User's Manual Part 2

Server
304 Check Point Safe@Office User Guide
S
Server
A server is a program (or host)
that awaits and requests from
client programs across the
network. For example, a Web
server is the computer program,
running on a specific host, that
serves requested HTML pages or
files. Your browser is the client
program, in this case.
Stateful Inspection
Stateful Inspection was invented
by Check Point to provide the
highest level of security by
examining every layer within a
packet, unlike other systems of
inspection. Stateful Inspection
extracts information required for
security decisions from all
application layers and retains
this information in dynamic state
tables for evaluating subsequent
connection attempts. In other
words, it learns!
Subnet Mask
A 32-bit identifier indicating
how the network is split into
subnets. The subnet mask
indicates which part of the IP
address is the host ID and which
indicates the subnet.
T
TCP
TCP (Transmission Control
Protocol) is a set of rules
(protocol) used along with the
Internet Protocol (IP) to send
data in the form of message units
between computers over the
Internet. While IP takes care of
handling the actual delivery of
the data, TCP takes care of
keeping track of the individual
units of data (called packets) that
a message is divided into for
efficient routing through the
Internet.
For example, when an HTML
file is sent to you from a Web
server, the Transmission Control
Protocol (TCP) program layer in
that server divides the file into
one or more packets, numbers
the packets, and then forwards
them individually to the IP
program layer. Although each
packet has the same destination
IP address, it may get routed
differently through the network.
At the other end (the client
program in your computer), TCP
reassembles the individual
packets and waits until they have
arrived to forward them to you
as a single file.