B shows this error, site A is fine. Except this issue, is there any other things i should try to troubleshoot?

Thanks

paolo bevilacqua · ‎03-13-2012

Hi, recommend you engage a reputable consultant, or certified Cisco partner, or Cisco TAC to help you resolve this issue.

Otherwise you have to provide a lot more data / evinde tof the problem.