Show Interface Input Errors

[monkp]

When doing a show inteface - What do Input Errors indicate?

[ankurbhasin]

HI Monkp,

The input errors includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input error count to be increased, and some datagrams may have more than one error.

Have a look at this link

http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1904.htm#wp1020942

HTH

Ankur

[monkp]

Ankur,

Here is the output from show int ...The only thing incrementing is the input errors but what type of problem does that indicate?

JSC-1#sh int gigabitEthernet 11/1

GigabitEthernet11/1 is up, line protocol is up (connected)

Hardware is C6k 1000Mb 802.3, address is 0012.0092.a260 (bia 0012.0092.a260

Description: GL1

MTU 1500 bytes, BW 100000 Kbit, DLY 10 usec,

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

Encapsulation ARPA, loopback not set

Full-duplex, 100Mb/s

input flow-control is off, output flow-control is off

Clock mode is auto

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

Last input never, output 00:00:35, output hang never

Last clearing of "show interface" counters 1d03h

Input queue: 0/2000/41/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 645000 bits/sec, 66 packets/sec

5 minute output rate 305000 bits/sec, 63 packets/sec

1152632 packets input, 910547914 bytes, 0 no buffer

Received 2068 broadcasts (1650 multicast)

0 runts, 0 giants, 0 throttles

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

0 watchdog, 0 multicast, 0 pause input

0 input packets with dribble condition detected

1917609 packets output, 964325920 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

[ankurbhasin]

hi monkp,

Congestion in network on interface can result in inpur errors or any bad packets processed by the interface may result in input errors.

Regards,

Ankur

[Steve Fuller]

You'll notice that the "input errors" count is exactly the same as the "drops" shown on the Input queue line. This means that the packet that caused the input error was dropped by the router as the input queue for the interface was already full.

This problem can be caused by the fact the TX ring on the egress interface is full, typically due to the ingress interface being of a much higher speed than the egress interface.

Also take a look at "Troubleshooting Input Queue Drops" at http://www.cisco.com/en/US/partner/products/hw/routers/ps133/products_tech_note09186a0080094791.shtml#topic2.

Regards

Steve