buffer problem?

[kevintang]

Why do I lost packets in big buffer and verybig buffer? I still have a lot of free memory.

Any idea?

Router#sh buffer

Buffer elements:

500 in free list (500 max allowed)

6302252 hits, 0 misses, 0 created

Public buffer pools:

Small buffers, 104 bytes (total 200, permanent 200):

199 in free list (20 min, 300 max allowed)

3098752 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

Middle buffers, 600 bytes (total 200, permanent 200):

199 in free list (10 min, 200 max allowed)

518940 hits, 0 misses, 0 trims, 0 created

0 failures (0 no memory)

Big buffers, 1524 bytes (total 200, permanent 200):

200 in free list (5 min, 300 max allowed)

347520 hits, 14853 misses, 3583 trims, 3583 created

8657 failures (1928 no memory)

VeryBig buffers, 4520 bytes (total 30, permanent 30):

30 in free list (0 min, 50 max allowed)

139949 hits, 3658 misses, 265 trims, 265 created

6786 failures (3393 no memory)

Large buffers, 5024 bytes (total 30, permanent 30):

30 in free list (0 min, 50 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)

4 hits, 4 misses, 4 trims, 4 created

0 failures (0 no memory)

Interface buffer pools:

Ethernet0 buffers, 1524 bytes (total 32, permanent 32):

8 in free list (0 min, 32 max allowed)

1061 hits, 19107 fallbacks

8 max cache size, 8 in cache

Serial0 buffers, 1524 bytes (total 32, permanent 32):

7 in free list (0 min, 32 max allowed)

675 hits, 18753 fallbacks

8 max cache size, 7 in cache

Serial1 buffers, 1524 bytes (total 32, permanent 32):

6 in free list (0 min, 32 max allowed)

6156 hits, 0 fallbacks

8 max cache size, 8 in cache

Router#

Router#sh mem

Head Total(b) Used(b) Free(b) Lowest(b) Largest(b)

Processor 5F9DC 7992868 1514864 6478004 6230388 6463940

I/O 800000 2097152 1031656 1065496 96976 1065240

[kkalaycioglu]

Fields to worry about here are "no memory " fields in the big and very big buffers. Are these couters increasing? For a stable data flow pattern these values should stop increasing. You can monitor these values for a few days. In case of a remarkable increase you may think about buffer tuning. Link below may help:

http://www.cisco.com/en/US/customer/products/hw/routers/ps133/products_tech_note09186a00800a7b80.shtml

[Richard Gallagher]

Try the following buffer changes to see if it helps, you will need to reload the router after you have added the config:

buffer big permanent 260

buffer big min-free 78

buffer big max-free 371

buffer verybig permanent 39

buffer verybig min-free 11

buffer verybig max-free 55

[kevintang]

Hi, kkalaycioglu & rgallagh

Thanks for your replay. I have viewed that web link before I post my question. It’s not really helping me for my problem here.

I have been monitoring my router for the last a few days. Definitely there is no memory leaking and buffer leaking. But I still got "no memory" incrementing for big buffer and very big buffer even I have plenty free memory in the router.

I will adjust the buffer settings and reload the router. Keep monitoring the router for a few days.

My next question is that: If I see some input errors from some of the router interface, is that will cause this buffer “no memory” incrementing?