When configuring a static route on point-to-point networks, an alternative to using the next-hop IPv6 address is to specify the exit interface. This is an alternative used in older IOSs or whenever CEF is disabled, to avoid the recursive lookup problem.

For instance, in Figure 1, three directly connected static routes are configured on R1 using the exit interface.

The IPv6 routing table for R1 in Figure 2 shows that when a packet is destined for the 2001:DB8:ACAD:3::/64 network, R1 looks for a match in the routing table and finds that it can forward the packet out of its Serial 0/0/0 interface. No other lookups are required.

Notice how the routing table looks different for the route configured with an exit interface than the route configured with a recursive entry.

Configuring a directly connected static route with an exit interface allows the routing table to resolve the exit interface in a single search instead of two searches. Recall that with the use of the CEF forwarding mechanism, static routes with an exit interface are considered unnecessary. A single lookup is performed using a combination of the FIB and adjacency table stored in the data plane.

Use the Syntax Checker in Figure 3 and Figure 4 to configure directly connected static IPv6 routes.