ip prefix-list
Configures an IP prefix list instance.
Syntax
ip prefix-list
name
seq
sequence-number
{
deny
ip-prefix/prefix-length
|
permit
ip-prefix/prefix-length
}
[
ge
ge-value
]
[
le
le-value
]
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. A name is also assigned to this configuration.
device# config
device(config)#
device(config)# ip prefix-list test deny 10.2.0.0/8 ge 20 le 28 description deny-internal-ip-range
device(config)# ip prefix-list test permit 10.1.0.0/16 description allow-internal-ip-range
