Static routes are typically used in conjunction with dynamic routing protocols. You might configure a static route for a location that a dynamic routing protocol can’t reach. Static routes require manual configuration on every router in the network, rather than the firewall entering dynamic routes in its route tables; even though static routes require that configuration on all routers, they may be desirable in small networks rather than configuring a routing protocol.

If you decide that you want specific Layer 3 traffic to take a certain route without participating in IP routing protocols, you can Configure a Static Route using IPv4 and IPv6 routes.

A default route is a specific static route. If you don’t use dynamic routing to obtain a default route for your virtual router, you must configure a static default route. When the virtual router has an incoming packet and finds no match for the packet’s destination in its route table, the virtual router sends the packet to the default route. The default IPv4 route is 0.0.0.0/0; the default IPv6 route is ::/0. You can configure both an IPv4 and IPv6 default route.

Static routes themselves don’t change or adjust to changes in network environments, so traffic typically isn’t rerouted if a failure occurs along the route to a statically defined endpoint. However, you have options to back up static routes in the event of a problem:

By default, static routes have an administrative distance of 10. When the firewall has two or more routes to the same destination, it uses the route with the lowest administrative distance. By increasing the administrative distance of a static route to a value higher than a dynamic route, you can use the static route as a backup route if the dynamic route is unavailable.

While you’re configuring a static route, you can specify whether the firewall installs an IPv4 static route in the unicast or multicast route table (RIB), or both tables, or doesn’t install the route at all. For example, you could install an IPv4 static route in the multicast route table only, because you want only multicast traffic to use that route. This option give you more control over which route the traffic takes. You can specify whether the firewall installs an IPv6 static route in the unicast route table or not.