An interface discard is where the device has decided to discard a packet for some reason. It could be a corrupt packet, the device is busy, buffer overflows, packet size issues, and several other things. Network Performance Monitor pulls the discard information reported within a device from the RFC1213:IfTable.
What causes interface discards Cisco?
A typical cause of discards is when the router needs to regain some buffer space. In the case of discards, the issue is almost always with the router that's reporting the discards (not witha a next hop device, bad cable, etc).
How do you troubleshoot interface discards?
Troubleshooting Discards
- Verify VLAN configurations on ports and switches experiencing the discards. It is important to make sure the port is in the correct mode (trunk or access). ...
- Check the Spanning-Tree Topology. ...
- Check the interface bandwidth to see if its possibly overbooked.
