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New Member

Port redirection issue

Is it possible to redirect smtp traffic from 2 external addresses to 1 internal address?

I need to do this and get static overlap errors.

Setup is (real address not shown) is inside mail server

there is no nat for this device so it goes out on the outside as

nat (inside) 0

static (inside, outside) netmask

I have 2 addresses on the outside that I would like to redirect to the internal address.

The commands that I would use are

static (inside,outside) tcp 195.106.x.x smtp 25 smtp netmask

static (inside,outside) tcp 193.132.x.x smtp 25 smtp netmask

Is it possible to do this?

Can 2 oustide addresses be mapped to one inside address?

New Member

Re: Port redirection issue

I think you have to modify the static and the internal server ports used for smtp.

for example

static (inside,outside) tcp 195.106.x.x smtp 1601netmask

static (inside,outside) tcp 193.132.x.x smtp 1602 netmask

If you have the abiity to change your mail server to listen for SMTP on diffenrent ports ( I picked 1601 and 1602 for no apparent reason ) then you should nt get overlaps.

New Member

Re: Port redirection issue


Tried that.

I still get the "error static overlaps" message when I enter the first static command.

I tried specifying a different ip address e.g. and it accepted the first line. When I tried adding the second static line it said "static error".

Does it not allow you to have 2 redirects to the same address?

New Member

Re: Port redirection issue

I thought it would - I know that the intention of the command is opposite from what you are trying. - to allow you to use one outside IP for multiple inside services...

An example of my config shows that it would work if you used two differnet services on the outside ports as well - but that would detfeat the purpose of what you are trying to do.

Sorry I couldn't be more help.

New Member

Re: Port redirection issue

Try again - but clear xlate first - I just tried it on a test box and it works.

static (DMZ,outside) tcp smtp 1601 netmask

static (DMZ,outside) tcp smtp 1602 netmask

If not upgrade to 6.3.1

Good Luck

New Member

Re: Port redirection issue

Already on 6.3.1

The problem I get is that the internal host already has a static mapping to an external address.

If I add the port redirection command I get an "ERROR: static overlaps" message.

Re: Port redirection issue


Is it possible to do this? Sorry, but it is not possible.

It is only possible is you define different services (so not smtp twice).

Kind Regards,



Re: Port redirection issue

Hi Adrian -

I don't know if you have read or seen this document, might be of help to you :

Hope this helps --