Dell C9000 Series Networking Configuration Manual page 139

ip access-list extended access-list-name
2 Configure a drop or forward filter.
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.
Configure Filters, TCP Packets
To create a filter for TCP packets with a specified 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 Configure an extended IP ACL filter for TCP packets.
CONFIG-EXT-NACL mode
seq sequence-number {deny | permit} tcp {source mask | any | host ip-address}}
[count [byte]] [order] [fragments]
Configure Filters, UDP Packets
To create a filter for UDP packets with a specified 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 Configure an extended IP ACL filter 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 filters with a specific sequence number, you can create the filters in any order and the
filters are placed in the correct order.
NOTE: When assigning sequence numbers to filters, you may have to insert a new filter. To prevent
reconfiguring multiple filters, assign sequence numbers in multiples of five or another number.
The example below shows 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.
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
Access Control Lists (ACLs) 139