Static routing

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Basics

Static routes, unlike those configured in through OSPF, BGP, or RIP must be configured manually by the router administrator. Because of this, it is recommended that static routing should only be used in small, simple networks. Configuring a static route will add the entry to the Routing Information Base, also known as the RIB. Because the RIB automatically removes rules that fail to connect, static routes may be removed from the routing table if they fail to properly route traffic.

Configuring Static IPv4 Routing

Static routes are manually configured network routes.

A typical use for a static route is a static default route for systems that do not make use of DHCP or dynamic routing protocols:

set protocols static route 0.0.0.0/0 next-hop 203.0.113.1 distance '1'

Producing the following configuration:

static {
    route 0.0.0.0/0 {
        next-hop 203.0.113.1 {
            distance 1
        }
    }
}

Another common use of static routes is to blackhole (drop) traffic. In the example below, RFC 1918 private IP networks are set as blackhole routes. This does not prevent networks within these segments from being used, since the most specific route is always used. It does, however, prevent traffic to unknown private networks from leaving the router. Commonly refereed to as leaking.

set protocols static route 10.0.0.0/8 blackhole distance '254'
set protocols static route 172.16.0.0/12 blackhole distance '254'
set protocols static route 192.168.0.0/16 blackhole distance '254'

Resulting configuration:

route 10.0.0.0/8 {
    blackhole {
        distance 254
    }
}
route 172.16.0.0/12 {
    blackhole {
        distance 254
    }
}
route 192.168.0.0/16 {
    blackhole {
        distance 254
    }
}

Note that routes with a distance of 255 are effectively disabled and not installed into the kernel.

Configuring Static IPv6 Routing