Sudeen increase in ifInDiscards

gerheauserm · ‎08-07-2007

I am suddenly seeing a tremendous increase in ifInDiscards but seeign no errors reported via the "sh port" command on one of my 6513's. AM not seeing an increase in actual traffic as reported via snmp, but the ifInDiscards has jumped significantly. Any hints on what to look for?

sundar.palaniappan · ‎08-07-2007

This probably doesn't indicate a problem with the functioning of the switch. These are error-free frames discarded by the switch for one of the following reasons.

From CCO:

"IfInDiscards?This is a count of valid frames received, which are discarded by the forwarding process of the switch. This is the same counter as the In-Discard field in the output from the show Mac command. You see this when you receive traffic on a trunk for a specific VLAN while the switch does not have any other ports on that VLAN. You also see this counter increments when the destination address of the packet is learned on the port the packet is received on, or when a port is configured as a trunk and that trunk is blocking for VLANs'

HTH

Sundar

gerheauserm · ‎08-07-2007

I am currently pruning back the vlan on the trunks of the this switch to reduce spanning tree overhead. Should I also go to the far end switches and prune back those same vlan's to reduce or eliminate these errors?

sundar.palaniappan · ‎08-07-2007

That's worth a try. Try that and let us know the outcome.

HTH

Sundar

gerheauserm · ‎08-08-2007

Sundar, pruning back on the far end connections did the trick. thanks for your help and fast response.

sundar.palaniappan · ‎08-09-2007

Mark glad to know that my post helped solve your problem :-)