what is the different between a candidate default route and gateway of last resort

hitmen

I am referring to ccnp route ocg pg 130

tomtom1

A candidate default route is a prefix that can be used as a default route, but doesn't have to. With a gateway of last resort, mainly used with the ip default-network command you set a network and a next-hop router as a last resort (default gateway). As you can see in the OCG, the I1 router has a candidate default route to network 192.31.7.0/24 because of the ip default-network 192.31.7.0 (mind the classful nature).

By advertising the candidate default 192.31.7.0 0.0.0.255 network in EIGRP AS 1 other EIGRP routers in AS 1 see the network as a candidate default, and can have this network set as a gateway of last resort. Because the 192.31.7.0/24 prefix is the only candidate default in the IP routing table of B1, it set's the gateway of last resort to the next hop for the 192.31.7.0/24 prefix, which is L1's interface.

So they really work together in providing a default route.