increasing buffer values

denis.roy · ‎06-22-2006

I do a sh buffer; I can see a large number of failures. The first thing I like to do is to reset the counters. And I can't find the command, anyone care to help?

answanso · ‎06-22-2006

Why are you concerned about the amount of buffer failures? Are they do to lack of memory (you will see the no mem counter increase if that is the case). Buffer failures occur naturally on a router when we attempt to allocate a buffer (at interrupt level) and there is not one available. We can not grow the buffer pool under interrupt, so we fail, then allocate more buffers to the pool. I don't know why a lot of people worry about this...Are you seeing latency? Can you please post the following information:

- show ver

- show buffer

You can not reset the counters on the buffer pool. You must reload the router to do this. In 98.99999999% buffer tuning is unnecessary and there is no real issue to worry about.

HTH

Anthony

hannyong · ‎07-27-2006

Hi Anthony,

Do I need to worry if the no memory counters keep increasing under the show buffer?

------------------ show version ------------------

Cisco Internetwork Operating System Software

IOS (tm) C3550 Software (C3550-I5Q3L2-M), Version 12.1(13)EA1a, RELEASE SOFTWARE (fc1)

Compiled Tue 25-Mar-03 23:42 by yenanh

Image text-base: 0x00003000, data-base: 0x007C34B0

ROM: Bootstrap program is C3550 boot loader

L43550C uptime is 19 weeks, 6 days, 13 hours, 58 minutes

System returned to ROM by power-on

System image file is "flash:c3550-i5q3l2-mz.121-13.EA1a/c3550-i5q3l2-mz.121-13.EA1a.bin"

cisco WS-C3550-24 (PowerPC) processor (revision J0) with 65526K/8192K bytes of memory.

Processor board ID CAT0727R10P

Last reset from warm-reset

Bridging software.

Running Layer2/3 Switching Image

Ethernet-controller 1 has 12 Fast Ethernet/IEEE 802.3 interfaces

Ethernet-controller 2 has 12 Fast Ethernet/IEEE 802.3 interfaces

Ethernet-controller 3 has 1 Gigabit Ethernet/IEEE 802.3 interface

Ethernet-controller 4 has 1 Gigabit Ethernet/IEEE 802.3 interface

24 FastEthernet/IEEE 802.3 interface(s)

2 Gigabit Ethernet/IEEE 802.3 interface(s)

The password-recovery mechanism is enabled.

384K bytes of flash-simulated non-volatile configuration memory.

Base ethernet MAC Address: 00:0D:65:1F:C7:00

Motherboard assembly number: 73-5700-10

Power supply part number: 34-0966-02

Motherboard serial number: CAT0727050S

Power supply serial number: DTH07260B1G

Model revision number: J0

Motherboard revision number: A0

Model number: WS-C3550-24-EMI

------------------ show buffers ------------------

Buffer elements:

484 in free list (500 max allowed)

70241924 hits, 0 misses, 0 created

Public buffer pools:

Small buffers, 104 bytes (total 50, permanent 50):

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

30442184 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

Middle buffers, 600 bytes (total 25, permanent 25, peak 40 @ 7w0d):

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

3485303 hits, 9 misses, 27 trims, 27 created

0 failures (0 no memory)

Big buffers, 1524 bytes (total 145, permanent 128, peak 4363 @ 7w0d):

137 in free list (128 min, 512 max allowed)

32019671 hits, 587639 misses, 29789 trims, 29806 created

8541 failures (76648 no memory)

VeryBig buffers, 4520 bytes (total 0, permanent 0):

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

0 hits, 225 misses, 0 trims, 0 created

225 failures (450 no memory)

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

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

0 hits, 225 misses, 0 trims, 0 created

225 failures (450 no memory)