How to config VLAN Trunking Port on Superstack II&III

[deepblue61]

My switch Superstack II 3300 and Superstack III 4400, I can't find anyway to config Trunk Port for VLAN. I'm going to use a Catalyst 3550 to connect superstack, there'll be a trunking port from Catalyst to 3com Switch. So thta's why I want to config a trunk port in Superstack.
Thanks for your help

 

[bkesting]

Open up a command line interface for your 3Com switch and enter the following command: "feature trunk portAdd"

You will then be prompted for a trunk index, enter 1 or 2 and then you will be prompted for what port(s) you want to place into the trunk.

I am trying to connect the same 3Com switch to a Catalyst 3524 via trunking. I got the connection established, but the addition of the Cisco switch brought my infrastructure down. Some type of loopback problem, I suspect it is with spanning-tree.

Hope this helps.

 

[deepblue61]

Hi, bkesting:


Thanks for your help!

Actually I'd like to ask you: if there's one trunking port from Catalyst 3550 connecting (output to)to 3com switch in Layer 2 level, do you think 3com superstack III switch can handle that? How can I configure it?
Thanks a lot!

 

[deepblue61]

I tried to configure VLAN Trunking port as you instructed, but when I telnet to switch, there's no option I can use to run "feature trunk portAdd" command, any idea?

Thanks!

 

[bkesting]

You may have to access the 3Com switch via its web interface. That seems to be the only way I know of to add 802.1q tagging to your trunk ports. Then it should be fairly easy from there to add a trunk port. Go into the VLAN setup and you should be able to add tagging to your port(s). Make sure your Cisco trunk is also using dot1q encapsulation on its trunk.

 

[deepblue61]

Hi, bkesting:

Thanks for your quick reponse!

Sorry to bother you again, I did find I can easily setup port trunk via "feature trunk portAdd". But according to 3com superstack II guide book, this port trunk concept is kind of different than Cisco vlan trunking. In 3com port trunking means you can communicate switches using up to 4 links in parallel in order to increase the bandwidth and run redundancy. But Cisco trunking means a port can forward multiple VLANs.
Any advise would be helpful, thanks!

 

[k12netguru]

Hi Deepblue.

You are correct. 3Com's trunking is adding additional ports in parallel to increase bandwidth. What Cisco calls trunking, 3Com calls port vlan tagging. What you will want to do is in the 3Com configure your uplink port to the Cisco with each vlan ID you have configured in the 3com and tag it regardless it is tagged or untagged on the individual ports. I ran into this difference in terminology a few months ago.

W

 

[abdulpmajeed]

Hai,

I am facing a problem like the one you are facing with slight difference. Actually, there are one cisco 2950 and two 3com 1100 switches are connected in a mesh. The connection between each 3com and cisco 2950 is established and it is working fine. But the connectivity between two 3 com is not established. With the spanning tree enabled, I have found that the spanning tree is working fine by blocking a port between two 3 com switches. When I shut down the link from cisco 2950 to a 3com, the link between 3com is not carrying traffic making the other 3 com users not accessible to the network.

The only difference is found in the stp cost and post cost between cisco and 3com switches for 100Mbps link.

Kindly guide me to make this link active
thanz in advance.

I have posted a fully explained question in this forum.


thanz in advance