[c-nsp] dot1q-tunneling

[Boštjan Fele]

Been a while since I worked with Extreme switches.. 

If Cisco is doing Q-in-Q then Extreme is droping frames. Extreme does not expect Q-IN-Q with 0x8100 ethertype. It is a sort of security feature to prevent VLAN hopping, but check with Extreme gurus...

Regards,
Bostjan

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Alex Cruz Farmer
Sent: Wednesday, August 02, 2006 6:37 PM
To: cisco-nsp at puck.nether.net
Subject: [c-nsp] dot1q-tunneling

Hi,

I've currently got two 3750s in two locations with an interlink inbetween using Extreme switches. 
Currently, the configuration seems to be fine:

interface GigabitEthernet1/0/24
  switchport access vlan 544
  switchport mode dot1q-tunnel
  duplex full
  speed 100
  no cdp enable
end

then...

interface GigabitEthernet1/0/18
  switchport access vlan 544
  switchport mode dot1q-tunnel
  duplex full
  speed 100
  no cdp enable
end

The Extreme config is super simple, the ports are untagged on Vlan 544 on the 3750 ends, then tagged on the uplink ports between the two extreme switches at each site. Jumbo frames *is* enabled on the Extreme switches (9216).

Both Ciscos have the following MTU settings:

System MTU size is 1546 bytes
System Jumbo MTU size is 1546 bytes

I can't see what could be wrong, as from what I've read simply trunking the Vlan should work, although, there is a change of Vendor inbetween... If anyone has any suggestions that would be much appreciated. These switches aren't currently live, so settings can be changed. :)

Kind regards,

Alex.
_______________________________________________
cisco-nsp mailing list  cisco-nsp at puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp
archive at http://puck.nether.net/pipermail/cisco-nsp/