how to confi backup link pr redundant link in ospf?

os73355

description *** Switch-1
ip address 10.10.10.1 255.255.255.252
!
outer ospf 1
log-adjacency-changes
redistribute static subnets route-map REDSTAT
passive-interface default
no passive-interface FastEthernet0/1
network 22.0.68.0 0.0.0.255 area 0
network 10.0.10.1 0.0.0.0 area 0
network 20.20.20.0 0.0.0.3 area 0
!
ip route 0.0.0.0 0.0.0.0 20.20.20.2
ip route 22.0.68.0 255.255.255.0 10.10.10.2
!
++++++++++++++++++++++++++++++++++++++++++++++
Headend (head office)
bgp 100
network 22.0.68.0 mask 255.255.255.0
++++++++++++++++++++++++++++++++++++++++++++++


=====================================================




CE Edge (20.20.20.17 255.255.255.252) - My router2
PE Edge (20.20.20.18 255.255.255.252)




Router2#int fa0/1
ip address 20.20.20.17 255.255.255.252
des connect to MPLS cloud


Router2#int fa0/1
ip address 10.10.10.5 255.255.255.252
des connect to Switch-1




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how to confi backup link pr rredundant link in ospf?