Cisco Catalyst 2960-XR Security Configuration Manual page 168

IPv4 ACL Configuration Examples
In this example, standard named access list stan1 denies traffic from 10.1.1.0 0.0.0.255, allows traffic from
all other sources, and includes the log keyword.
Switch(config)# ip access-list standard stan1
Switch(config-std-nacl)# deny 10.1.1.0 0.0.0.255 log
Switch(config-std-nacl)# permit any log
Switch(config-std-nacl)# exit
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# ip access-group stan1 in
Switch(config-if)# end
Switch# show logging
Syslog logging: enabled (0 messages dropped, 0 flushes, 0 overruns)
Console logging: level debugging, 37 messages logged
Monitor logging: level debugging, 0 messages logged
Buffer logging: level debugging, 37 messages logged
File logging: disabled
Trap logging: level debugging, 39 message lines logged
Log Buffer (4096 bytes):
00:00:48: NTP: authentication delay calculation problems
<output truncated>
00:09:34:%SEC-6-IPACCESSLOGS:list stan1 permitted 0.0.0.0 1 packet
00:09:59:%SEC-6-IPACCESSLOGS:list stan1 denied 10.1.1.15 1 packet
00:10:11:%SEC-6-IPACCESSLOGS:list stan1 permitted 0.0.0.0 1 packet
This example is a named extended access list ext1 that permits ICMP packets from any source to 10.1.1.0
0.0.0.255 and denies all UDP packets.
Switch(config)# ip access-list extended ext1
Switch(config-ext-nacl)# permit icmp any 10.1.1.0 0.0.0.255 log
Switch(config-ext-nacl)# deny udp any any log
Switch(config-std-nacl)# exit
Switch(config)# interface gigabitethernet1/0/2
Switch(config-if)# ip access-group ext1 in
This is a an example of a log for an extended ACL:
01:24:23:%SEC-6-IPACCESSLOGDP:list ext1 permitted icmp 10.1.1.15 -> 10.1.1.61 (0/0), 1
packet
01:25:14:%SEC-6-IPACCESSLOGDP:list ext1 permitted icmp 10.1.1.15 -> 10.1.1.61 (0/0), 7
packets
01:26:12:%SEC-6-IPACCESSLOGP:list ext1 denied udp 0.0.0.0(0) -> 255.255.255.255(0), 1 packet
01:31:33:%SEC-6-IPACCESSLOGP:list ext1 denied udp 0.0.0.0(0) -> 255.255.255.255(0), 8 packets
Note that all logging entries for IP ACLs start with %SEC-6-IPACCESSLOG with minor variations in format
depending on the kind of ACL and the access entry that has been matched.
This is an example of an output message when the log-input keyword is entered:
00:04:21:%SEC-6-IPACCESSLOGDP:list inputlog permitted icmp 10.1.1.10 (Vlan1 0001.42ef.a400)
->
10.1.1.61 (0/0), 1 packet
A log message for the same sort of packet using the log keyword does not include the input interface
information:
00:05:47:%SEC-6-IPACCESSLOGDP:list inputlog permitted icmp 10.1.1.10 -> 10.1.1.61 (0/0), 1
packet
Catalyst 2960-XR Switch Security Configuration Guide, Cisco IOS Release 15.0(2)EX1
146
Configuring IPv4 ACLs
OL-29434-01