Pvst and ISL
Hi,
Im reviewing the BCMSN guide, and it states that PVST (without +) can only run trunks with ISL. However on my home lab i have dot1q trunks running with pvst. Is it actually using pvst+ then?
Thanks ppl.
Im reviewing the BCMSN guide, and it states that PVST (without +) can only run trunks with ISL. However on my home lab i have dot1q trunks running with pvst. Is it actually using pvst+ then?
Thanks ppl.
Studying for CCNP (All done)
Comments
kpjungle,
Here's some official documentation from Cisco...
The indirect point that Cisco wants to make is how PVST and PVST+ are better than CST. What is CST?
So in summary (indirect BSCI joke attempt) with CST, the root bridge is the same for all VLANs. The weakness in this design is if the CST root bridge device goes down, there's going to be a new STP re-election for a new root bridge which may become a major disruption for all other switches and hosts in the LAN, since all VLANs are affected. However, PVST and PVST+ both reduce the STP re-election for root bridge disruption because the unaffected VLANs are left alone in their current stable and converged state and only the affected VLANs are involved in the PVST or PVST+ root bridge re-election. Does this help understand PVST and PVST+ better?
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