BFD
for Static Routes
To use BFD on a static route, both the firewall and
the peer at the opposite end of the static route must support BFD
sessions. A static route can have a BFD profile only if the Next
Hop type is IP Address.
If an interface is configured with more than one static route
to a peer (the BFD session has the same source IP address and same
destination IP address), a single BFD session automatically handles
the multiple static routes. This behavior reduces BFD sessions.
If the static routes have different BFD profiles, the profile with
the smallest Desired Minimum Tx Interval takes
effect.
In a deployment where you want to configure BFD for a static
route on a DHCP or PPPoE client interface, you must perform two
commits. Enabling BFD for a static route requires that the Next
Hop type must be IP Address.
But at the time of a DHCP or PPPoE interface commit, the interface
IP address and next hop IP address (default gateway) are unknown.
You must first enable a DHCP or PPPoE client for the interface,
perform a commit, and wait for the DHCP or PPPoE server to send
the firewall the client IP address and default gateway IP address.
Then you can configure the static route (using the default gateway
address of the DHCP or PPPoE client as the next hop), enable BFD, and
perform a second commit.