[c-nsp] Sorta OT: Cisco, trunks, VLANs, and the 3com Intellijack

[nick hatch]

Hi all,

I'm having some interoperability issues with VLAN trunks (802.1q) between
Cisco and 3Com devices.

Our building is short on horizontal runs, so we have a few 3Com Intellijacks
(NJ2000, NJ220) we'd like to use for our network admins. The idea is to
bring a few VLANs out to each switch, and break them out there. (eg, Port 1
could be for normal access, Port 2 could be on a RSPAN VLAN, etc)

I thought it would be simple, but I'm having a really difficult
time deciphering the management interface on the 3Com. My usual pattern is
to try something (eg different native vlan), lock myself out of the device,
roll back the changes, wash-rinse-repeat.

Some research seems to indicate that Cisco and 3Com have differing
philosophies on trunk ports and vlan tagging [1][2], but I've been unable to
track down what I'm doing wrong and find a working recipe.

Any help or advice would be greatly appreciated.

-Nick

[1]
http://devroot.org/2007/02/25/trunking-between-a-cisco-catalyst-and-a-3com-superstack/
[2] http://www.velocityreviews.com/forums/t40372-3com-vlan-help.html