Config Display Save Access Backup BlockADS Help

1. Open PORT

For example the user has selected protocol tcp, port 800 on external interface and port 80 for internal destination IP 172.25.1.10, the below commands will be executed by iBlocker:

iptables -t nat -A PREROUTING -p tcp -m tcp --dport 800 -j DNAT --to-destination 172.25.1.10:80

iptables -t nat -A POSTROUTING -d 172.25.1.10/32 -p tcp -m tcp --dport 80 -j SNAT --to-source 172.25.1.1

Display iptables: Chain PREROUTING (policy ACCEPT 0 packets, 0 bytes)

pktsbytestargetprotoptinoutsourcedestination
00DNATtcp--**0.0.0.0/00.0.0.0/0tcp dpt:800 to:172.25.1.10:80

Display iptables: Chain POSTROUTING (policy ACCEPT 0 packets, 0 bytes)

pktsbytestargetprotoptinoutsourcedestination
00SNATtcp--**0.0.0.0/0172.25.1.10tcp dpt:80 to:172.25.1.1

2. Close PORT

Closing port 800 protocol tcp for 172.25.1.10, below commands are executed by iBlocker:

iptables -t nat -D PREROUTING -p tcp -m tcp --dport 800 -j DNAT --to-destination 172.25.1.10:80

iptables -t nat -D POSTROUTING -d 172.25.1.10/32 -p tcp -m tcp --dport 80 -j SNAT --to-source 172.25.1.1