cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
1607
Views
0
Helpful
2
Replies

vlan dot1q tag native : impact

langoustator
Level 1
Level 1

Hi,

In order to follow the best practices fro QinQ, I need to enable native vlan tagging. As it's a global command, i have concerns about the impact on the existing infrastructure. Can it impact stp in some way, and is it mandatory to perform it on all backbone switchs (I mean even the ones that are only forwarding QinQ frames without being extremities of the tunnels), knowing that :

- native vlan is never allowed in trunks

- the backbone is a mix between Cisco 6500 and other brands (Extreme, HP)

Thanks

2 Replies 2

Florin Barhala
Level 6
Level 6

Always remember, if the native VLAN is different from VLAN1 then:


1. VLAN1 standard STP BPDU is sent untagged

2. VLAN1 PVST+ BPDU is sent tagged with VLAN1

3. Other VLAN's PVST+ BPDUs are sent tagged accordingly      (the one for the native VLAN will be untagged).

Then, tell us what is the native vlan on your trunk and what STP flavor are you using?

Thanks for the answer,

Native vlan is vlan 1 and switches are running PVST+.

Review Cisco Networking for a $25 gift card