port 25 is stealth, need it to be open. How?

[samueladams040]

I did a scan of my ports using Shields UP. It came back showing that port 25 is "stealth". Since I have been having some challenges from my exchange server, I wanted to know how can I make this port "open". This is needed for exchange to function properly.

thanks

 

[Salem]

What sort of network do you have - a lan with a firewall to the internet perhaps?

Or is it just a single machine with its own firewall connected directly to the internet.

You certainly don't want port 25 accessable from the internet. Otherwise you may become a source of spam as others exploit your machine to send their spam.

I would think you would want to arrange whatever firewall rules you have to allow local access to port 25, and be stealth from the internet.

 

[pansophic]

If port 25 is stealth from the internet, you cannot receive mail from internet hosts. You do want to configure your system such that it does not relay blindly, which as I recall is somewhat difficult with Exchange. I found a registry hack for limiting relaying, but can't recall where it is. I hope that Microsoft has learned from their mistake and made relaying rules a menu driven or INI file configuration in Exchange 5, but I wouldn't bet on it.

Another option, although a poor one in my opinion, that I have seen others use is to let your ISP be your internet mail server, and configure exchange to poll the mail on a routine basis. I believe that the minimum configurable value for Exchange was 15 minutes the last time that I checked. That is intolerably slow for people who are used to the instant gratification that is available by making your mailserver internet accessible. I've had to "fix" a couple of these setups.

Personally, I prefer sendmail and Postfix. It is simple to configure them to be internet safe (blocking blind relay).


pansophic

 

[ChrisAC]

It seems that you have a problem with your Exchange server configuration. If this is working correctly then you should have port TCP 25 available.

Chris.


**********************
Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
**********************

 

[pansophic]

Actually, I'd guess that either the ISP is blocking incoming port 25 (except for their SMTP servers) or you have a broadband router/firewall that does not have a port forwarding rule for 25.

Are you doing NAT at your location? Are you using a router or modem or firewall?


pansophic