pvst and mstp

carl_townshend · ‎05-16-2007

Hi all, i recently did a nortel course, from my cisco experience, am i right in saying that each vlan has its own instance of spanning tree (pvst), i have seen in nortel that you have to create seperate instances and apply them to each vlan, they define this as mstp, whereas in the cisco world this is slightly different, am i right here ?

tomesmyth · ‎05-16-2007

Hi Carl, don't know about the Nortel definitions but you are right about the Cisco ones. PVST is the Cisco default and this means that you can have different STP parameters per VLAN (root bridge, hello times etc). MSTP on Cisco is where you group several VLAN's together, the VLAN's in the group will have common parameters. You would do this if you have more VLAN's than your trunks can support or just to reduce the amount of BPDU's on your network.

Tom.