Watchguard Firebox X1000 Reference Manual page 143

Reference Guide
NetBEUI is not routable, network transmissions sent via NetBEUI
cannot be transmitted over the Internet.
network address translation (NAT)
A method of hiding internal network addresses from hosts on an
external network.
MAC (Machine Authentication Code)
A key-dependent, one-way hash function, requiring the use of the
identical key to verify the hash.
MAC address
Media Access Control address that is unique to a computer, and is
used to identify its hardware.
masquerading
A method of setting up addressing so that a firewall presents its
IP address to the outside world in lieu of the IP addresses of the
hosts protected by the firewall.
Mazameter
See Bandwidth Meter.
MD2 (Message Digest 2)
A 128-bit, one-way hash function that is dependent on a random
permutation of bytes.
MD4 (Message Digest 4)
A 128-bit, one-way hash function that uses a simple set of bit
manipulations on 32-bit operands.
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.
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