Switching

I am wondering if there is a fast way to switch from VSTP to MST on a Juniper.

I am currently using VSTP and I am trying to switch to MST.

I have the MST configuration in place as inactive.

So when I go to swap protocols, I can just issue:

activate protocols mst

deactivate protocols vstp.

However when I attempt to commit, it says that another STP protocol is running.

Any suggestions?

Delete vstp activate mstp. You can allways rollback to vstp when nessecary.

If I issuethe following:

delete protocols vstp

 commit check

It has the same error, that it cannot activate MST because another STP is running.

I am trying to avoid the following:

inactivate protocols vstp

commit

activate protocols mst

commit

I am hoping to do it in a single commit to limit impact.

And rstp is disabled? That's enabled by default config.

It was RSTP. It only had the one line so I was overlooking it.

Ran the following which worked fine:

delete protocols rstp

deactivate protocols vstp

activate protocols mstp

commit

Thanks!

Also my Cisco/Juniper/Dell PVSTP/VSTP  to MST conversion went well.

Only major gotcha was that my Cisco's are running older code, so they are pre-standard MST. 

So right now I have dual Regions (Cisco and everthing else), but luckily I am migrating off the Cisco in the next month.

Made sure that management was aware of the failure mode and L2 traffic flow implications, and I am good to go.

Lots of pre-planning required. Different vendors have different number of vlans, how to name each MST instance, etc.

So for a Cisco/Juniper/Dell network I went with:

set protocols mstp configuration-name ewc-mst
set protocols mstp revision-level 2
set protocols mstp bridge-priority 40k
set protocols mstp msti 1 vlan 1-125
set protocols mstp msti 2 vlan 126-250
set protocols mstp msti 3 vlan 251-375
set protocols mstp msti 4 vlan 376-500
set protocols mstp msti 5 vlan 501-625
set protocols mstp msti 6 vlan 626-750
set protocols mstp msti 7 vlan 751-875
set protocols mstp msti 8 vlan 876-1000
set protocols mstp msti 9 vlan 1001-1500
set protocols mstp msti 10 vlan 1501-2000
set protocols mstp msti 11 vlan 2001-2500
set protocols mstp msti 12 vlan 2501-3000
set protocols mstp msti 13 vlan 3001-3500
set protocols mstp msti 14 vlan 3501-4000
set protocols mstp msti 15 vlan 4001-4093

 Dell has the most formal structure in regards to MST which drove the design of the region:

1. Only Supports MST instances named 1-15  (Cisco and Dell can do 4000 or such)
2. Only supports up to vlan 4093 (Cisco is 4095, Juniper 4094)

I premapped the vlans to instances to avoid any changes in the future to the region config.

We should be good for quite awhile.