Acl Logging - Cisco Catalyst 3550 series Software Configuration Manual

Chapter 28 Configuring Network Security with ACLs
In this example of a named ACL, the Jones subnet is not allowed access:
Switch(config)# ip access-list standard prevention
Switch(config-std-nacl)# remark Do not allow Jones subnet through
Switch(config-std-nacl)# deny 171.69.0.0 0.0.255.255
In this example of a named ACL, the Jones subnet is not allowed to use outbound Telnet:
Switch(config)# ip access-list extended telnetting
Switch(config-ext-nacl)# remark Do not allow Jones subnet to telnet out
Switch(config-ext-nacl)# deny tcp 171.69.0.0 0.0.255.255 any eq telnet

ACL Logging

Logging is not supported on port ACLs.
Note
Two variations of logging are supported on router ACLs. The log keyword sends an informational
logging message to the console about the packet that matches the entry; the log-input keyword includes
the input interface in the log entry.
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 gigabitethernet0/1
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)
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
00:15:33:%SEC-6-IPACCESSLOGS:list stan1 denied 10.1.1.15 2009 packets
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 gigabitethernet0/3
Switch(config-if)# ip access-group ext1 in
78-11194-09
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
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring IP ACLs
28-25