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New Member

Question about input queue in show interfaces output

I have a catalyst 4006 with processor III, level 3, and in the show interfaces output the “input queue” in very very high, in several of they, but no droop paquets.

For example

FastEthernet2/47 is up, line protocol is up

Hardware is Fast Ethernet Port, address is 000a.8a35.03be (bia 000a.8a35.03be)

Description: "acd"

MTU 1500 bytes, BW 10000 Kbit, DLY 100 usec,

reliability 253/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Half-duplex, 10Mb/s

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

Last input 00:00:06, output never, output hang never

Last clearing of "show interface" counters 20:14:51

Input queue: 1714889/2000/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

1810861 packets input, 360397463 bytes, 0 no buffer

Received 15945 broadcasts, 0 runts, 0 giants, 0 throttles

18307 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 input packets with dribble condition detected

2623836 packets output, 329147904 bytes, 0 underruns

35247 output errors, 35183 collisions, 0 interface resets

0 babbles, 0 late collision, 0 deferred

0 lost carrier, 0 no carrier

0 output buffer failures, 0 output buffers swapped out

I see that the input queue is “”Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped because of a full queue. “” but I have a doubt.

The question is ¿ this input queue high is a dangerous condition for the catalyst ó what means ?

And other question is ¿ this counter cab be reseted and how ?

Please help me,



Re: Question about input queue in show interfaces output

Yes, this could become a problem if left unattended to. It might halt your Switch from forwarding any more packets.

Most of the times, this could be due to software bug (buffer leak) and upgrading to a latest version of IOS might fix the issue.

In case you cannot upgrade right now, you could try the 'show buffers old' and 'show buffers input-interface FastEthernet2/47'

commands to pinpoint the source of the buffer leak and filter the problematic packets.

This documents explains the process in more detail.


New Member

Re: Question about input queue in show interfaces output

OK, then I will look for source of buffer leak

Thank for your help


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