packet drop issue after unplugged Cisco C1000 with C1000 uplink cable

[anirbanshil.ars1]

Hi,

We have configured the trunk port Cisco C1000 switch with C1000 Switch. All is ok. 

But when we have unplugged the uplink cable after than upstream host machine drop the ICMP. 
We have checked the interface logging status by console cable, there have no interface down issue. Also check the interface status log, here is showing the multicast packet. 

Scenario:
Cisco router>>Cisco C1000 (SW-01)>> trunk port >>Cisco C1000 (SW-02)

Need your suggestion how it can be solved the issue. 

Regards,

Anirban Shil 

[Flavio Miranda]

@anirbanshil.ars1 

Sounds like spanning-tree doing his job.

 You can put the uplink as Port fast to avoid recalculation

[anirbanshil.ars1 · Accepted solution]

Thanks for your guideness. 
We have enabled the BPDUGuard on global setting after that issue has been resolved. 

[MHM Cisco World · Accepted solution]

Don't use portfast, it only for host/server not for SW-SW.

Share 

Show switchport interface x/x <<- from both SW

MHM

[Richard Burts]

Anirban Shi

We could provide better answers if we knew more about your situation. The OP seems to describe a router connecting to SW1 which has a trunk connecting to SW2. Is my understanding correct?

The OP also mentions a host. Where is that host?  And very importantly where is the gateway for that host? Are these switches operating as layer 2 switches or as layer 3 switches?

I am going to make a guess that the gateway for the host is the router. In that case when you unplug the uplink then the host can no longer reach its gateway.

[anirbanshil.ars1]

Thanks for your guideness. 
We have enabled the BPDUGuard on global setting after that issue has been resolved.