Multi-Vlans trunking between 3500XL & 3300

[bsomali]

Hi,

I have browsed through this forum and tried a few of relevant suggestions, but I couldn't get it worked the way I want.

Configurations are:

Cisco 3550 L3 <--trunk--> Cisco 3500XL <---> 3Com 3300

|

<--trunk--> Cisco 3500XL <---> 3Com 3300

3550 has dot1q trunking to 2 3500XL and multi-Vlans worked on each 3500XL.

How do I configure 3500XL and 3Com to make multi-Vlans working on each 3300 as well?

For example:

1. 3550 has 3 Vlans, ie. Vlan1 (default) Vlan 11 and Vlan 22

2. All switches have management IP on Vlan 1 (10.1.1.x/24)

3. Vlan 11 IP: 10.1.2.0/24 and Vlan 22 IP: 10.1.3.x/24

4. Ports on each 3500XL can be individually assigned to Vlan 11 or Vlan 22 and working.

5. But for each 3300, I can only make one VLAN working.

Appreciate any suggestion or assistance.

[tsettle]

The 3300 supports dot1q trunking too doesn't it? Configure a trunk between the XL and 3300. Make sure the native vlan is untagged on the 3300 and that it matches that of the XL (default for both is vlan 1). If there is an issue with tagging the native then simply create a dummy native vlan on XL.

http://support.3com.com/infodeli/tools/switches/s_stack2/1695/manual.a01/manage.pdf

[bsomali]

Thanks for your replies, Prabakhar and Thomas.

I did the following:

1. Port 24 in 3500XL: trunk encap dot1q, native Vlan 1, allowed Vlan 1 & 11

2. In 3500XL, create Vlan 11 interface with the helper-address for different IP scope

3. Port 12 in 3Com 3300 uplinking to 3500XL: Vlan 1 untagged, Vlan 11 tagged dot1q

4. Port 1 in 3Com for client: Vlan 1 untagged, Vlan 11 tagged dot1q

5. Ip release and renew from client didn't get IP from the Vlan 11 scope, but from default Vlan 1.

What's missing or wrong?

By the way, how does it work for you, Prabakhar?

[preddyi · Accepted solution]

Here you said port 1 of 3300 is connected to Pc.

port one you have configured as trunk.

Does that PC's NIC card support trunking?

If not keep port 1 in VLAN 11 untaged.(access port)

[bsomali]

Great, it worked now.

The key is that by tagging dot1q to a port in 3Com, it becomes a trunk to Cisco. Then other ports should be untagged on desired Vlan.

Thanks so much, Prabakhar.

[preddyi]

Cisco 3500XL <--trunk-> 3Com 3300

you might have configured the port in 3550XL connecting to 3300 as trunk port and DOT1q Tagging.

As 3COM Swithces support only 802.1Q tagging,

At 3300 You nee to configure the port uplinking to 3550XL with 802.1q Tagging enabled.

I have tested this simillar set up with

Intel550T stack (VLAN100,101,102,103)<---802.1Q Trunk-->3300 Stack (VLAN100,102,103)

It works fine.