Untagged traffic on dot1q-tunnel interface

[ngimmill]

Hello,

We are using QinQ in a classical way to exchange customer vlans between two switches ( catalyst 3750G-12S-E ).

On site A , a customer has 3 ports configured in dot1q-tunnel

Port 1 : Tagged traffic from vlan 500 to vlan 510

Port 2 : Untagged traffic

Port 3 : Tagged traffic from vlan 700 to vlan 710

It is not possible for the customer to "pre tag" the traffic coming on port 2.

On site B , the customer need 1 port configured in dot1q-tunnel to get data from his 3 ports on site A.

He asked us to have the untagged traffic from site a / port 2 tagged ( 600 ) when exiting our switch on site B.

We have tried to add the tag with the switchport trunk native vlan command  :

interface GigabitEthernet1/0/2
 switchport access vlan 50
 switchport trunk native vlan 600
 switchport mode dot1q-tunnel

But it doesn't work. We have tried with and without the vlan dot1q tag native global command on the two switches.

Data coming from customer's port 2 on site A are always received untagged on customer port on site B.

Is it possible to add a 600 vlan tag on the port 2 on site A where the traffic comes untagged before the encapsulation in the outer vlan ?

Switches : WS-C3750G-12S

IOS : Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 12.2(55)SE10, RELEASE SOFTWARE (fc2)

Thanks

[Philip D'Ath]

I don't know the answer.

Perhaps look at the "vlan dot1q tag native" command.

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/12-2_55_se/configuration/guide/3750xscg/swtunnel.html

[ngimmill]

As we said above, we tried with and without the "vlan dot1q tag native" and it made no difference.

[Adel Barashed]

These are some ways to solve this problem:

• Use ISL trunks between core switches in the service-provider network. Although customer interfaces connected to edge switches must be IEEE 802.1Q trunks, we recommend using ISL trunks for connecting switches in the core layer.
• Use the vlan dot1q tag native global configuration command to configure the edge switch so that all packets going out an IEEE 802.1Q trunk, including the native VLAN, are tagged. If the switch is configured to tag native VLAN packets on all IEEE 802.1Q trunks, the switch accepts untagged packets, but sends only tagged packets.
• Ensure that the native VLAN ID on the edge-switch trunk port is not within the customer VLAN range. For example, if the trunk port carries traffic of VLANs 100 to 200, assign the native VLAN a number outside that range.