Successful AS2 communications require a balancing act between two conflicting demands: your infrastructure has to be open enough to talk with your trading partners, but secure enough to keep out intruders and repel attacks. The familiar firewall is the tool of choice to resolve this, but it still requires that you tell your trading partner which ports are open. This could expose your network to security lapses on their end. Fortunately, there are several options available to minimize or eliminate this risk.
An obvious solution is to restrict incoming traffic only to the known IP addresses of your trading partners. While this is a good start, some other problems present themselves. Continue reading