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Cisco Switches mxied with 3Com

I have 3 Catalyst 3500's on one IP subnet. All users on the switches are in the default VLAN1. I am in need of another switch and am being sent a 3com by headquarters. My question is this: How will the Cataylst switches and the 3com work together? Will this affect spanning tree?



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Re: Cisco Switches mxied with 3Com

they should work fine together. If you are not using vlans then there is no problem. If you are then the 3com and Cisco switch should both use 802.1q. I have Cisco and Cabletron working just fine.

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Re: Cisco Switches mxied with 3Com

OK... thanks for the quick response. The industry standard is 802.1d, correct? So, If I'm running .q on the cat's, will I need to change this?

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Re: Cisco Switches mxied with 3Com

802.1d is the industry standard for Spanning-Tree. Your previous question was concerning if 3com and Cisco would play fine together, well they should but if you are doing any VLANS just make sure 3com trunks / Cisco trunks are set up for Dot1.q encapsulation (for vlans).



Re: Cisco Switches mxied with 3Com

Keep in mind that if you start doing VLANs on the Cisco side, that you will have a Spanning Tree per VLAN (PVST+). 3Com only does Spanning Tree at the switch level, on VLAN 1. So if you have to implement your redundant connection through the 3Com switch, this complicates matters.

If you keep the 3Com switch single-connected, then 802.1q trunk to it, it'll work fine. Let the Ciscos handle the redundancy, they're more flexible.

Also keep in mind that whereas VTP automates VLAN management somewhat on Cisco switches, on the 3Coms you must define each VLAN and associated 802.1q tag on each switch.

And assigning ports to VLANs is done in two places in the 3Com GUI: one place handles 802.1q tagged ports; the other handles untagged VLAN assignment per port. A little confusing and tedious, but doable...

Hope this helps.

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