Q-in-Q lab, using IOU GNS3 L2-L3 Images, Unable to ping the R1 or R2

Dear Rene,

I believe you are doing great as always.

Rene, Followings your CCIE R&S labs and visited many other online sources claiming that GNS3’s IOU feature does support 95% of the switching incl L2 - L3.

And I have personally checked this feature and assures that it does support switching as claimed by many. However, while creating Q-in-Q tunneling lab, following your demo, I was although able to run all the required commands on the switches, but upon completing the lab connectivity & configs, I was unable to establish connectivity within the two routers.

For your ref, I am attaching the config & topology file. Kindly review it, if you could find something missing in it.


Many Thanks.


SW1.txt (1.3 KB)

SW2.txt (1.3 KB)

SW3.txt (1.3 KB)

Hi Ali,

I just took a look at the config files in your attachments but some of them are missing/incomplete. Could you take a look and reupload those?


Dear Rene,


Please find the attached files, it has all the required configs in switches/Routers as demonstrated in your guide.


Many Thanks


Hi Ali,

I just checked but these are also empty…:slight_smile: The router configs are fine but there’s nothing in SW1, SW2 or SW3.

Better to manually copy/paste the switch configs perhaps.


Hi Ali,

I just checked your configurations and they are looking fine. Is VLAN 123 in the database of SW3?

I’ll post my full configurations here tomorrow just in case, I tested this on real 3560 switches.


Hi Ali,

Quick update, I just tested this in VIRL and even though the configuration is possible, it doesn’t work.

The “show dot1q-tunnel” is also not support on the L2 IOU images.


Hello Rene! Did you try NX9k with jumbo instead l2 vIOS images?

It works here, for example

interface Ethernet1/1
  no cdp enable
  switchport mode dot1q-tunnel
  switchport access vlan 123
  spanning-tree bpdufilter enable
  l2protocol tunnel cdp

NX1# sh dot1q-tunnel 



Hello N.Sobin

Thanks for sharing that, it’s a good alternative to use to get the feature to work.

Thanks again!