OSPF across two possible routes

RouterOS Forwarding Protocols
1

Dear Gentle Folk,

Running 4 mikrotiks 6.27 as follows

Mik A
/
Mik B MikC
\ /
Mik D
|
10.16.28.1/24

All four are announcing OSPF to each other.

Traffic to 10.16.28.0/24 comes from Mik A.

I need to control whether the traffic goes through B or C.

And I need to have a backup fail over from one to the other
if the used one goes down.

How is this done without static routes.

Thanks in advance,


Homer W. Smith
CEO Lightlink Internet

2

Make sure the cost metric is lower on the link you want to be the ‘backup’ link, and make sure it is lower on both ends of the link.

So lower the link metrics on A<>B and B<>D
This will become the primary path with the link via C being backup for A<>D.

This is set in Routing > OSPF > Interfaces

3

If you allow interface entries to be created dynamically in OSPF then you don’t get to control aspects of how the interface is configured for OSPF purposes. Creating a manual interface entry in OSPF allows you to set the path costs manually and also means that you can set the default interface entry to be “passive” which is good security practice since it is less likely that you will unknowingly start running OSPF on an interface without meaning to.