Inconsistent etherchannel configuration 3850-XS

[1977bjorn]

Hi,

I searched bug tool and other resources for this behaviour. Am I missing somthing obvious, or is this a bug?

Configuration is not saved to port channel interface. It´s also removed when shutting down a port channel, like "conf t - int po1 - shut - no shut"...

also:

(config)#int po1
(config-if)#desc Core
(config-if)#switchport mode trunk
(config-if)#int te1/1/1
(config-if)#desc Core
(config-if)#channel-group 1 mode active
(config-if)#inte ten1/1/2
(config-if)#channel-group 1 mode active
(config-if)#desc Core
(config-if)#exit
(config)#exit
#wr
#sh runn int po1
Building configuration...

Current configuration : 49 bytes
!
interface Port-channel1
description Core
end

Someone seen this behaviour before?

Model is WS-C3850-48XS Version 16.8.1a

[marce1000]

 - Did you configure the member interfaces first ?

M.

[1977bjorn]

No, I did it just like the snippet above. This snippet/configuration was made just to verify the problem and can be reproduced.

A collegue of mine pointed out that I had missed some configuration the first time it happened. Oh well, that could happen of course (That I missed some config), but when it happened a second time I was sure that I had not missed it. I went back in the configuration logs in my terminal program and verified that I had not missed it. Reproduced the snippet above just to verify.

[1977bjorn]

I mean, one could argue that member switchport configuration could differ in one portchannel bundle, and therefore, one should do the member switchport configuration before joining them to a port channel, but I have not seen this behaviour before.

[marce1000]

>one should do the member switchport configuration before joining them to ...

 - I believe it would be advisable to work that way.

M.

[paul driver · Accepted solution]

Hello

L2 etherchannel

1. default physical interfaces (if possible)
2. configure port-channel in physical interfaces
    ---port-channel will be created automatically
3. create trunking encapsulation or access port mode directly in port-channel interface
4. enable physical interfaces "no shut"
   
   
   
   

conf t
default int range te1/1/1 -2
int range te1/1/1 -2
shut
channel-group 1 mode active
exit

int po1
switchport mode trunk
switchport trunk allowed vlan x x x
exit

int range te1/1/1 -2
no shut
exit

res
Paul

[1977bjorn]

This seems to work. However, I´m not able to reproduce the problem anymore, no matter how I configure it. The one thing that differs is that I´m not able to try it on a live port as it is in production now...

I will keep an eye on this an post any changes if there are any. Thanks for all your input.