11-07-2012 06:17 AM - edited 11-07-2012 08:20 AM
I have a few Procurve 5412s running MST and firmware 15.08.0013. From what I can tell, it appears to be configured correctly, however when I run the command "show run" against those devices and compare it to my 3500yls the output is a bit strange. I have not set up multiple VLANs on the switch and am using VLAN 1 for everything until we finalize our new network designs. I am using instance 1 for MST instead of the default of 0.
It seems that when I plug a cable into a port on the 5412s the similar lines appear in my running config to those below. I do not see this behavior on my 3500yls. These ports are not uplinks to any other switch, just edge ports. I do have admin-edge-port set.
spanning-tree instance ist C8 path-cost 20000
spanning-tree instance ist L24 path-cost 200000
Is this normal behavior?
11-09-2012 02:42 AM
If you only have on vlan, there's not much point in using mstp, becuase the purpose of mstp is to use different path's for different vlans.
The path-costs are normal. These are the default path-costs based on the link-speed:
20 000= 1 gb
200 000= 100 mb
2 000 000=10mb
So if you do not configure it manually, the path-cost for a 1 gb link will be 20 000.
If you can explain why you want to use mstp and what it is you want to achieve it would be easier to help.
11-09-2012 12:55 PM
I am in the process of adding multiple VLANs to the network and will be setting up the full redundancy with VRRP so it will be needed here very soon. I know the port costs, but just wondering why they are showing up in my running config when I didn't set them. Is this something because I just have 1 VLAN at the moment or something with the 5412s?
11-12-2012 07:17 AM
It's because you have enabled MSTP. All links have path-cost, it's just a matter of using the default values or if you override them manually.
A link will always have a link-cost and if you don't set it manually, it will use the default values: