Hello,
I am assuming the blue router and the two green ones are all different.
If only one of the links (r1-s1 and r1-s2) is active at any given time then it would be easier to configure the blue router in ospf and redistribute from there.
Here are some disadvantages from redistributing the route from s1 and s2:
- You would have to depend on static routing.
- If for any reason the active interface (r1-s1 or r1-s2) looses connectivity but remains UP, then the static route would remain active and traffic would be blackholed.
If you add the blue router in ospf and redistribute from there:
- OSPF will take care of the routing when the connection changes from switch1 to switch2.
- OSPF hello's would also serve as a mechanism to detect failures in the link (automatic failover).
I hope this helps.