Network administrators at times face the challenge of output drops which causes data traffic loss. Output drops are generally caused by congested interfaces and best possible option to address this situation is to look into increasing the speed of that link. Other factors may also be responsible for causing output drops on interfaces.
Some of common causes of output drops on interface are enlisted below –
- Bad cable
- Oversubscription on the port or module
- Speed/Duplex mismatch.
Sometime overall traffic utilization may be showing low, however traffic bursts under “show interface” may not be giving clear picture. The default output rate is 5 minutes which may miss the bursty traffic. One option is to shorten the load interval from the default 5 minutes to 30 seconds using the interface-level command of “load-interval 30”.
Some of other Troubleshooting methods include –
- Using wireshark for detailed understanding of output drops.
- Increasing queue-limit
- Increasing hold queue
Infact following list of command can be very useful in troubleshooting output drops on interface –
- show interfaces switching
- show interfaces stats
- ip accounting mac-address
- show interfaces mac-accountin
- sh int <int no> | include drop
Below is the output of “show interface” command to show output drops as under –