Users Guide

If you are creating a standard prefix list with only one or two filters, you can let the system assign a sequence number based on the order
in which the filters are configured. The system assigns filters in multiples of five.
Creating a Prefix List Without a Sequence Number
To create a filter without a specified sequence number, use the following commands.
1 Create a prefix list and assign it a unique name.
CONFIGURATION mode
ip prefix-list prefix-name
2 Create a prefix list filter with a deny or permit action.
CONFIG-NPREFIXL mode
{deny | permit} ip-prefix [ge min-prefix-length] [le max-prefix-length]
The optional parameters are:
• ge min-prefix-length: is the minimum prefix length to be matched (0 to 32).
• le max-prefix-length: is the maximum prefix length to be matched (0 to 32).
Example of Creating a Filter with System-Assigned Sequence Numbers
The example shows a prefix list in which the sequence numbers were assigned by the software. The filters were assigned sequence
numbers based on the order in which they were configured (for example, the first filter was given the lowest sequence number). The
show config command in PREFIX LIST mode displays the two filters with the sequence numbers 5 and 10.
Dell(conf-nprefixl)#permit 123.23.0.0 /16
Dell(conf-nprefixl)#deny 133.24.56.0 /8
Dell(conf-nprefixl)#show conf
!
ip prefix-list awe
seq 5 permit 123.23.0.0/16
seq 10 deny 133.0.0.0/8
Dell(conf-nprefixl)#
To delete a filter, enter the show config command in PREFIX LIST mode and locate the sequence number of the filter you want to
delete, then use the no seq sequence-number command in PREFIX LIST mode.
Viewing Prefix Lists
To view all configured prefix lists, use the following commands.
• Show detailed information about configured prefix lists.
EXEC Privilege mode
show ip prefix-list detail [prefix-name]
• Show a table of summarized information about configured Prefix lists.
EXEC Privilege mode
show ip prefix-list summary [prefix-name]
Examples of the show ip prefix-list Commands
The following example shows the show ip prefix-list detail command.
Dell>show ip prefix detail
Prefix-list with the last deletion/insertion: filter_ospf
ip prefix-list filter_in:
count: 3, range entries: 3, sequences: 5 - 10
130
Access Control Lists (ACLs)