number of MSTP instances needed

[Sherif Atef Ahmed Ismail]

Dears,

I have a query about MSTP instances number and would like your advise plz

If access switch [A] has 400 VLANs and it connected to two distribution switches B & C

Now we have have 2 possible STP topologies thus 2 instances are needed

My question now, what is the recommnended to configure from below & why ?

1- Configure only 1 instance so now you 2 instances ; instance 0 and instance 1

or

2- Configure 2 instances so now you have 3 instances; instance 1 & instance 2 beside instance 0

Many Thanks

BR,

Sherif Ismail

[Joseph W. Doherty]

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