Redistributing Routing Information from Other Domains
RIP can be configured to import external routing information from other routing
domains (that is, protocols or static routes) into the autonomous system.
Command Attributes
• Redistribute Protocol – Only static routes can be imported into this routing
domain.
•
Redistribute Metric
– Metric value assigned to all external routes for the specified
protocol. (Range: 1-15; Default: The default metric value is set by the
default-metric
command described on page 42-7).
If a redistribution metric has not been configured for static routes, the
default-metric
command (page 42-7) sets the metric value to be used for all
imported external routes.
A route metric must be used to resolve the problem of redistributing external routes
with incompatible metrics.
It is advisable to use a low metric when redistributing rout es f ro m an ot her pr otoco l
into RIP. Using a high metric limits the usefulness of external routes redistribu ted
into RIP. For example, if a metric of 10 is defined for redistributed rout es, these
routes can only be advertised to route rs up to 5 hops aw ay, at w hich point th e
metric exceeds the maximum hop count of 15. By defining a low metric o f 1, traf fic
can follow a imported route the maximum numb er of hop s allow ed within a RIP
domain. However, using a low metric can increase the possibility of routing loops
For example, this can occur if there are multiple redistribution points and the router
learns about the same external network with a better metric from a redistribution
point other than that derived from the original sour ce.

20-9

Configuring the Routing Information Protocol

20