I have an issue with one interface on a Cisco 3750 switch that seems to be reporting abnormally high transmit discards - over 200k / 30 mins. The strange thing is that the counts are frequently exactly the same or increment by one and occasionally the count is exactly double:-
| 11-May-2011 | 06:30 AM | 0 errors | 0 discards | 0 errors | 214331 discards |
| 11-May-2011 | 07:00 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 07:30 AM | 0 errors | 0 discards | 0 errors | 214331 discards |
| 11-May-2011 | 08:00 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 08:30 AM | 0 errors | 0 discards | 0 errors | 428662 discards |
| 11-May-2011 | 09:00 AM | 0 errors | 0 discards | 0 errors | 428662 discards |
| 11-May-2011 | 09:30 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 10:00 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 10:30 AM | 0 errors | 0 discards | 0 errors | 214331 discards |
| 11-May-2011 | 11:00 AM | 0 errors | 0 discards | 0 errors | 428663 discards |
| 11-May-2011 | 11:30 AM | 0 errors | 0 discards | 0 errors | 214332 discards |
| 11-May-2011 | 12:00 PM | 0 errors | 0 discards | 0 errors | 214332 discards |
| 11-May-2011 | 06:30 AM | 0 errors | 0 discards | 0 errors | 214331 discards |
| 11-May-2011 | 07:00 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 07:30 AM | 0 errors | 0 discards | 0 errors | 214331 discards |
| 11-May-2011 | 08:00 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 08:30 AM | 0 errors | 0 discards | 0 errors | 428662 discards |
| 11-May-2011 | 09:00 AM | 0 errors | 0 discards | 0 errors | 428662 discards |
| 11-May-2011 | 09:30 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 10:00 AM | 0 errors | 0 discards | 0 errors | 0 discards |
| 11-May-2011 | 10:30 AM | 0 errors | 0 discards | 0 errors | 214331 discards |
| 11-May-2011 | 11:00 AM | 0 errors | 0 discards | 0 errors | 428663 discards |
| 11-May-2011 | 11:30 AM | 0 errors | 0 discards | 0 errors | 214332 discards |
| 11-May-2011 | 12:00 PM | 0 errors | 0 discards | 0 errors | 214332 discards |
11-May-2011 07:00 AM 0 errors 0 discards 0 errors 0 discards
11-May-2011 07:30 AM 0 errors 0 discards 0 errors 214331 discards
11-May-2011 08:00 AM 0 errors 0 discards 0 errors 0 discards
11-May-2011 08:30 AM 0 errors 0 discards 0 errors 428662 discards
11-May-2011 09:00 AM 0 errors 0 discards 0 errors 428662 discards
11-May-2011 09:30 AM 0 errors 0 discards 0 errors 0 discards
11-May-2011 10:00 AM 0 errors 0 discards 0 errors 0 discards
11-May-2011 10:30 AM 0 errors 0 discards 0 errors 214331 discards
11-May-2011 11:00 AM 0 errors 0 discards 0 errors 428663 discards
11-May-2011 11:30 AM 0 errors 0 discards 0 errors 214332 discards
11-May-2011 12:00 PM 0 errors 0 discards 0 errors 214332 discards
There are periods where the traffic is high (80%) and 0 discards are reported. Later, while the discards are high there is virtually no traffic.
If transmit discards = Total output drops, the counters don't seem to match
Full-duplex, 100Mb/s, media type is 10/100BaseTX input flow-control is off, output flow-control is unsupported ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:00, output 00:00:07, output hang never Last clearing of "show interface" counters 04:31:27 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 2 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 369000 bits/sec, 213 packets/sec 5 minute output rate 1353000 bits/sec, 240 packets/sec 3763964 packets input, 898014807 bytes, 0 no buffer Received 286700 broadcasts (256138 multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 256138 multicast, 0 pause input 0 input packets with dribble condition detected 3516065 packets output, 2339027985 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 PAUSE output 0 output buffer failures, 0 output buffers swapped out Can anyone shed some light on this issue? Thanks!