13: Static and Dynamic Routing

Static Routes

This topic is covered in more detail in JIR module 2.

All configuration happens at the ‘edit routing-options’ level of the configuration hierarchy. Static routes require a next hop. The egress interface or IP address of the next hop may be used. Packets can also be sent to the bitbucket. ‘reject’ sends an ICMP message for dropped packets, ‘discard’ drops packets silently.

Next hops identified by IP address must be directly connected. Junos does not do recursive lookups by default. To enable recursive next hop lookups, use the ‘resolve’ route option.

IPv6 static routes are configured in ‘rib inet6.0’.

rib inet6.0 {
    static {
        ...
    }
}

IPv4 static routes are configured simply under ‘static’.

static {
    route 0.0.0.0/0 next-hop 172.30.25.1;
    route 172.28.102.0/24 {
        next-hop ...
        no-readvertise;
        resolve;
    }
}

‘no-readvertise’ stops Junos advertising the route into dynamic routing protocols. Use this on management routes.

show route protocol static
ping ... rapid count 5

Floating static routes (Cisco terminology) can be configured using the ‘qualified-next-hop’ parameter.

static {
    route 172.28.102.0/24 {
        next-hop 172.30.25.1;
        qualified-next-hop 172.30.25.5 {
            preference 7;
        }
    }
}

Configuring OSPF

Enabling ‘passive’ on an interface prevents adjacencies being formed.

edit protocols ospf
show
area 0.0.0.0 {
    interface ge-0/0/1.0;
    interface ge-0/0/2.0;
    interface ge0/0/3.0 {
        passive;
    }
    interface lo0.0;
}

show ospf neighbor [detail/extensive]

show route protocol ospf

Routing Using IPv6

Enabling IPv6 automatically sets the interace’s link local IPv6 address and enables IPv6 processing on the interface.

set family inet6

The address can be configured explicitly.

set family inet6 address <xxxx::xxxx/n>

Most prefixes are /64. The best practice is to use /127 on point to point links . /128 for loopback addresses.

OSPF3 is effectively OSPF for IPv6. The fundamental mechanics of OSPF are unchanged. View OSPF3 neighbours;

show ospf3 neighbor