WatchGuard Technologies WatchGuard Firebox SOHO 6 - Manual (Page 23)

User Guide 5
How Does the SOHO 6 Process Information?
Port numbers
The port numbers are used by computers at both the sending and
receiving end to determine the particular program or application
for each connection.
How Does the SOHO 6 Process Information?
Services
A service is the combination of protocol(s) and port numbers
associated with a specific program or application type. To simplify
configuration of your SOHO 6, WatchGuard configured versions
of several common services are available for your use.
Network Address Translation
All outgoing connections through a SOHO 6 automatically use a
feature called dynamic NAT (Network Address Translation).
Without dynamic NAT, your trusted, private addresses are passed
along the Internet to their destination.
In addition, the SOHO 6 protects your trusted network by
disguising private IP addresses. During an Internet connection, all
traffic passed between computers includes IP address information.
However, because of the dynamic NAT feature, applications and
servers on the Internet only see the public, external IP address of
the SOHO 6 itself and are never aware of the addresses in your
trusted, network address range.
Imagine that you install a computer behind the SOHO 6 with the
IP address 206.253.208.100. If this address were broadcast to the
Internet, hackers could easily direct an attack on the computer
itself. Instead, the SOHO 6 converts the address automatically to