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Cisco Nexus 3548 Switch NX-OS Unicast Routing Command Reference
OL-27852-01
Chapter Unicast Routing Commands
ip prefix-list
ip prefix-list
To create a prefix list to match IP packets or routes against, use the
ip prefix-list
command. To remove
the prefix-list, use the
no
form of this command.
ip prefix-list
name
[
seq
number
] {
permit
|
deny
}
prefix
[
eq
length
| [
ge
length
] [
le
length
]]
no prefix-list
name
[
seq
number
] {
permit
|
deny
}
prefix
[
eq
length
| [
ge
length
] [
le
length
]]
Syntax Description
Command Default
None
Command Modes
Global configuration mode
Command History
Usage Guidelines
You configure prefix lists with
permit
or
deny
keywords to either permit or deny the prefix based on the
matching condition. A prefix list consists of an IP address and a bit mask. The bit mask is entered as a
number from 1 to 32. An implicit deny is applied to traffic that does not match any prefix-list entry.
You can configure prefix lists to match an exact prefix length or a prefix range. Use the
ge
and
le
keywords to specify a range of the prefix lengths to match, which provides a more flexible configuration.
If you do not configure a sequence number, Cisco NX-OS applies a a default sequence number of 5 to
the prefix list and subsequent prefix list entries are incremented by 5 (for example, 5, 10, 15, and so on).
If you configure a sequence number for the first prefix list entry but not subsequent entries, then Cisco
NX-OS increments the subsequent entries by 5 (for example, if the first configured sequence number is
3, then subsequent entries will be 8, 13, 18, and so on). You can suppress default sequence numbers by
entering the
no
form of this command with the
seq
keyword.
Cisco NX-OS evaluates prefix lists that start with the lowest sequence number and continue down the
list until a match is made. Once a match is made, the
permit
or
deny
statement is applied to that network
and the rest of the list is not evaluated.
name
IP prefix list name. The name can be any alphanumeric string up to 63 characters.
seq
number
(Optional) Specifies the number to order entries in the prefix list. The range is
from 1 to 4294967294.
permit
Allows routes or IP packets that match the prefix list.
deny
Rejects routes or IP packets that match the prefix list.
prefix
IP prefix in A.B.C.D/length format.
eq
length
(Optional) Specifies the prefix length to match. The range is from 1 to 32.
ge
length
(Optional) Specifies the prefix length to match. The range is from 1 to 32.
le
length
(Optional) Specifies the prefix length to match. The range is from 1 to 32.
Release
Modification
5.0(3)A1(1)
This command was introduced.
