SMC Networks WPCI-G - annexe 1, Руководство по управлению

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IP R
OUTING
C
OMMANDS
37-10
Command Usage
• This command does not override the metric value set by the
redistribute command (see page 37-15). When a metric value has not
been configured by the redistribute command, the default-metric
command sets the metric value to be used for all imported external
routes.
• The default 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 routes from
another protocol into RIP. Using a high metric limits the usefulness of
external routes redistributed into RIP. For example, if a metric of 10
is defined for redistributed routes, these routes can only be advertised
to routers up to 5 hops away, at which point the metric exceeds the
maximum hop count of 15. By defining a low metric of 1, traffic can
follow a imported route the maximum number of hops allowed within
a RIP domain. However, note that 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 source.
Example
This example sets the default metric to 5.
Related Commands
redistribute (37-15)
Console(config-router)#default-metric 5
Console(config-router)#