Vlan tagging troubleshooting

[j-schmidt]

Hello,

is there a way to check if a device connected  to my Cisco Router sends me packets tagged with the wrong Vlan?

The other device is not a Cisco device an I have no access to check it.

I have not configured any Vlan on my interface but I guess the other device sends me tagged packets.

How can I check this without changing my configuration (show or debug commands)?

[balaji.bandi]

debug vlan packet should give you what you looking for, but if this in production be aware of side effect if you running long.

Another option is SPAN to port and analyze the best approach.