Re: Etherchannel issue, Port-Channel down down but correctly con
since you problem is solved with a shutdown / no shutdown, I just explain about the secondary port creation (Po4A/B):
Here are a few probable causes which trigger such issues (Creation of a Secondary Port Channel) with LACP port channels:
1. Adding a new port to an existing port channel. If any configuration mismatch is seen on the newly added port, it will be added to Secondary port-channel as you can see (Here, Po4A)
2. Configuration mismatch on the ports bundled in the port channel.
3. Configuration mismatch on the interfaces of the far end device can also create inconsistency between the ports bundled in the port channel.
This is expected behavior. The exact reason will be shown in the Logs while adding the port to port-channel.
'mls qos channel-consistency' is one of the reason which will put the port in to secondary port-channel.
The first step to resolve this issue is to look for the command "mls qos channel-consistency" in the interface configuration or to recreate the port channel following the best practices mentioned below.
The best practices in resolving port channel issues are:
1. Manually shut the bundled interfaces and the port channel interface down on both the end. 2. Then reset the interface configuration to default.
3. Reconfigure the interfaces to be bundled and assign them to the port channel. 4. Verify the configuration of the interfaces. 5. Bring up the interfaces after the configuration has been verified.
This is a known and an expected behavior with LACP. If LACP is not a mandatory requirement, you may recreate the port channel with the channel mode "ON".
The configuration doesn't match on the two switches for the Port-Channel as you've allowed different VLANs on the trunks, therefore it created the secondary aggregator ports.
"An EtherChannel supports the same allowed range of VLANs on all the LAN ports in a trunking Layer 2 EtherChannel. If the allowed range of VLANs is not the same, the LAN ports do not form an EtherChannel."
Here I'm just assuming your port configuration.. Are you sure a shut/no shut fixed this?
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...