"BUFFER FAILURES" Catalyst 2950

jroldanvaldellos · ‎10-04-2007

Hello mates,

I am having some difficults finding the reason why buffers at all my Catalyst 2950 are being incremented in all the buffers.

As I ve been reading at the output interpreter and some Ciscos Docs failures are equal to drop packets.

Here I ve pasted a few outputs commands from one of this Catalyst 2950.

My question is:

Does anybody understand this? Is there any way to solve it?

The output interpreter saids that packets are being dropped but cpu and memory seems to be ok.

Thanks in advance to all of the networkers.

sh ver

Cisco Internetwork Operating System Software

IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA7, RELEASE

sh buffer

Buffer elements:

499 in free list (500 max allowed)

139451641 hits, 0 misses, 0 created

Public buffer pools:

Small buffers, 104 bytes (total 60, permanent 25, peak 181 @ 5w2d):

60 in free list (20 min, 60 max allowed)

483868967 hits, 10495037 misses, 11333498 trims, 11333533 created

590919 failures (0 no memory)

Middle buffers, 600 bytes (total 36, permanent 15, peak 110 @ 5w2d):

32 in free list (10 min, 30 max allowed)

15212634 hits, 980925 misses, 492011 trims, 492032 created

484141 failures (0 no memory)

Big buffers, 1524 bytes (total 10, permanent 5, peak 27 @ 5w2d):

10 in free list (5 min, 10 max allowed)

4152603 hits, 4845901 misses, 1054876 trims, 1054881 created

4087385 failures (0 no memory)

VeryBig buffers, 4520 bytes (total 10, permanent 0, peak 30 @ 03:10:54):

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

5558664 hits, 2773806 misses, 304006 trims, 304016 created

2682686 failures (0 no memory)

Large buffers, 5024 bytes (total 5, permanent 0, peak 7 @ 5w2d):

5 in free list (0 min, 5 max allowed)

606029 hits, 2076657 misses, 102597 trims, 102602 created

2076657 failures (0 no memory)

Huge buffers, 18024 bytes (total 2, permanent 0, peak 4 @ 5w2d):

2 in free list (0 min, 2 max allowed)

211191 hits, 1865466 misses, 97602 trims, 97604 created

1865466 failures (0 no memory)

jroldanvaldellos · ‎10-04-2007

Here also is pasted the sh tech from the cat2950 in question.

Thanxs 2 all.

Jayakrishna Mada · ‎10-05-2007

A "Miss" can occur if the number of buffers in the free list is less than the "Min" value. A "Failure" is when no buffers were available

that is

"Miss" does not mean packet drop.

"Miss" and "Failure" means a drop packet

You can use the buffer tuning tool to tune the buffers

http://www-tac.cisco.com/Teams/Cats/buffertool.html

glen.grant · ‎10-05-2007

Personally i have never heard of tuning buffers on a layer 2 switch . It s possible that you are overloading that low end switch and you should think about getting something more robust . On the interfaces look at see what all the traffic is , is it large amount of broadcast traffic , is someone multicasting and nothing is setup to handle something like this .

jroldanvaldellos · ‎10-05-2007

First of all thanxs for this fast reply to both of you.

I don?t have it very clear in order to modify the buffers as recomended by Cisco as Cat 2950 are not very big in memory.

And as Glen said it could be a way to solve this issue to move into a bigger choice like Cat 3750 but not to sure and not very technical.

That traffic must be studied as it seems to be most of it broadcast.

I?ve reloaded that Catalyst in order to check error clearing counters and the buffers are incrementing always.

Seem to be a problem that overload the buffers.

DO any of you gays know a solutions for this type of issue? Storm-control ...

Thanxs in advance