Im going to base this off my VRF Setup and Route leaking article and continue building on top of it
Lets say we need to advertise connected routes within VRFs using IGP to an upstream or downstream iP address this is one of many ways to get to that objective
For this example we are going to use BGP to collect connected routes and advertise that over OSPF
Setup the BGP process to collect connected routes
router bgp 65000 router-id 10.252.250.6 ! address-family ipv4 unicast ! neighbor 10.252.250.1 ! vrf Tenant01_VRF ! address-family ipv4 unicast redistribute connected ! vrf Tenant02_VRF ! address-family ipv4 unicast redistribute connected ! vrf Tenant03_VRF ! address-family ipv4 unicast redistribute connected ! vrf Shared_VRF ! address-family ipv4 unicast redistribute connected
Setup OSPF to Redistribute the routes collected via BGP
router ospf 250 vrf Shared_VRF area 0.0.0.0 default-cost 0 redistribute bgp 65000
interface vlan250 mode L3 description OSPF_Routing no shutdown ip vrf forwarding Shared_VRF ip address 10.252.250.6/29 ip ospf 250 area 0.0.0.0 ip ospf mtu-ignore ip ospf priority 10
Testing and confirmation
Local OSPF Database
Remote device