2 x 4200G and VLANS with a 3rd Party Switch

[eblok2001]

Hello Guys,

I´m coming from Cisco environment and have  not so much experience with 3Com Switches .

I have a new customer , we have  build up 2 x 4200G Switch in an VMWARE Environment .

I made a VLAN20 on every 4200G and set 10 Ports on every Switch to Access --- >> untaged VLAN20

i have connectet the switches direct via a patch kabel and set these ports on every switch as

Trunk --- > Taged VLAN 20

Now comes my question :-)

The Main Switch below the two 3COM Devices  is a poor L2  Linksys ( but it is so... has FX Connections :-(  )

and i want to connect every 3COM with one cable to the linksys .. due to redundant connections.

After this , I have conectet every 3com with one cable to the linksys, and the 3coms also direct connectet 

 between the switches.

It is a kind of loop  i think , and i´m afraid vlan1 packages are running on a circle between the switches

and bring them to burn ...  ??  ( Broadcast Storm )

In normal way I would assign the VLAN Ports only to it´s own VLAN but on the 3COM GUI i could not kill

the standard VLAN 1 on the VLAN 20 Ports

Is is possible to configure the direct connection between the switches to pass only the VLAN tagged traffic ?

or will the vlan1 untagged traffic also go over this bridgde ??

Or does the 3COM have default RSTP ( Spanning tree ) enabeld .. so that such things cannot happen ?

Regards , and thx for some tips.

Christian from Germany