Brocade BigIron RX Series Configuration Guide - Manual (Page 867)

BigIron RX Series Configuration Guide 789
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Configuring OSPF
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Configuring an OSPF area prefix list
To filter prefixes advertised in type 3 link-state advertisements (LSAs) between (OSPF) areas of an
Area Border Router (ABR), use the area prefix-list command in router configuration mode. To
change or cancel the filter, use the no form of this command.
Configuring OSPF ABR type 3 LSA filtering
To filter inter-area routes into a specified area, use the following commands beginning in router
configuration mode.
To configure the router to run an OSPF process, enter commands such as the following.
BigIron RX(config)# router ospf
BigIron RX(config-ospf-router)#
To filter prefixes advertised in type 3 link-state advertisements (LSAs) between (OSPF) areas of an
Area Border Router (ABR), use the area prefix-list command in router configuration mode. To
change or cancel the filter, use the no form of this command.
BigIron RX(config-ospf-router)# area 1 prefix-list area in
To configure the switch to filter inter-area routes out of the specified area, enter a command such
as the following.
BigIron RX(config-ospf-router)# area 10.10.10.1 prefix-list Routesfor20 out
Syntax: [no] area {<area-id> | <area_ip>} prefix-list {prefix-list-name in | out}
The < prefix-list-name > parameter specifies the prefix list name.
The {<area-id> | <area_ip>} parameter specifies the area id in different formats.
The in keyword specifies that prefix list is applied to prefixes advertised to the specified area from
other areas.
The out keyword specifies that prefix list is applied to prefixes advertised out of the specified area
to other areas.
Defining and applying IP prefix lists
An IP prefix list specifies a list of networks. When you apply an IP prefix list to an area, the BigIron
RX sends or receives only a route whose destination is in the IP prefix list. The software interprets
the prefix lists in order, beginning with the lowest sequence number.
To configure an IP prefix list and apply it to an area, enter commands such as the following.
BigIron RX(config)# ip prefix-list Routesfor20 permit 20.20.0.0/24
BigIron RX(config)# router ospf
BigIron RX(config-ospf-router)#)# area 10.10.10.1 prefix-list Routesfor20 out
These commands configure an IP prefix list named Routesfor20, which permits routes to network
20.20.0.0/24. The area command configures the device to use IP prefix list Routesfor20 to
determine which routes to send to area 10.10.10.1. The device sends routes that go to 20.20.x.x to
area 10.10.10.1 because the IP prefix list explicitly permits these routes to be sent to the area.
Syntax: ip prefix-list <name> [seq <seq-value>] [description <string>] deny | permit
<network-addr>/<mask-bits> [ge <ge-value>] [le <le-value>]