Re: bfd static routes and internet access

 OK, to simplify things I took 2 ER-8's here at my office and set them up just like your last example except that I had a PC connected to both routers, not just R2:

R2 === switch === R1 ----- Internet

The failover worked great for about the first 20 or so disconnects, and then notice what happened at R1.  Internet connectivity stopped working from R2 because the route out to R2 did not change when the primary link failed:

admin@R1# show interfaces
 ethernet eth0 {
     address 192.168.10.1/24
     description 10_LAN
     duplex auto
     speed auto
 }
 ethernet eth1 {
     address 192.168.110.1/24
     description "2GHz Link to R2"
     duplex auto
     speed auto
 }
 ethernet eth2 {
     address 192.168.111.1/24
     description "5GHz Link to R2"
     duplex auto
     speed auto
 }
 ethernet eth3 {
     duplex auto
     speed auto
 }
 ethernet eth4 {
     duplex auto
     speed auto
 }
 ethernet eth5 {
     duplex auto
     firewall {
         in {
             name GUEST_IN
         }
         local {
             name GUEST_LOCAL
         }
     }
     speed auto
 }
 ethernet eth6 {
     duplex auto
     speed auto
 }
 ethernet eth7 {
     address dhcp
     description TWC_Internet
     duplex auto
     firewall {
         in {
             name WAN_IN
         }
         local {
             name WAN_LOCAL
         }
     }
     speed auto
 }
 loopback lo {
 }
[edit]
admin@R1# show protocols
 bfd {
     interface eth1 {
         interval 500 {
             minrx 500 {
                 multiplier 3
             }
         }
     }
     interface eth2 {
         interval 500 {
             minrx 500 {
                 multiplier 3
             }
         }
     }
     interface eth3 {
         interval 500 {
             minrx 500 {
                 multiplier 3
             }
         }
     }
 }
 static {
     bfd {
         interface eth1 {
             ipv4
         }
         interface eth2 {
             ipv4
         }
     }
     route 192.168.20.0/24 {
         next-hop 192.168.110.2 {
         }
         next-hop 192.168.111.2 {
             distance 100
         }
     }
 }
[edit]
admin@R1:~$ show bfd session
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Remote-Addr
1          1            IPv4         Single-Hop  Admin-Down  00:00:00  192.168.110.2/32
2          2            IPv4         Single-Hop  Up          04:06:04  192.168.111.2/32
Number of Sessions:    2
admin@R1:~$ show ip route static
IP Route Table for VRF "default"
S    *> 0.0.0.0/0 [210/0] via 172.16.101.1, eth7
S    *> 192.168.20.0/24 [1/0] via 192.168.110.2, eth1 (recursive via 172.16.101.1 )
S       192.168.20.0/24 [100/0] via 192.168.111.2, eth2

However, R2 did properly make the route change:

admin@R2# show interfaces
 ethernet eth0 {
     address 192.168.20.1/24
     description 20_LAN
     duplex auto
     speed auto
 }
 ethernet eth1 {
     address 192.168.110.2/24
     description "2GHz Link to R1"
     duplex auto
     speed auto
 }
 ethernet eth2 {
     address 192.168.111.2/24
     description "5GHz Link to R1"
     duplex auto
     speed auto
 }
 ethernet eth3 {
     duplex auto
     speed auto
 }
 ethernet eth4 {
     duplex auto
     speed auto
 }
 ethernet eth5 {
     duplex auto
     speed auto
 }
 ethernet eth6 {
     duplex auto
     speed auto
 }
 ethernet eth7 {
     duplex auto
     speed auto
 }
 loopback lo {
 }
[edit]
admin@R2# show protocols
 bfd {
     interface eth1 {
         interval 500 {
             minrx 500 {
                 multiplier 3
             }
         }
     }
     interface eth2 {
         interval 500 {
             minrx 500 {
                 multiplier 3
             }
         }
     }
 }
 static {
     bfd {
         interface eth1 {
             ipv4
         }
         interface eth2 {
             ipv4
         }
     }
     route 0.0.0.0/0 {
         next-hop 192.168.110.1 {
         }
         next-hop 192.168.111.1 {
             distance 100
         }
     }
 }
[edit]
admin@R2:~$ show bfd session
Sess-Idx   Remote-Disc  Lower-Layer  Sess-Type   Sess-State  UP-Time   Remote-Addr
1          1            IPv4         Single-Hop  Admin-Down  00:00:00  192.168.110.1/32
2          2            IPv4         Single-Hop  Up          04:08:53  192.168.111.1/32
Number of Sessions:    2
admin@R2:~$ show ip route static
IP Route Table for VRF "default"
S    *> 0.0.0.0/0 [100/0] via 192.168.111.1, eth2
S       0.0.0.0/0 [1/0] via 192.168.110.1 inactive

Again, please point out what I'm doing wrong in my configuration.  That's why I continue to include it.  I'm also more than happy to upload my complete config if that will help. If you don't think there is a bug in BFD, please help me determine what I am doing wrong.  The key here is that it takes multiple (>20) disconnects of the primary link before the behavior starts to occur for me.

Thanks again!

Will