ipfw and mail

[James Housley]

On Jun 25, 2004, at 2:00 PM, Gustavo A. Baratto wrote:

> Hello guys,
>
> some of our users' ISPs don't allow them to use port 25, so they 
> cannot use out mail server.
>
> I want to open a new port (2525) and forward all packets from 2525 to 
> 25 so, they can use mail.
>
> I tried this in IPFW:
> 0100 119649 44772439 allow tcp from any to me dst-port 25 keep-state
> 0200      0        0 divert 25 ip from any to me dst-port 2525 
> keep-state
> 0300 103075 35531648 allow ip from me to any keep-state
> 0400     60     4530 deny log ip from any to any
>
>
> If I telnet directly to port 25, I can get the prompt, but if I telnet 
> to port 2525, I get a connection refused.
>
> What should I do in ipfw to forward port 2525 to port 25 tranparently?
>

I have done that with natd and ipfw.  I think you want a forward rule 
instead of divert

Jim
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