Hi there, i have 2 switches, a 2960 and a 3750 connected with trunk links. In the 3750 switch i have the native vlan tagging on. On 2960 i was told by cisco personnel that i doesn't support native vlan tagging. Though, i have placed a sniffer on the 3750 and i get tagged and untagged frames. Isn't it a little strange? Shouldn't the 3750 reject all the untagged frames?
Well. 2960 is sending the untagged frame for native vlan across the trunk and is expecting the same from 3750. once the 3750 receives the untagged frame, it will drop it and will result in a trunk port misconfiguration error.
You should enable the native vlan tagging on both the sides. You can also get away with this by using a bogus vlan as a native vlan on the trunk ports. This way all the user data vlans will be tagged across the trunk link.
pings during this config might/might not work but this is not a recommended config. If this condition is true then the switches will be buffering the logs. This would significantly impact the performance over the lan.
Please paste the "show log " and " show config " from both the switches.
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...