SSH_P=4224

KN_SSH_P1=53486
KN_SSH_P2=23597
KN_SSH_P3=47354

ipt -A in_inetbr -p tcp --dport ${KN_SSH_P1} -j knock_ssh_g1
ipt -A in_inetbr -p tcp --dport ${KN_SSH_P2} -m recent --rcheck --seconds 30 --name knock_ssh_a1 -j knock_ssh_g2
ipt -A in_inetbr -p tcp --dport ${KN_SSH_P3} -m recent --rcheck --seconds 30 --name knock_ssh_a2 -j knock_ssh_g3
ipt -A in_inetbr -p tcp --dport ${SSH_P} -m recent --rcheck --seconds 30 --name knock_ssh_a3 -j knock_ssh_pass