3com to Cisco

[wilson2468]

If I am creating a trunk for VLAN traffice from 3com to Cisco my understanding is this:

Say I left VLAN 1 for management, and had VLAN2 and VLAN3 also


Trunk ports:
1. Native vlan should be untagged on both ends.
2. All other VLANs should be tagged.

All ports assigned to the differnt VLANs should be untagged.

Is this correct?

 

[SYQUEST]

I recently built a VLAN between a 3COM 3C16475 switch and a Cisco C2950G-24EI switch using a mini-GBIC to GBIC. The setup used ports 23 & 24 as D for desktop and port 26 as U for uplink in VLAN 2. No tagging was done. So far it has been working OK. On the Cisco end, it was much more envolved because of all the options available. I had originally posted on the Cisco Router Forum and used the responses as a rough outline and went thru the Cisco documentation to figure out what needed to be programmed.

It worked the first time when I tested the setup in the same room. The only hiccup I had was when I unplugged the 3COM to install it in its home location. When everything was powered up I had no continuity on VLAN 2. I tried some things, but nothing worked. So I deleted the VLAN 2 in the 3COM and built it back and it started working. I don't know why and haven't found an answer yet, but it's still working.

The "tagging" part is still not clear to me, but was told for this setup it was not needed.

Hope this helps!

....JIM....

 

[wilson2468]

What is the procedure for:

1. setting the native vlan
2. assigning the ports to the tagged trunk port

I can't seem to find any clear information on how this should be set up on the trunk port to the Cisco device

 

[IRudebwoy]

Q2 Answer: Tagged ports can members of multiple VLANs. While untagged ports can be a member of only one VLAN. Therefore, you should assign ports as untagged when connecting to your desktops or servers and tagged when connecting inter-switch links that carry multiple VLAN traffic. Furthermore, your inter-switch links should be an untagged member of the default VLAN for management access to down-stream switches.

Q1 Answer: Depending on the switch you can set the default VLAN other than VLAN_ID 1. It can be very easy or on par with a root canal. So I tend to leave the default VLAN as ID 1 and build around it, so I can manage the switches without too much trouble.

Have Fun!

 

[wilson2468]

But is there a step by step instruction on how to do it?

When I have an HTTP connection, it is not clear on how to set it.

It only allows adding the ports if they are tragged, it also loos like all ports are member of vlan 1.

You cannot remove ports from vlan 1 unless they are tagged.

When you tag the ports, they still shou up as untagged in vlan 1.

It doesn't make sense to me the way the ports can only be a member of another

 

[SYQUEST]

Hi wilson2468,

What 3COM switch are you using?

Do you have 3COM documentation for it?

When I set mine up I just read the manual and set the options. The setup on the 3C16475BS is done by a GUI. It was very simple compared to the Cisco. But the 3COM manual could use more details and explanations.

....JIM....