08-28-2008 01:20 PM - edited 03-06-2019 01:03 AM
Some one else set this up, I'm trying to figure out why it was done this way. Seems a little excessive IMO.
There are currently 5 other switches connected with all vlans on them.
spanning-tree mode mst
spanning-tree portfast bpdufilter default
no spanning-tree optimize bpdu transmission
spanning-tree vlan 1,4-109,112-119,122-153,155-165,167-170,172 priority 16384
spanning-tree vlan 173-207,209-210,213-220,222,224-240,242-254 priority 16384
spanning-tree vlan 256-329,332-339,342-419,421-549,552-559,562 priority 16384
spanning-tree vlan 563-668,670-1000,2099-2100,2199-2200 priority 16384
spanning-tree vlan 2-3,111,121,154,166,208,211-212,221,223,241 priority 24576
spanning-tree vlan 255,331,341,420,551,561 priority 24576
spanning-tree vlan 110,120,171,330,340,550,560,669 priority 28672
!
spanning-tree mst configuration
name inf
revision 1
instance 1 vlan 110, 120, 171, 330, 340, 550, 560, 669
instance 2 vlan 2-3, 111, 121, 154, 166, 208, 211-212, 221, 223, 241, 255
instance 2 vlan 331, 341, 420, 551, 561
!
spanning-tree mst 0-1 priority 28672
spanning-tree mst 2 priority 24576
---Mike
08-28-2008 01:31 PM
Hi Mike,
As long as you are running in mst mode, all thee "spanning-tree vlan X priority Y" configuration lines are of no use for example. You can thus remove them and greatly reduce the size of your STP config.
It's hard to determine if they are really "excessive" though. They may be the legacy from a previous pvst config, and maybe the engineer who setup the MST config kept it in order to be able to fall back easily to pvst if necessary.
The "no spanning-tree optimize bpdu transmission" should not appear in the config. That's a bug. I'm amazed it's still showing up in recent releases. That's cosmetic anyway.
Regards,
Francois
08-29-2008 07:08 AM
Thanks Francois,
Are the three lines of no use since MST will carry all STP info for all vlan in the same BPDU's?
---Mike
08-29-2008 08:15 AM
Hi Mike,
Careful, I'm not talking about the three lines in the MST configuration submode. I'm talking about the seven lines specifying priority for the different vlan instances.
In pvst mode, you run one instance per vlan. So you have all the stp parameters instantiated by vlan. That's why you can set in particular the priority on a per vlan basis.
In mst mode, you only have up to 65 different instances. The priority of the different instances are set using a similar CLI, but with the mst keyword instead of vlan (spanning-tree mst x priority y).
My point was just that in mst mode, the vlan configuration is ignored (and in pvst mode, the mst configuration is ignored). So if you run mst, you can clean up the vlan configuration.
But again, be careful that the "instance X vlan Y" configuration lines are part of the vlan to instance mapping of mst. They are definitely relevant for the mst mode;-)
Regards,
Francois
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