difference between 802.1d stp and cst

[sarahr202]

hi every body!

I am just confused about the difference between 802.1d stp and cst. Are they same?

thanks a lot!

[Jon Marshall · Accepted solution]

Sarah

802.1d is the IEEE spanning-tree algorithm that prevents loops in a layer 2 network.

CST is an implmentation of 802.1d where there is only one instance of STP running for all the vlans in your layer 2 network no matter how many vlans that is.

PVST/PVST+ is an implementation of 802.1d where each vlan runs it's own instance of STP.

Jon