[e-nsp] vlan trunk between summit 400 and cisco 3750

[Yu-lin CHANG (seawind)]

Hi Jonathan and all,

Thanks for all your help. The VLAN trunk between Summit400
and Cisco3750 is now working. What I did are,

1. on cisco3750
     interface g1/0/1
     switchport
     switchport trunk encap dot1q
     switchport mode trunk
     switchport trunk allow vlan 100,200
2. on Summit400
     config vlan v100 add port 1 tag
     config vlan v200 add port 1 tag
3. go back to cisco3750
     interface g1/0/1
     shutdown
     (wait few seconds)
     no shutdown

Then, the VLAN trunking works as expect.
BUT!!! another problem follows!!!

PCs on C3750 can now communicate with PCs on S400
without problem. But other cisco and summit switches
on S400 are now isolated!!!

I read some interface error messages on other cisco
switches (most of them are 2950) said they received
unexpected vlan-trunking information on a
non-vlan-trunking port.

 %SPANTREE-7-RECV_1Q_NON_TRUNK: Received 802.1Q BPDU
  on non trunk GigabitEthernet0/1 VLAN1.

 %SPANTREE-7-BLOCK_PORT_TYPE: Blocking GigabitEthernet0/1
  on VLAN0001. Inconsistent port type.

I don't know why S400 sends tunking information to those
"untagged" ports.

Finally, I have no choice to move all switch links from
"untagged" to "tagged" and config those 2950s GE uplinks
to VLAN trunking.

Does anyone has similar experience on this?

thanks and regards,
--
Yu-lin CHANG

---------------------------------------------
Jonathan Ruano wrote:
> Yu-lin,
> 
> I'm still getting acquainted to the Extreme swiches, but I'd check a
> couple of things:
> 
> a) Make sure ip forwarding is enabled on the summit (not sure if these
> switches have/need this.)
> 
> enable ipforwarding vlan "v100"
> 
> b) VLAN 100 should be created on the cisco (e.g, conf term, vlan 100,
> exit, exit)
> 
> You may want to see if you can see the Mac addresses of both devices on
> the switches.
> 
> Jon