Configuring a Standard IP ACL Filter
If you are creating a standard ACL with only one or two filters, you can let the system assign a sequence
number based on the order in which the filters are configured. The software assigns filters in multiples of
five.
1. Configure a standard IP ACL and assign it a unique name.
CONFIGURATION mode
ip access-list standard access-list-name
2. Configure a drop or forward IP ACL filter.
CONFIG-STD-NACL mode
{deny | permit} {source [mask] | any | host ip-address} [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.
The following example shows a standard IP ACL in which the system assigns the sequence numbers. 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 IP ACCESS LIST
mode displays the two filters with the sequence numbers 5 and 10.
Examples of Viewing Filter Sequence Standard ACLs
The following example shows viewing a filter sequence for a specified standard ACL.
Dell(config-route-map)#ip access standard kigali
Dell(config-std-nacl)#permit 10.1.0.0/16
Dell(config-std-nacl)#show config
!
ip access-list standard kigali
seq 5 permit 10.1.0.0/16 seq 10 deny tcp any any eq 111
Dell(config-std-nacl)#
To view all configured IP ACLs, use the show ip accounting access-list command in EXEC
Privilege mode.
Dell#show ip accounting access example interface gig 4/12
Extended IP access list example
seq 10 deny tcp any any eq 111
seq 15 deny udp any any eq 111
seq 20 deny udp any any eq 2049
seq 25 deny udp any any eq 31337
seq 30 deny tcp any any range 12345 12346
seq 35 permit udp host 10.21.126.225 10.4.5.0 /28
seq 40 permit udp host 10.21.126.226 10.4.5.0 /28
seq 45 permit udp 10.8.0.0 /16 10.50.188.118 /31 range 1812 1813
seq 50 permit tcp 10.8.0.0 /16 10.50.188.118 /31 eq 49
seq 55 permit udp 10.15.1.0 /24 10.50.188.118 /31 range 1812 1813
To delete a filter, enter the show config command in IP ACCESS LIST mode and locate the sequence
number of the filter you want to delete. Then use the no seq sequence-number command in IP
ACCESS LIST mode.
Access Control Lists (ACLs) 99