AIX must be configured with a default gateway for IPv4 if the system uses IPv4, unless the system is a router.

If a system has no default gateway defined, the system is at increased risk of man-in-the-middle, monitoring, and Denial of Service attacks.

Check the system for an IPv4 default route using command:

# netstat -r |grep default default 10.11.20.1 UG 1 1811 en0 - -

If a default route is not defined, this is a finding.

Set a default gateway for IPv4 using: # route add 0 <ip address of gateway>