Hi all,
I've got a strange one that I'm pulling my hair out trying to work out. We've got a Cisco 7301 connected to a 3750 that's showing a lot of buffer underruns when transmitting to the 3750.
The 7301's config is as follows:
interface GigabitEthernet0/2
description Gi0/2 Trunk
mtu 1600
no ip address
load-interval 30
media-type rj45
speed auto
duplex auto
negotiation auto
hold-queue 1024 in
hold-queue 1024 out
end
The 3750's config is as follows:
interface GigabitEthernet1/0/4
description Gi1/0/4 CORE-Gi0/2
switchport trunk encapsulation dot1q
switchport mode trunk
hold-queue 1024 in
hold-queue 1024 out
end
Here's the output from Gi0/2 on the 7301:
GigabitEthernet0/2 is up, line protocol is up
Hardware is BCM1250 Internal MAC, address is xxxxxxxxxxxx
Description: Gi0/2 Trunk
MTU 1600 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 245/255, txload 3/255, rxload 7/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set
Keepalive set (10 sec)
Full Duplex, 1000Mbps, media type is RJ45
output flow-control is XON, input flow-control is XON
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters 01:05:55
Input queue: 0/1024/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/1024 (size/max)
30 second input rate 27546000 bits/sec, 4091 packets/sec
30 second output rate 12483000 bits/sec, 3398 packets/sec
16912174 packets input, 1720623525 bytes, 0 no buffer
Received 14168 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 91077 multicast, 0 pause input
14743902 packets output, 2948242260 bytes, 1223851 underruns
1223851 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
And on the 3750:
GigabitEthernet1/0/4 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is xxxxxxxxxxxxxxxx
Description: Gi1/0/4 CORE-Gi0/2
MTU 2000 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 241/255, txload 7/255, rxload 3/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:31, output 00:00:00, output hang never
Last clearing of "show interface" counters 00:54:33
Input queue: 0/1024/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/1024 (size/max)
5 minute input rate 11807000 bits/sec, 2301 packets/sec
5 minute output rate 27530000 bits/sec, 3988 packets/sec
9186933 packets input, 1829460673 bytes, 0 no buffer
Received 64 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
1187716 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 60 multicast, 0 pause input
0 input packets with dribble condition detected
14223320 packets output, 3655786359 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
When I clear counters, I see the error rate at around 3-400 underruns per second.. Here's a graph showing traffic and errors associated with that port. There's not an overly large amount of traffic present so I don't think it's a buffer issue.
The 7301 is running c7301-adventerprisek9-mz.122-33.SRC5.bin and the 3750 is running c3750-ipbase-mz.122-25.SEE3.bin
Cheers, Mike
