Configure A Prefix List - Dell Force10 C150 Configuration Manual

The following list includes the configuration tasks for prefix lists:
• Configure a prefix list on page 154
• Use a prefix list for route redistribution on page 156
For a complete listing of all commands related to prefix lists, refer to the
Reference

Configure a prefix list

To configure a prefix list, use these commands in the following sequence, starting in the
CONFIGURATION mode:
Step Command Syntax
ip prefix-list
1
seq
2
sequence-number
permit }
min-prefix-length
max-prefix-length
If you want to forward all routes that do not match the prefix list criteria, you must configure a prefix list
filter to permit all routes (
prefix list. To permit the default route only, enter
Figure 8-13
In the example, filter 20 was configured before filter 15 and 12, but the
the filters in the correct order.
Figure 8-13. Command Example: seq
FTOS(conf-nprefixl)#seq 20 permit 0.0.0.0/0 le 32
FTOS(conf-nprefixl)#seq 12 deny 134.23.0.0 /16
FTOS(conf-nprefixl)#seq 15 deny 120.23.14.0 /8 le 16
FTOS(conf-nprefixl)#show config
!
ip prefix-list juba
seq 12 deny 134.23.0.0/16
seq 15 deny 120.0.0.0/8 le 16
seq 20 permit 0.0.0.0/0 le 32
FTOS(conf-nprefixl)#
Note the last line in the prefix list Juba contains a "permit all" statement. By including this line in a prefix
list, you specify that all routes not matching any criteria in the prefix list are forwarded.
To delete a filter, use the
154 | IP Access Control Lists (ACL), Prefix Lists, and Route-maps
document.
prefix-name
{ deny |
[ ge
ip-prefix
] [ le
]
permit 0.0.0.0/0 le 32
seq
illustrates how the
no seq
sequence-number
Command Mode
CONFIGURATION
CONFIG-NPREFIXL
). The "permit all" filter should be the last filter in your
permit 0.0.0.0/0
command orders the filters according to the sequence number assigned.
command in the PREFIX LIST mode.
FTOS Command Line Interface
Purpose
Create a prefix list and assign it a unique
name.
You are in the PREFIX LIST mode.
Create a prefix list with a sequence number
and a deny or permit action. The optional
parameters are:
ge
• is the minimum
min-prefix-length:
prefix length to be matched (0 to 32).
le
• is the maximum
max-prefix-length:
prefix length to be matched (0 to 32).
.
show config
command displays