I added a new vlan to a switch and then needed to allow it on port-channel interfaces. Two additions to port-channels were fine, but with the other two, when I added the new vlan
(switchport trunk allow vlan add <vlan>), the last existing vlan disappeared from the running configuration in the interface.
However, it was still present in 'show int trunk'.
Removing my new vlan from the interface, brought the other vlan back into the config.
On the interfaces where I had a problem, there were already quite a few vlans allowed. On the interfaces where I didn't have the problem, there were not so many.
Is this a cosmetic display error that will not cause a problem, or would the switch reload without the missing vlan?
Thanks in advance.