The reason for MST is that we have HP switches on our network along with Cisco. MST we found works best for interoperability between them (HP has a good document on this as well). The two core switches also handle all routing so if one dies the other takes over. Each wiring closet has two fiber links, one back to Switch 1 and the other to Switch 2 again for redundancy. I will not have any control over the client's switch so configuring an MST instance there can't happen. I guess I am just wondering if there is a simple way to protect my equipment from theirs and still allow them access to my VoIP VLAN. I don't necessarily have to give them a trunk port if there are other methods that are safer and can allow their phones to access the same subnet. My closet switches are 2950-48s with 2 fiber uplinks each.
From what I had been reading Root Guard may help (but I am not 100% sure). Basically the client should be able to set up their own STP if they want and set the root bridge to whatever. I think that I can set root guard on the access ports that I designate to them this way they cannot compromise my access switch and can run their network however they choose. Am I correct in saying this?
