Users Guide

Conguring Filters with a Sequence Number
To congure lters with a sequence number, use the following commands.
1. Enter IP ACCESS LIST mode by creating an extended IP ACL.
CONFIGURATION mode
ip access-list extended access-list-name
2. Congure a drop or forward lter.
CONFIG-EXT-NACL mode
seq sequence-number {deny | permit} {ip-protocol-number | icmp | ip | tcp | udp} {source
mask | any | host ip-address} {destination mask | any | host ip-address} [operator port
[port]] [count [byte]] [order] [fragments]
When you use the log keyword, the CP logs details about the packets that match. Depending on how many packets match the log
entry and at what rate, the CP may become busy as it has to log these packets’ details.
Congure Filters, TCP Packets
To create a lter for TCP packets with a specied sequence number, use the following commands.
1. Create an extended IP ACL and assign it a unique name.
CONFIGURATION mode
ip access-list extended access-list-name
2. Congure an extended IP ACL lter for TCP packets.
CONFIG-EXT-NACL mode
seq sequence-number {deny | permit} tcp {source mask | any | host ip-address} [count
[byte]] [order] [fragments]
Congure Filters, UDP Packets
To create a lter for UDP packets with a specied sequence number, use the following commands.
1. Create an extended IP ACL and assign it a unique name.
CONFIGURATION mode
ip access-list extended access-list-name
2. Congure an extended IP ACL lter for UDP packets.
CONFIG-EXT-NACL mode
seq sequence-number {deny | permit} tcp {source mask | any | host ip-address} [count
[byte]] [order] [fragments]
Example of the seq Command
When you create the lters with a specic sequence number, you can create the lters in any order and the lters are placed in the
correct order.
NOTE: When assigning sequence numbers to lters, you may have to insert a new lter. To prevent reconguring multiple
lters, assign sequence numbers in multiples of ve or another number.
The example below shows how the seq command orders the lters according to the sequence number assigned. In the example,
lter 15 was congured before lter 5, but the show config command displays the lters in the correct order.
Dell(config-ext-nacl)#seq 15 deny ip host 112.45.0.0 any log
Dell(config-ext-nacl)#seq 5 permit tcp 12.1.3.45 0.0.255.255 any
116
Access Control Lists (ACLs)