quote of the day... default route...

from odom, ocg ccnp route...

A router’s default route matches the destination of all packets that are not matched by any other route in the IP routing table. In fact, a default route can be thought of as the ultimate summary route–a route for the prefix that includes all IPv4 addresses, as represented by prefix/length 0.0.0.0/0.

jeff doyle in routing tcpip, calls it the exact same thing...

"the ulitmate summary route"

gateway of last resort, default route, ultimate summary route...

that works for me...

default network v default route...

is there a difference... according to below, the difference is propagation...

default network (per ocg)

An IOS mechanism for determining a router’s default route, by which the
router is configured with a classful network number as the default network, and the router uses its route for that network as its default route.

from 
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094374.shtml#route0.0

Use the ip default-gateway command when ip routing is disabled on a Cisco router. Use the ip default-network and ip route 0.0.0.0 0.0.0.0 commands to set the gateway of last resort on Cisco routers that have ip routing enabled. The way in which routing protocols propagate the default route information varies for each protocol.

this from
http://www.mcmcse.com/cisco/guides/ip_default_network.shtml
One point of confusion for some CCNA and CCNP candidates is the difference between configuring a static default route and using the Cisco routing command ip default-network.

At first glance, they appear to do the same thing. Both configure a destination to which packets should be routed if there is no more specific route in the routing table.

The major difference between these two options is that configuring a static default route only defines a default route for the router you're configuring it on, while ip default-network will propagate the route via its routing protocol.