Configuring Route Redistribution
If routinginformation must be exchanged among the different protocols or
routing domains, redistribution can be used. Only routes that are in the
routing table and learned via the specified protocol are redistributed. Each
protocol has some unique characteristics when redistributing, as shown in
Table 5-1.
Route Redistribution Characteristics
Protocol Redistribution Characteristics
RIP Metric must be set, except when redistributing
static or connected routes, which have a metric of 1.
OSPF Default metric is 20. Can specify the metric type;
the default is E2. Must use subnets keyword or only
classful networks are redistributed.
EIGRP Metric must be set, except when redistributing
static or connected routes, which get their metric
from the interface. Metric value is “bandwidth,
delay, reliability, load, MTU.” Redistributed routes
have a higher administrative distance than internal
ones.
IS-IS Default metric is 0. Can specify route level; default
is L2. Can choose to redistribute only external or
internal routes into IS- IS from OSPF and into
OSPF from IS-IS.
Static/Connected To include local networks not running the routing
protocol, you must redistribute connected inter
faces. You can also redistribute static routes into a
dynamic protocol.
You can redistribute only between protocols that use the same protocol
stack, such as IP protocols, which cannot advertise IPX routes. To configure
redistribution, issue this command under the routing process that is to
receive the new routes:
Router(config-router)#redistribute {route-source} [metric metric]
[route-map tag]