Hello Sathish
Looking at your configs everything looks like it should be working. I don’t see anything wrong. However, you can attempt to determine the state of the QinQ tunnel by using some of the verification commands included in the lesson such as:
SW1#show dot1q-tunnel
on both switchesSW1#show interfaces trunk
also on both switches to see what trunks have been configured and allowed
If you can also do a wireshark capture of the packets as they arrive on the switch to see their size and what kind of VLAN ID you see in the Ethernet frame, just to ensure that you get the expected results.
Finally, if you’re using GNS3, it may just be a problem with the images. Take a look at this GNS3 post:
https://gns3.com/getting-qinq-working-on-gns3
I don’t know if this has been resolved since this post (which is almost 4 years old) but it’s worth looking into.
I hope this has been helpful!
Laz