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Firewall-1: Can Internal Hosts Share One Public IP With Static and Hidden NAT?

We have two mail servers: one for incoming mail and one for outgoing, and both are behind Firewall-1. I want them to be seen on the Internet as a single IP address. Can I have a single common public address that exists both in a static and hidden translation rule at the same time?

I would configure the incoming mail server with a static rule, so that incoming packets to that public IP get directed by the firewall to the incoming mail server. I would configure the outgoing mail server with a hidden automatic NAT rule that points to the same public IP, so that outgoing packets from that mail server get NAT'd to the common public IP.

I know this works for more than one host to share one public IP using hidden translation, but I don't know yet if it would work with a single public IP using both a static and hidden rule. Any advice on this is appreciated.

Reply to
Will
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Will wrote: : We have two mail servers: one for incoming mail and one for outgoing, and : both are behind Firewall-1. I want them to be seen on the Internet as a : single IP address. Can I have a single common public address that exists : both in a static and hidden translation rule at the same time?

Try using a normal automatic static setup for the inbound connection and setup a manual rule with a hide rule for the outbound connection.

Lars

Reply to
larstr

Lookup "smtp security server" in the help files, you'll need that to get the incoming mail traffic working. If you're not sure, check CD2 and the \\Docs directory.

Wayne McGlinn Brisbane, Oz

Reply to
Wayne

Wayne wrote: : Lookup "smtp security server" in the help files, you'll need that to get the : incoming mail traffic working. If you're not sure, check CD2 and the \\Docs : directory.

I guess the reasons he wants to do this is because he wants to put an extra email filtering box in the mail flow? He didn't specify, but it's a very common thing to do now. The SMTP Security Server used to be very widely used a few years ago. As the years passed, the spam problem increased while the SMTP Securiy Server remained unchanged.

You can still use the SMTP Sercuriy server in front of your spam filtering server but you'll loose potential functionality such as delaying (also known as greylisting), DNSBL, HELO blacklisting and you won't be able to block emails at the SMTP level that will avoid your systems from sending faulty NDRs.

Lars

Reply to
larstr

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