4 area range – CANOGA PERKINS CanogaOS Command Reference User Manual

Page 243

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CanogaOS Command Line Reference

Revision 1.02

Proprietary & Confidential Canoga Pertkins Metro Ethernet Switches

Page 243 of 855

With this feature enabled in the “in” direction, all type 3 LSAs originated by the ABR to this area, based
on information from all other areas, are filtered by the prefix list. Type 3 LSAs that were originated as a
result of the area range command in another area are treated like any other type 3 LSA that was
originated individually. Any prefix that does not match an entry in the prefix list is implicitly denied.
With this feature enabled in the “out” direction, all type 3 LSAs advertised by the ABR, based on
information from this area to all other areas, are filtered by the prefix list. If the area range command
has been configured for this area, type 3 LSAs that correspond to the area range are sent to all other
areas, only if at least one prefix in the area range matches an entry in the prefix list.
If all specific prefixes are denied by the prefix list, type 3 LSAs that correspond to the area range
command will not be sent to any other area. Prefixes that are not permitted by the prefix list are
implicitly denied.


Examples

The following example filters prefixes that are sent from all other areas to area 1:
Switch(config-router)# area 1 filter-list prefix AREA_1 in


Related Commands

area range

15.4 area range

To consolidate and summarize routes at an area boundary, use the area range command in router
configuration mode. To disable this function, use the no form of this command.


Command Syntax

area area-id range { address mask | address/prefix-length} [advertise | not-advertise]
no area
area-id range {ip-address mask | ip-address/prefix-length}

area-id

Identifier of the area about which routes are to be summarized.

address

IPv4

address.

wildcard-mask

Mask for the associated IP subnet..

prefix-length

Prefix length of the address.

Default

This command is disabled by default.


Command Mode

Router configuration


Usage

The area range command is used only with Area Border Routers (ABRs). It is used to consolidate or
summarize routes for an area. The result is that a single summary route is advertised to other areas by
the ABR. Routing information is condensed at area boundaries. External to the area, a single route is

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