Reference Guide

Access Control Lists (ACLs) | 73
UDP packets: To create a filter for UDP packets with a specified sequence number, use these commands
in the following sequence, starting in the CONFIGURATION mode:
When you create the filters with a specific sequence number, you can create the filters in any order and the
filters are placed in the correct order.
Figure 6-6 illustrates how the
seq command orders the filters according to the sequence number assigned.
In the example, filter 15 was configured before filter 5, but the
show config command displays the filters in
the correct order.
Figure 6-6. Command Example: seq
Configure filters without sequence number
If you are creating an extended ACL with only one or two filters, you can let FTOS assign a sequence
number based on the order in which the filters are configured. FTOS assigns filters in multiples of 5.
Step Command Syntax Command Mode Purpose
1
ip access-list extended
access-list-name
CONFIGURATION Create a extended IP ACL and assign it a unique
name.
2 seq sequence-number
{
deny | permit}
{ip-protocol-number
udp} {source mask |
any | host ip-address}
{
destination mask |
any | host ip-address}
[
operator port [port]]
[
count [byte] [dscp]
[
order] [fragments]
CONFIG-EXT-NACL Configure an extended IP ACL filter for UDP
packets.
Note: When assigning sequence numbers to filters, keep in mind that you might need to insert a
new filter. To prevent reconfiguring multiple filters, assign sequence numbers in multiples of five or
another number.
FTOS(config-ext-nacl)#seq 15 deny ip host 112.45.0.0 any log
FTOS(config-ext-nacl)#seq 5 permit tcp 12.1.3.45 0.0.255.255 any
FTOS(config-ext-nacl)#show confi
!
ip access-list extended dilling
seq 5 permit tcp 12.1.0.0 0.0.255.255 any
seq 15 deny ip host 112.45.0.0 any log
FTOS(config-ext-nacl)#