cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
3051
Views
0
Helpful
1
Replies

Interface input errors on 2811

dkuan
Level 1
Level 1

Hi,

I have a 2811 router and both it's fastethernet interface input errors are increasing all the time. There are some middle buffer failures but it's not increasing as much as compared to the interface ignored errors. CPU utilization is around 30% only.

How can I verify that the problem is due to buffer overflow and how do i rectify this? Do i need a hardware upgrade?

FastEthernet0/0 is up, line protocol is up

...

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 8111000 bits/sec, 9478 packets/sec

5 minute output rate 3000 bits/sec, 4 packets/sec

1411473953 packets input, 1400382171 bytes

Received 140423 broadcasts, 0 runts, 0 giants, 0 throttles

1405554 input errors, 0 CRC, 0 frame, 0 overrun, 1405560 ignored

0 watchdog

0 input packets with dribble condition detected

...

FastEthernet0/1 is up, line protocol is up

...

Input queue: 0/75/3/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 1325000 bits/sec, 1020 packets/sec

5 minute output rate 8130000 bits/sec, 9491 packets/sec

236598977 packets input, 2722816511 bytes

Received 672071 broadcasts, 0 runts, 0 giants, 1 throttles

103659 input errors, 0 CRC, 0 frame, 0 overrun, 103659 ignored

0 watchdog

0 input packets with dribble condition detected

...

Buffer elements:

1118 in free list (500 max allowed)

21777319 hits, 0 misses, 1119 created

Public buffer pools:

Small buffers, 104 bytes (total 50, permanent 50, peak 74 @ 19:48:49):

38 in free list (20 min, 150 max allowed)

1836993 hits, 76 misses, 110 trims, 110 created

0 failures (0 no memory)

Middle buffers, 600 bytes (total 28, permanent 25, peak 37 @ 2d23h):

14 in free list (10 min, 150 max allowed)

67730 hits, 59 misses, 35 trims, 38 created

41 failures (0 no memory)

Big buffers, 1536 bytes (total 50, permanent 50):

50 in free list (5 min, 150 max allowed)

453756 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

VeryBig buffers, 4520 bytes (total 10, permanent 10):

9 in free list (0 min, 100 max allowed)

1 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

Large buffers, 5024 bytes (total 0, permanent 0):

0 in free list (0 min, 10 max allowed)

0 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

Huge buffers, 18024 bytes (total 0, permanent 0):

0 in free list (0 min, 4 max allowed)

0 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

1 Reply 1

drolemc
Level 6
Level 6

I suspect when ignored counter increases, CPU usage is high and Interface input traffic volume is large.

My first guess would be a frame type mismatch of some sort, or even a speed negoiation issue.

1) You have a bad cable. CRC and framing errors are usually a result of bad media.

2) You should set the port to auto/auto, not 100/Full hard set, unless you have specifically set that up in rc.conf. If one side is hard set and the other is set to auto, you will see lots of runts because of a duplex mismatch.

I suspect when ignored counter increases, CPU usage is high and interface input traffic volume is large.

For problems like this its best to include as much output from the device as you can, as well as as much data about it, i.e whats it doing, whats it connected to, whats working or not working, etc.

Additionally you probably want to use the "clear counters" command and see if the input errors are still coming in. Its possible these errors are old and were caused by a temporarily disconnected cable, etc. Before you go troubleshooting the problem further, clear the counters and see if you even have a problem.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: