Output drops on port channel issue

ssinfra · ‎05-11-2020

Hi All

I have a 3650 and a 3750 linked together via a port channel and I am getting output drops on the 3650 side of the port channel. I ahve placed some info below, let me know if you need any more data to help me troubleshoot why I am getting Tx errors on the one switch.

Switch Ports Model SW Version SW Image Mode

------ ----- ----- ---------- ---------- ----

* 1 28 WS-C3650-24TD 03.06.04.E cat3k_caa-universalk9 INSTALL

Some show commands:

show system mtu

Global Ethernet MTU is 1500 bytes.

show run | inc soft

qos queue-softmax-multiplier 200

Port configuration:

!

interface GigabitEthernet1/0/24

description net-cbs-prd-001_1/0/24

switchport mode trunk

channel-protocol lacp

channel-group 50 mode active

end

!

interface GigabitEthernet1/0/23

description net-cbs-prd-001_2/0/24

switchport mode trunk

channel-protocol lacp

channel-group 50 mode active

end

Port-channel50 is up, line protocol is up (connected)

Hardware is EtherChannel, address is 00f6.63e2.fb97 (bia 00f6.63e2.fb97)

MTU 1500 bytes, BW 2000000 Kbit/sec, DLY 10 usec,

reliability 250/255, txload 2/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is auto, media type is

input flow-control is off, output flow-control is unsupported

Members in this channel: Gi1/0/23 Gi1/0/24

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output never, output hang never

Last clearing of "show interface" counters never

Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 9884000 bits/sec, 1695 packets/sec

5 minute output rate 18096000 bits/sec, 3407 packets/sec

353968677024 packets input, 369281676384302 bytes, 0 no buffer

Received 1255496791 broadcasts (1013407362 multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 1013407362 multicast, 0 pause input

0 input packets with dribble condition detected

400826175206 packets output, 383363433855944 bytes, 0 underruns

1062078557 output errors, 0 collisions, 1 interface resets

0 unknown protocol drops

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

Switch Ports Model SW Version SW Image

------ ----- ----- ---------- ----------

* 1 28 WS-C3750G-24TS 12.2(55)SE5 C3750-IPBASEK9-M

2 28 WS-C3750G-24TS 12.2(55)SE5 C3750-IPBASEK9-M

Some show commands:

Port Configuration:

!

interface GigabitEthernet1/0/24

description net-ics-prd-002_1/0/24

switchport trunk encapsulation dot1q

switchport mode trunk

channel-protocol lacp

channel-group 42 mode active

end

!

interface GigabitEthernet2/0/24

description net-ics-prd-002_1/0/23

switchport trunk encapsulation dot1q

switchport mode trunk

channel-protocol lacp

channel-group 42 mode active

end

Port-channel42 is up, line protocol is up (connected)

Hardware is EtherChannel, address is 000f.8fd5.a618 (bia 000f.8fd5.a618)

MTU 9000 bytes, BW 2000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 2/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is auto, media type is unknown

Media-type configured as connector

input flow-control is off, output flow-control is unsupported

Members in this channel: Gi1/0/24 Gi2/0/24

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 never

Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 3650699

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 18648000 bits/sec, 3417 packets/sec

5 minute output rate 9881000 bits/sec, 1687 packets/sec

417435748682 packets input, 405214976425882 bytes, 0 no buffer

Received 5004004048 broadcasts (2928468163 multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 2928468163 multicast, 0 pause input

0 input packets with dribble condition detected

363670706828 packets output, 378337160283941 bytes, 0 underruns

0 output errors, 0 collisions, 5 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

Leo Laohoo · ‎05-11-2020

@ssinfra wrote:

* 1 28 WS-C3650-24TD 03.06.04.E cat3k_caa-universalk9 INSTALL

Upgrade the IOS to something more recent first.

Please take the time to read the following:

FN - 64191 - Catalyst 3850/3650 Switches That Run Cisco IOS XE Releases 3.6.5E/3.7.4E or Earlier Might Exhibit High CPU Usage
FN - 70110 - Memory Leak Issue on C3850/C3650 Switches That Run Polaris Software Version 16.3.3 or Earlier

Georg Pauwen · ‎05-11-2020

Hello,

the reliablity should be 255/255, if it is not, it could indicate a physical problem. Which of the two interfaces in the 3560 port channel are showing errors as well ? Try and use another port and/or cable for the port channel on the 3560, in order to find out if the problem is with one of the ports on the 3560...

Port-channel50 is up, line protocol is up (connected)

Hardware is EtherChannel, address is 00f6.63e2.fb97 (bia 00f6.63e2.fb97)

MTU 1500 bytes, BW 2000000 Kbit/sec, DLY 10 usec,

--> reliability 250/255, txload 2/255, rxload 1/255

ssinfra · ‎05-11-2020

Thanks for the heads up, I will check to see if its a physical issue, let me know if the below troubleshooting process is a good one

First swap the cables for known working cables and check to see if the issue has gone
if the above does not work, then try different switch ports in the same configuration.
if the above does not work, then relook at the configuration with a closer inspection and as a last case effort upgrade the code on the switches.

Thanks