before configuring a MSTP setup, I wanted to completely understand the MSTP example given in the Mikrotik Documentation here: https://help.mikrotik.com/docs/display/ ... STPexample.
However, I couldn't go through it without uncertainties: (See below for the diagram I'm learning on.)
mst-override interface ether3
I'm confused by the configuration on R1_3, R2_3, R3_3:
Code: Select all
/interface bridge port mst-override
add identifier=1 interface=ether2 internal-path-cost=5
add identifier=1 interface=ether3 internal-path-cost=9
Interface picking for VLAN groups
The documentation further states:
In this case for VLAN 10,20 to reach the third device from the first device, it would choose between ether1 and ether2, one port will be blocked and set as an alternate port, ether1 will have path cost as 5+9=14 and ether2 will have path cost as 10, ether2 will be elected as the root port for MSTI1 on the third device.
- "ether1 will have path cost as 5+9=14" - Is this derived from the forCode: Select all
mst-overrideconfigured on Rx_2 and Rx_3?Code: Select allidentifier=1 - If so, why will ether2 have path cost as 10 while ether2 on Rx_3 has a non-default configured path cost of 5? In either case, ether2 would be selected as root port, because for both cases path cost of 14 is higher.
Minor ambigous wording
We can either increase the port path cost or either decrease the port path cost to ports that are facing towards the regional root bridge.
If someone could help me understand this correctly, this would be awesome! Thanks
