User guide

User Guide 181
MD5 (Message Digest 5)
An improved, more complex version of MD4, but still a 128-bit, one-way hash
function.
message digest
A number that is derived from a message. A change to a single character in the
message will cause it to have a different message digest.
MIME (Multipurpose Internet Mail Extensions)
Extensions to the SMTP format that allow binary data, such as that found in
graphic files or documents, to be published and read on the Internet.
modem
A communications device that sends computer transmissions over a standard
telephone line.
motherboard
The main printed circuit board in a computer, which contains sockets that
accept additional boards (daughterboards).
MSDUN
Microsoft Dial-Up Networking is an executable program required for remote user
VPN.
multiple network configuration
A configuration used in situations in which a Firebox is placed with separate
logical networks on its interface.
National Institute for Standards and Technology
A division of the U.S. Department of Commerce that publishes open
interoperability standards called Federal Information Processing Standards
(FIPSs).
network address
The network portion of an IP address. For a class A network, the network
address is the first byte of the IP address. For a class B network, the network
address is the first two bytes of the IP address. For a class C network, the
network address is the first three bytes of the IP address. In each case, the
remainder is the host address. In the Internet, assigned network addresses are
globally unique.
network address translation (NAT)
A method of hiding or masquerading network addresses from hosts on another
network, protecting the confidentiality and architecture of the network.
netmask
An inverse mask of the significant bits of a network address. On a local net, the
range of addresses one can expect to be found directly connected to the
network. Because netmasks generally occur with a Class C license address space
of 8 bits, the netmask is 255.255.255.0. It can be a smaller number of bits if