Question : Setup a Tagged VLAN (802.1q) between Cisco 4ESW and 3Com 3C17203

Hi,

Am really struggling here....

I'm trying to set up a tagged VLAN (IEEE802.1q) between a Cisco 4ESW (4 port switch module) fitted to the back of a 1721 router and a a 3Com Superstack III 4400 (3C17203) switch.

I cannot get the traffic to route unless I make the VLAN untagged on the switch.

I do need it to be tagged though.

What do I need to do to get this working?

Do I need to set up a trunk? If so how can I do this?

Also can anyone help with the setup of VLAN on both the Cisco and the 3Com?

Here's my router config if it helps:

Current configuration : 984 bytes
!
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname TestNWRouter
!
enable secret 5 xxxxxxxxxxxxx
enable password xxxxxxxxx
!
no aaa new-model
ip subnet-zero
!
!
!
!
no ftp-server write-enable
!
!
!
!
interface FastEthernet0
 ip address 172.20.2.251 255.255.0.0
 speed 100
 full-duplex
!
interface FastEthernet1
 no ip address
 duplex full
 speed 100
!
interface FastEthernet2
 switchport access vlan 2
 switchport trunk native vlan 2
 switchport mode trunk
 no ip address
 duplex full
 speed 100
!
interface FastEthernet3
 no ip address
 shutdown
!
interface FastEthernet4
 no ip address
 shutdown
!
interface Vlan2
 ip address 10.80.12.254 255.255.0.0
!
interface Vlan1
 ip address 10.220.12.254 255.255.0.0
!
ip default-gateway 172.20.1.254
ip classless
ip route 0.0.0.0 0.0.0.0 172.20.1.254
!
ip http server
!
!
line con 0
line aux 0
line vty 0 4
 password xxxxxxxx
 login
!
!
end

Answer : Setup a Tagged VLAN (802.1q) between Cisco 4ESW and 3Com 3C17203

yvsupport,

By default all ports in 3Com switches belong to VLAN 1 (default VLAN). This VLAN is untagged. When you create VLAN 2 (tagged which is equal to 802.1q) and place some port into it the port belongs to both VLANs, 1 and 2. I don't distinctly remember if it's possible to remove the port from untagged VLAN in this case. If yes, do it and configure Cisco port the same manner. If not, you have to configure VLAN 1 untagged and VLAN 2 tagged on Cisco's port.

You have to create trunk or link aggregation on 3Com switch if you whant to combine 2, 3 or 4 ports into link.