Administrator Guide
Layer 3 Routing Commands 1660
area range (Router OSPF)
Use the area range command in Router OSPF Configuration mode to
configure a summary prefix that an area border router advertises for a specific
area. There are two types of area ranges. An area range can be configured to
summarize intra-area routes. An ABR advertises the range rather than the
specific intra-area route as a type 3 summary LSA. Also, an area range can be
configured at the edge of an NSSA to summarize external routes reachable
within the NSSA. The range is advertised as a type 5 external LSA.
Use the no form of the command to delete an area range or revert an option
to its default.
Syntax
area area-id range prefix netmask {summarylink | nssaexternallink}
[advertise | not-advertise][cost cost]
no area area-id range prefix netmask {summarylink | nssaexternallink}
•
area-id
—
Identifies the OSPF NSSA to configure. (Range: IP address or decimal
from 0–4294967295)
•
prefix netmask
—
The summary prefix to be advertised when the ABR computes
a route to one or more networks within this prefix in this area.
•
summarylink
—
When this keyword is given, the area range is used when
summarizing prefixes advertised in type 3 summary LSAs.
•
nssaexternallink
—
When this keyword is given, the area range is used when
translating type 7 LSAs to type 5 LSAs.
•
advertise
—
[Optional] When this keyword is given, the summary prefix is
advertised when the area range is active. This is the default.
•
not-advertise
—
[Optional] When this keyword is given, neither the summary
prefix nor the contained prefixes are advertised when the area range is active.
Then the not-advertise option is given, any static cost previously configured is
removed from the system configuration.
•
cost
—
[Optional] If an optional cost is given, OSPF sets the metric field in the
summary LSA to the configured value, rather than setting the metric to the
largest cost among the networks covered by the area range. A static cost may only
be configured if the area range is configured to advertise the summary. The range
is 0 to 16,777,215. If the cost is set to 16,777,215 for type 3 summarization, a