Brocade Communications Systems Layer 3 Routing Configuration ICX 6650 - Manual (Page 262)

244 Brocade ICX 6650 Layer 3 Routing Configuration Guide
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OSPF V3 configuration
Administrative distance
The Brocade device can learn about networks from various protocols, including IPv6, RIPng, and
OSPF V3. Consequently, the routes to a network may differ depending on the protocol from which
the routes were learned. By default, the administrative distance for OSPF V3 routes is 110.
The device selects one route over another based on the source of the route information. To do so,
the device can use the administrative distances assigned to the sources. You can influence the
device decision by changing the default administrative distance for OSPF V3 routes.
Configuring administrative distance based on route type
You can configure a unique administrative distance for each type of OSPF V3 route. For example,
you can use this feature to influence the Brocade device to prefer a static route over an OSPF
inter-area route and to prefer OSPF intra-area routes to static routes.
The distance you specify influences the choice of routes when the device has multiple routes to the
same network from different protocols. The device prefers the route with the lower administrative
distance.
You can specify unique default administrative distances for the following OSPF V3 route types:
• Intra-area routes
• Inter-area routes
• External routes
The default for all of these OSPF V3 route types is 110.
NOTE
This feature does not influence the choice of routes within OSPF V3. For example, an OSPF intra-area
route is always preferred over an OSPF inter-area route, even if the intra-area route distance is
greater than the inter-area route distance.
For example, to change the default administrative distances for intra-area routes to 80, inter-area
routes to 90, and external routes to 100, enter the following commands.
Brocade(config-ospf6-router)#distance intra-area 80
Brocade(config-ospf6-router)#distance inter-area 90
Brocade(config-ospf6-router)#distance external 100
Syntax: distance external | inter-area | intra-area distance
The external | inter-area | intra-area keywords specify the route type for which you are changing
the default administrative distance.
The distance parameter specifies the new distance for the specified route type. You can specify a
value from 1–255.
To reset the administrative distance of a route type to its system default, enter the no form of this
command.