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cisco output Errors


can anyone help me to explain the meaning of "Output Errors" in fastethernet interface. Because i getting huge amount of output error (even more than collision). please see below

hk4500#show interface

FastEthernet0 is up, line protocol is up

Hardware is DEC21140, address is 0060.5c5d.640a (bia 0060.5c5d.640a)

Internet address is

MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set, keepalive set (10 sec)

Half-duplex, 100Mb/s, 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters never

Queueing strategy: fifo

Output queue 0/40, 0 drops; input queue 0/75, 16832 drops

5 minute input rate 326000 bits/sec, 92 packets/sec

5 minute output rate 345000 bits/sec, 79 packets/sec

373691966 packets input, 1195415698 bytes, 0 no buffer

Received 121271343 broadcasts, 0 runts, 46 giants, 5006 throttles

161 input errors, 161 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

0 watchdog, 0 multicast

89 input packets with dribble condition detected

280142390 packets output, 566364375 bytes, 0 underruns

613536 output errors, 443171 collisions, 2 interface resets

0 babbles, 59 late collision, 0 deferred

189 lost carrier, 189 no carrier

0 output buffer failures, 0 output buffers swapped out



VIP Purple

Re: cisco output Errors

Hello Raymond,

output errors ussually mean that the device receives too much traffic to hand it off to the internal buffers. When you do a show buffers, you probably see a lot fo misses as well. Try to identify the source of the traffic, e.g. with a sniffer, there is a good, free one available at

Also check out this link for more info on the output of the show interface (fast)ethernet command:



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