CCNP Switch : max # of root ports

Node Man

Hi Everyone,
Fact checking the book. What is the max number of root ports a catalyst switch can have? I think 1.


Thanks!

tomtom1

Node Man wrote: »

Hi Everyone,
Fact checking the book. What is the max number of root ports a catalyst switch can have? I think 1.
Thanks!

For a given instance of STP, there is 1 root port. So, when running common STP and common RSTP there is 1 root port, but when running PVST, VSTP (JunOS) or MST, you can have a root port per instance of STP.

Danielh22185

tomtom1 wrote: »

For a given instance of STP, there is 1 root port. So, when running common STP and common RSTP there is 1 root port, but when running PVST, VSTP (JunOS) or MST, you can have a root port per instance of STP.

And.. if considering PVST remember each vlan will by default run PVST so if you have 100 VLANS you could essentially have 100 Root Ports on a non-root switch.