ip prefix-list
Configures an IP prefix list instance.
Syntax
ip prefix-list
name
{ [
deny
ip-prefix/prefix-length
|
permit
ip-prefix/prefix-length
]
ge
ge-value
[
le
le-value
]
]
|
seq
sequence-number }
Parameters
-
name
- Permitted values are between 1 and 32 characters. Although the first character must be alphabetic, the others can be alphanumeric, underscores (_) or minus signs (-).
-
deny
ip-prefix/prefix-length
- Denies a route specified in the prefix list.
The prefix list matches only on the specified prefix and prefix length,
unless you use the ge
ge-value or le
le-value parameters.
-
permit
ip-prefix/prefix-length
- Permits a route specified in the prefix list.
The prefix list matches only on the specified prefix and prefix length,
unless you use the ge
ge-value or le
le-value parameters.
- ge
ge-value
- Specifies the
minimum prefix length to be match. The range is from ge-value to 32.
- le
le-value
- Specifies the
maximum prefix length to be matched. The range is from the
le-value to the prefix-length parameter.
-
seq
sequence-number
- Specifies an IPv4 prefix list sequence
number. If you do not specify a sequence number, the software numbers them
in increments of 5, beginning with prefix list entry 5. The device
interprets the prefix list entries in numerical order, beginning with the
lowest sequence number.
Modes
Global configuration mode
Usage Guidelines
Enter no ip prefix-list name to
disable this feature.
The ge-value or
le-value you
specify must meet the following condition for prefix-length:
ge-value <= le-value <= 32
If you do not specify le-value ge
ge-value or
le
le-value, the
prefix list matches only on the exact prefix you specify with the ip-prefix/prefix-length parameter.
Examples
This example denies routes on
1.2.0.0/8, where the subnet mask length must be greater than or equal to 20 and
less than or equal to 28, and permits routes on 10.1.0.0/16.
device# config
device(config)#
device(config)# ip prefix-list test deny 10.0.0.0/8 ge 20 le 28
device(config)# ip prefix-list test permit 10.1.0.0/16
