User guide

192 WatchGuard Firebox X Edge
SSL
See
Secure Sockets Layer .
stance
The policy of a firewall regarding the default handling of IP packets. Stance
dictates what the firewall will do with any given packet in the absence of
explicit instructions. The WatchGuard default stance is to discard all packets that
are not explicitly allowed, often stated as “That which is not explicitly allowed is
denied.”
star topology
A networking setup used with 10BASE-T cabling and a hub in which each node
on the network is connected to the hub like points of a star.
static NAT
Network address translation in which incoming packets destined for a public
address on an external network are remapped to an address behind the firewall.
stream cypher
A class of symmetric key encryption where transformation can be changed for
each symbol of plain text being encrypted; useful for equipment with little
memory to buffer data.
subnet
A network segment connected by hubs or repeaters. For example, one could take
a class C network with 256 available addresses and create two additional
netmasks under it that separate the first 128 and last 128 addresses into
separate identifiable networks. Subnetting enables a client with a single network
to create multiple networks; the advanced or multiple network configurations
can then be used when setting up the Firebox.
subnet mask
A 32-bit number used to identify which port of an IP address is masked.
substitution cypher
A method in which the characters of the plain text are substituted with other
characters to form the cipher text.
switch
A device that filters and forwards packets between LAN segments.
symmetric algorithm
Also called conventional, secret key, and single key algorithms; the encryption
and decryption key are either the same or can be calculated from one another.
SYN flood attack
A method of denying service to legitimate users by overloading a network with
illegitimate TCP connection attempts.