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The following example shows how the seq command orders the filters according to the sequence number assigned. In the
example, filter 20 was configured before filter 15 and 12, but the show config command displays the filters in the correct
order.
DellEMC(conf-nprefixl)#seq 20 permit 0.0.0.0/0 le 32
DellEMC(conf-nprefixl)#seq 12 deny 134.23.0.0 /16
DellEMC(conf-nprefixl)#seq 15 deny 120.23.14.0 /8 le 16
DellEMC(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
DellEMC(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 no seq sequence-number command in PREFIX LIST mode.If you are creating a standard prefix
list with only one or two filters, you can let Dell EMC Networking OS assign a sequence number based on the order in which the
filters are configured. The Dell EMC Networking OS 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).
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 two filters with the sequence numbers 5 and
10.
DellEMC(conf-nprefixl)#permit 123.23.0.0 /16
DellEMC(conf-nprefixl)#deny 133.24.56.0 /8
DellEMC(conf-nprefixl)#show conf
!
ip prefix-list awe
seq 5 permit 123.23.0.0/16
seq 10 deny 133.0.0.0/8
DellEMC(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
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Access Control Lists (ACLs)