The network device must log all access control lists (ACL) deny statements.
Auditing and logging are key components of any security architecture. It is essential for security personnel to know what is being done, attempted to be done, and by whom in order to compile an accurate risk assessment. Auditing the actions on network devices provides a means to recreate an attack, or identify a configuration mistake on the device.
Configure interface ACLs to log all deny statements.
Review the network device interface ACLs to verify all deny statements are logged. Cisco IOS example: interface FastEthernet 0/0 description external interface peering with ISP or non-DoD network ip address 126.96.36.199 255.255.255.252 ip access-group 100 in … access-list 100 deny icmp any any fragments log access-list 100 deny ip 169.254.0.0 0.0.255.255 any log access-list 100 deny ip 10.0.0.0 0.255.255.255 any log access-list 100 deny ip 172.16.0.0 0.15.255.255 any log access-list 100 deny ip 192.168.0.0 0.0.255.255 any log access-list 100 permit icmp any host 188.8.131.52 echo-reply access-list 100 permit icmp any host 184.108.40.206 echo-reply access-list 100 deny icmp any any log access-list 100 deny ip any any log
Information Assurance Officer
ECAT-1, ECAT-2, ECSC-1