Troubleshooting SC0 in Catalyst 6500 switch

[joseph.ng]

How can I troubleshoot management interface SC0 in the Catalyst 6500 ? I received some error messages reported by CiscoWork managemment that there was HighDiscardRate in Sc0. When I logged in to the switch, i could not find any error logging message in the sysloy buffer. Moreover, I can't find any more commands that can help me to troubleshoot this issue . Can someone help me how to find the root cause of this issue ?

[Prashanth Krishnappa]

Can you do "sh netstat interface" and see if you see any errors? If you are, check if there is lot of traffic coming into sc0. You could sniff this interface if needed.

[joseph.ng]

Thanks for your response. I have done the "show netstat interface"command in the switch and it seens like there are high traffic on the SC0 interface. I even sniff this vlan to our sniffer but I wouldn't find any abnormality in this interface. But when I use the sh netstat stat , it shows that there are no such port in udp stat and the value keeps on increasing. I may like to ask how to sniff this virtual port to the span port instead of using vlan to the span port .I have also attached the command result for your review and hope that from the attached doc you may help me to find the root cause.

[Prashanth Krishnappa]

No such ports indicate Number of UDP packets received destined for nonexistent ports.

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_7_6/cmd_ref/sh_ml_n.htm#wp1040770

You can do a "sh netstat" to see what ports the switch listens to.

You can sniff the sc0 in a 6500

6500> (enable) set span sc0 ?

Destination module and port numbers

6500> (enable) set span sc0

Check for a

[joseph.ng]

Thanks for your reply.

I have attached the output for the show netstat command. I hope you may help me to explain those output display to me . It looks like no issue to me . Am I right ?