Output Buffer Failure

[CHM1]

Hello,
On a C3548, I have many "Ouput Buffer Failures" on several ports, and obviously the connected PCs don'work fine (many fails)(see the end of this message). What could be the cause of this.
The sh Buffers command gives nothing :

Buffer elements:
480 in free list (500 max allowed)
1379669812 hits, 0 misses, 0 created

Public buffer pools:
Small buffers, 104 bytes (total 41, permanent 25):
35 in free list (20 min, 60 max allowed)
2780433213 hits, 26287 misses, 78669 trims, 78685 created
0 failures (0 no memory)
Middle buffers, 600 bytes (total 47, permanent 15):
26 in free list (10 min, 30 max allowed)
2222082226 hits, 51839 misses, 155594 trims, 155626 created
0 failures (0 no memory)
Big buffers, 1524 bytes (total 8, permanent 5):
7 in free list (5 min, 10 max allowed)
37679532 hits, 7113 misses, 21336 trims, 21339 created
0 failures (0 no memory)
VeryBig buffers, 4520 bytes (total 0, permanent 0):
0 in free list (0 min, 10 max allowed)
2542480 hits, 253 misses, 506 trims, 506 created
0 failures (0 no memory)
Large buffers, 5024 bytes (total 0, permanent 0):
0 in free list (0 min, 5 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, 2 max allowed)
5 hits, 2 misses, 4 trims, 4 created
0 failures (0 no memory)

Interface buffer pools:
CPU10 buffers, 64 bytes (total 32, permanent 32):
16 in free list (0 min, 32 max allowed)
16 hits, 0 misses
CPU11 buffers, 64 bytes (total 32, permanent 32):
16 in free list (0 min, 32 max allowed)
17181142 hits, 0 misses
CPU13 buffers, 1516 bytes (total 8, permanent 8):
4 in free list (0 min, 8 max allowed)
4 hits, 0 misses
CPU12 buffers, 1524 bytes (total 190, permanent 190):
94 in free list (0 min, 190 max allowed)
1790911686 hits, 25242201 misses
CPU0 buffers, 1524 bytes (total 32, permanent 32):
16 in free list (0 min, 32 max allowed)
16 hits, 0 misses
CPU1 buffers, 1524 bytes (total 32, permanent 32):
16 in free list (0 min, 32 max allowed)
21517009 hits, 0 misses
CPU2 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
3890525195 hits, 0 misses
CPU3 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
1178313401 hits, 0 misses
CPU4 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
1178313400 hits, 0 misses
CPU5 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
3890525194 hits, 0 misses
CPU6 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
3890525195 hits, 0 misses
CPU7 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
3890525204 hits, 0 misses
CPU8 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
3890525753 hits, 0 misses
CPU9 buffers, 1524 bytes (total 4, permanent 4):
2 in free list (0 min, 4 max allowed)
3890525753 hits, 0 misses


sh int fast 0/9 results (but other ports like this) :

FastEthernet0/9 is up, line protocol is up
Hardware is Fast Ethernet, address is 0004.dd61.aac9 (bia 0004.dd61.aac9)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Auto-duplex (Full), Auto Speed (100), 100BaseTX/FX
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:08, output hang never
Last clearing of "show interface" counters 1w0d
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 169000 bits/sec, 78 packets/sec
1042918 packets input, 140348023 bytes
Received 3591 broadcasts, 0 runts, 0 giants, 0 throttles
5 input errors, 5 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 541 multicast
0 input packets with dribble condition detected
25142198 packets output, 2260660990 bytes, 3191 underruns
1 output errors, 0 collisions, 0 interface resets
0 babbles, 1 late collision, 0 deferred
0 lost carrier, 0 no carrier
3191 output buffer failures, 0 output buffers swapped out

Thanks for a solution .

 

[CHM1]

I see that in fact Output buffer failures are Underruns.
"Underruns occur when packets are not retrieved quickly enough from shared memory to be transmitted" says Cisco. But Why ??

 

[davemiller]

your buffers may/maynot relate to the pc performance.
it looks like you could have several problems.

first:
your wiring from your nic to the switch may not be completely CAT5 - test circuit or set both ends to 10/half-duplex and see if errors cease. the duplex may be mismatched - verify the switch interface vs. the workstation.

second:
you may need to upgrade the switch ios, if you're a partner just do it cause its free, otherwise check ios release notes and bug fixes for your version and the next series to see if anything relates to your situation.

goodluck