buffer misses on routers

[schimekh]

Hi !

On several routers we found "buffer misses". Could you please tell me to which problem this might lead ?

respectively why do these misses occur ?

Thx

Hans

[rajesh444]

Hi,

Can you post a copy of the "show buffers" output on the router?

The following link should be useful.

Understanding Buffer Misses and Failures:

http://www.cisco.com/en/US/customer/products/hw/modules/ps2643/products_tech_note09186a0080093fc5.shtml

Thanks,

Rajesh

[schimekh]

Hi !

Here you are:

Public buffer pools:

Small buffers, 104 bytes (total 98, permanent 50, peak 101 @ 7w0d):

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

31032593 hits, 60520 misses, 28383 trims, 28431 created

27490 failures (0 no memory)

Middle buffers, 600 bytes (total 36, permanent 25, peak 50 @ 7w0d):

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

3140382 hits, 8046 misses, 8298 trims, 8309 created

1287 failures (0 no memory)

Big buffers, 1536 bytes (total 50, permanent 50, peak 56 @ 7w0d):

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

1288128 hits, 62 misses, 6 trims, 6 created

58 failures (0 no memory)

VeryBig buffers, 4520 bytes (total 10, permanent 10, peak 11 @ 7w0d):

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

10 hits, 48 misses, 1 trims, 1 created

48 failures (0 no memory)

Large buffers, 5024 bytes (total 0, permanent 0, peak 1 @ 7w0d):

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

0 hits, 48 misses, 1 trims, 1 created

48 failures (0 no memory)

Huge buffers, 18024 bytes (total 0, permanent 0, peak 1 @ 7w0d):

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

0 hits, 48 misses, 1 trims, 1 created

48 failures (0 no memory)

THx

Hans

[rajesh444]

Hi,

Buffer misses counters are incremented when the router has to assign additional buffers to handle heavy traffic. However, buffer "failures" represent buffer shortage and consequently packet drops.

In your case, the Small buffer[104 bytes buffers] has high count of buffer failures but it should not be a cause for concern unless it is affecting network performance.

Do you see a lot of input/output drops on the interfaces?

Rajesh