Troubleshooting Toolbox - Last Input/Output

The show interface command contains a lot of great information. One of the often overlooked pieces of output from this command is the last input/output field. You can use this field to determine if packets are flowing in both directions on an interface, and - if they are not - when the last packets were registered ingress and egress on the interface. The only caveat is that only process-switched packets will be registered by these counters.

Last input - Number of hours, minutes, and seconds since the last packet was successfully received by an interface and processed locally on the router.

Last output - Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.

output hang - Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long.

Note: When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.

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[beefheadb0y]

Awesome - so useful to be able to see when an interface was last up on a switch. Thanks man, great vid. Will be sure to check out your others.