After adding some network adaptor (DUB-E100) on my server to make the trunk available for my 3 sites , DOT1Q was not able to work on the config …. Damned I figured out at this point that I could pass my vlan over this link .

After more troubleshooting and thinking, I came to the point to enable ISL instead of DOT1Q , and after this my trunk was really up and useful as it passed now the vlan information ….. woohoo .

Can continue right now on implementation ….

🙂