Configuration error - bundled etherchannel ports

[emeyebee]

Hello to everyone on this form, fellow beginners and experts

Working with 2960 series switches, I have implemented PagP bundled configuration, to work as trunk forwarding ports.
The configuration is the same for each port on both Switch A and Switch B, the same interface port numbers.

However when linking the switches, one port always goes down, and the other flahes to amber every few seconds,
during this time network traffic drops. When it goes back to green; network traffic is normal.

I have run several commands to check, the status, stp states and if there are any blocked states.

I have performed the configurations few times, but it is always the same result as above.

The below screen shot, does not represent the actual devices being troubleshoot

The various commands for both switches are attached :

File1 : HRswitch

File 2: Core2switch


Also noticed when checking etherchannel summary; it only shows one display member, instead of two; even though the 2 ports are already assigned to the right channel group.
This from Switch A

From Switch B

I have been stuck on this for days, any help or guide to resolve this would be much appreciated.

[marce1000]

        >....However when linking the switches, one port always goes down, and the other flahes to amber every few seconds,
                                         - Check the logs on all involved switches when  that happens , 

 M.

[emeyebee]

Yes the logs were checked,
It did identify the change of states of each interface and the channel-group

[Giuseppe Larosa · Accepted solution]

Hello @emeyebee ,

some Catalyst 2950 platforms have this limitation that they are not able to have two active members in the same port-channel.

You may be facing this issue. If this is the case there is no workaround and the second link is just a cold standby

Hope to help

Giuseppe

[emeyebee]

Yes a test was made with 3850 switches instead, with the same configurations and it worked perfect !

Switching to the 2960 and 3850, with the former - same issue, so for now we have only configured it as a single trunk port, and not bundled.