VLAN - Q-IN-Q

[sebastienLen]

Hi everybody,

I would like to create a q in q vlan inside my network architecture but unfortunately i have only to 2941 router to do this functionality. I find several websites which describe q in q vlan cisco commands.
Finally I do the below configuration in my two tunneling routers :

#R1
enable
conf t
no ip routing
interface GigabitEthernet 0/0
no shut
interface GigabitEthernet 0/1
no shut
interface GigabitEthernet0/0.100
encapsulation dot1q 100 second-dot1q 2,3
no shut
interface GigabitEthernet0/1.2
encapsulation dot1q 2
no shut

interface GigabitEthernet0/1.3
encapsulation dot1q 3
no shut

#R2
enable
conf t
no ip routing
interface GigabitEthernet 0/0
no shut
interface GigabitEthernet 0/1
no shut
interface GigabitEthernet0/0.100
encapsulation dot1q 100 second-dot1q 2,3
no shut
interface GigabitEthernet0/1.2
encapsulation dot1q 2
no shut

interface GigabitEthernet0/1.3
encapsulation dot1q 3
no shut

I want to use my routers as  L2 switchs and I don t want to add ip address in my subinterfaces. I m not sure this configuration works. I would like know others possibilites to use this router like a switch ?

Thank you very much

regards

[Georg Pauwen]

Hello,

the config looks about right. Since you cannot convert the GigabitEthernet interfaces to true layer 2 ports, you cannot use the 'switchport mode dot1q-tunnel' command.

[sebastienLen]

Hi Georg,

so if i undestand, there are two solutions to solve my problem :
- buy two L2 switchs which use Q in Q vlan feature (switchport mode dot1q-tunnel)
- use my two old 1941 routers but doing L3 routing vlan.

If I choose the second solution, i must configure ip routing and ip address in each sub interface. Considerating my 1941 is not a good solution for me. In fact, i would like the Q in Q vlan to be transparent for my two routers (L3) interconnected to my two old 1941 routers.
It's right ?

Thank you