Routing – OSPF and VRRP Network Advertisements Explained

So, after working with JTAC yesterday, "I", as in I really didn't need JTAC since I figured out the issue on my own.. realized that my firewall filter was a bit redundant and was lacking a "permit any" statement.

OSPF adjacency was breaking because the firewall filter was taking the "else" traffic (term DEFAULT) and sending it to routing-instance PATH-2, which didn't help either way since it was sending traffic right back to SW-2, something a "then accept" statement would have done easily

So, to repair the issue..

New SW-2 & RTR-2 corrected configlets:

delete routing-instances PATH-2
delete firewall family inet filter FBF-TEST term DEFAULT
set firewall family inet filter FBF-TEST term PERMIT-ANY then accept

New config snips for SW-2:

routing-options {
    nonstop-routing;
    interface-routes {
        rib-group inet STAGING-RIB;
    }
    static {
        route 10.100.190.0/24 next-hop 10.100.100.2;
        route 10.100.191.0/24 next-hop 10.100.100.2;
    }
    rib-groups {
        STAGING-RIB {
            import-rib [ inet.0 PATH-1.inet.0 ];
        }
    }
    router-id 10.100.254.1;
}
firewall {
    family inet {
        filter FBF-TEST {
            term TERM-1 {
                from {
                    source-address {
                        10.100.190.0/24;
                        10.100.191.0/24;
                    }
                }
                then {
                    routing-instance PATH-1;
                }
            }
            term PERMIT-ANY {
                then accept;
            }
        }
    }
}
routing-instances {
    PATH-1 {
        instance-type forwarding;
        routing-options {
            static {
                route 10.100.30.0/24 {
                    next-hop 10.100.254.2;
                    qualified-next-hop 10.10.10.1 {
                        preference 100;
                    }
                }
            }
        }
    }
}

New config snips for RTR-2:

routing-options {
    interface-routes {
        rib-group inet STAGING-RIB;
    }
    rib-groups {
        STAGING-RIB {
            import-rib [ inet.0 PATH-1.inet.0 ];
        }
    }
    router-id 200.200.200.2;
    autonomous-system 1;
}
firewall {
    family inet {
        filter FBF-TEST {
            term TERM-1 {
                from {
                    source-address {
                        10.100.190.0/24;
                        10.100.191.0/24;
                    }
                }
                then {
                    routing-instance PATH-1;
                }
            }
            term PERMIT-ANY {
                then accept;
            }
        }
    }
}
routing-instances {
    PATH-1 {
        instance-type forwarding;
        routing-options {
            static {
                route 10.100.30.0/24 {
                    next-hop 200.200.200.1;
                    qualified-next-hop 10.100.254.1 {
                        preference 100;
                    }
                }
            }
        }
    }
}

Because you are telling R2 to originate the route. Upon origination the weight is set to 32768 as you can see, which beats the route from R1 which has a weight of 0. This allows R2 to advertise it back to R1 as it is R2's bestpath. If you remove the network statement on R2 it will receive the route as a BGP route via R1 only.

Check out the bestpath selection procedure for more info http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13753-25.html