System information

Configuring OSPF
11-17
Changing OSPF Administrative Distances
The administrative distance number between 0 and 255 rates the credibility of routing
information from one or more routers. A routing source assigned a low administrative
distance is trusted more than a routing source that is assigned a high administrative
distance value.
The default administrative distance for inter-area and intra-area OSPF routes, and
external routes is 110. Use either the following options to set the administrative
distance for OSPF routes:
• To set all three OSPF distances to the same value, use the distance command in
Router Configuration mode, as shown below:
MOT(config-ospf)#distance <distance>
where:
distance is the administrative distance; valid values are from 1 to 255.
Routes within an OSPF area are intra-area; routes to another OSPF area are inter-area;
and routes from another routing domain learned through the redistribution of a route
have an external designation.
• Use the distance ospf command in Router Configuration mode to set an
individual value for the administrative distance value for an intra-area OSPF
route, inter-area OSPF Route, and external route, as shown below:
MOT(config-ospf)#distance ospf intra-area <distance> inter-area
<distance> external <distance>
where:
intra-area <distance> represents the administrative distance number from 1
to 255 for all routes within an area.
Note: If the assigned administrative distance for a routing source is 255, it is
not trusted and is ignored.