Basic doubts in NAT rule base.

[jagclinton]

Hi all,

I am new to checkpoint.
Please clarify my doubts in NAT.

When creating Automatic Dynamic NAT, 2 rules will be created.
I Rule: Network | Network | Any || = | = | =
II Rule: Network | Any | Any || Network(H) | Any | Any

Q). Why for I rule is created? If, any host in a network tries to contact with another host in the same network, the packet won't pass through the firewall.
Then why this rule is created automatically?

Am i wrong or else please explain me detail.

Regards,
Jagclinton.

[MarioL]

Well, that rule is pretty much useless yes, that's why I always do Hide NAT manually.

[melipla]

Originally Posted by jagclinton

Q). Why for I rule is created? If, any host in a network tries to contact with another host in the same network, the packet won't pass through the firewall.
Then why this rule is created automatically?

There are scenarios where you can route the traffic through the firewall even for the same network. Like the network broadcast address or policy based routing could be causes.