MD5.SYS

Used by the Firewall built into TCP/IP 4.1 and above. This driver adds MD5 encryption to the Firewall. Device driver used by the IBM TCP/IP Firewall to implement MD5 encryption. This is RSA's message digest algorithm used to provide authentication and integrity verification. DEVICE=\MPTN\PROTOCOL\MD5.SYS

There are several tools to configure the firewall:
 * Zampa:
 * ServerConfig: http://www.michelinakis.gr/Dimitris/sc/index.html