topic Hi Jose, in Network Security

Multiple Nat/Pat scenario

rodexitsupport123 — Tue, 12 Mar 2019 07:15:09 GMT

Hi there,

I am PATing a public IP, lets say 1.1.1.1 port 80 to port 4000 on server1

then I am PATing 1.1.1.1 port 25 to 25 on server 2.

The emails for some reason are not going out on server 2 using that port, even though it is configured for port 25 outbound.

When I take both PATs away and simply NAT 1.1.1.1 to server 2, everything works fine.

This is telling me that the outgoing mail is using another port and I cant figure out which one (even the developer of the application says it just uses port 25).

Is there any way I can have NAT 1.1.1.1 to server 2 and PAT 1.1.1.1 port 80 to server 1 port 4000.

If I try the above then i get an error saying it is overlapping the NAT.

Or is there any way of saying that 1.1.1.1 port 80 must be Natted to Server1 port 4000, but any other incoming ports must go to server 2.

thanks

Hello rodexitsupport123,

joseoroz — Tue, 09 Feb 2016 01:09:12 GMT

Hello rodexitsupport123,

Can you post the configuration also what code is your device running?

When you are talking about PAT I assume that you are doing a port forwarding? If that is the case the static NAT is going to be for the destination when you send the traffic from a remote client the destination will be the port 25. Then the source port of the reply will be 25 and the destination the random port of the initial request.

Please provide that information so we can have a better idea of your setup.

Regards,

Jose Orozco.

Hi Jose,

rodexitsupport123 — Tue, 09 Feb 2016 09:59:33 GMT

Hi Jose,

I have figured out the solution.

What I needed was a global PAT for the 1.1.1.1 IP. so that it can access the internet through all ports.

so:

nat (inside) 2 server2 255.255.255.255
global (outside) 2 1.1.1.1

thanks