Chek if it's installed:

lslpp -l | grep ipsec

Start:

smit ipsec4
Start/Stop IP Security
Start IP Security
Start IP Security                                  [Now and After Reboot]

Specific network interface:

genfilt -v4 -a D -s 10.149.128.122 -m 255.255.255.0 -d 10.149.128.123 -M 255.255.255.0 -g N -c tcp -o eq -p 80 -r L -w I -l N -f Y -i en0

All interfaces:

genfilt -v4 -a D -s 10.149.128.122 -m 255.255.255.0 -d 10.149.128.123 -M 255.255.255.0 -g N -c tcp -o eq -p 80 -r L -w I -l N -f Y -i all

The same but locally:

genfilt -v4 -a D -s 10.149.128.122 -m 255.255.255.0 -d 10.149.128.123 -M 255.255.255.0 -g N -c tcp -O eq -P 80 -r L -w O -l N -f Y -i en0

The same but locally with all interfaces:

genfilt -v4 -a D -s 10.149.128.122 -m 255.255.255.0 -d 10.149.128.123 -M 255.255.255.0 -g N -c tcp -O eq -P 80 -r L -w O -l N -f Y -i all

¿What meaning the above?

• -v4: use IPv4 rles
• -a D: action Deny
• -s 10.149.128.122: source address
• -m 255.255.255.0: source subnet mask
• -d 10.149.128.123: destination address
• -M 255.255.255.0: destination subnet mask
• -g N: use source routing No
• -c tcp: apply to tcp protocol
• -O eq: destination port condition (lt, le, gt, ge, eq, neq, and any)
• -P: destination port
• -r L: apply the rule for destined and local packets
• -w O: apply the rule for outbound packets
• -l N: no log
• -f Y: Control all packets fragmented or no
• -i all: all interfaces

Apply changes:

mkfilt -g start
mkfilt -u

List rules:

lsfilt -a -v4

Restart IPSec:

smit ipsec4

Remove all rules:

rmfilt -v4 -n all
mkfilt -g start
mkfilt -u

• https://www.ibm.com/support/knowledgecenter/en/ssw_aix_71/com.ibm.aix.cmds2/genfilt.htm