The Eagle provides security by completely isolating all external networks from your internal network. Except for e-mail via the Simple Mail Transport Protocol (SMTP), no IP data from an outside host can directly reach a host on the inside unless you permit it. The Eagle lets you specify, for each machine on your network, exactly what kind of communication will be allowed and when. For example, you can authorize physically remote users to upload data to your system during working hours and yet allow no access of any kind during off-hours. Similarly, you can restrict your users' access to outside hosts.
The Eagle repackages all IP packets it passes, rewriting packet headers to hide information about your internal network. This decreases your vulnerability, as potential attackers are given no information to substantiate or expand on what they may have gleaned from other sources.