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Cisco Router and Security Device Manager Version 2.2 User’s Guide
OL-4015-08
Glossary
MD5 Message Digest 5. A one-way hashing function that produces a 1 28-bit hash.
Both MD5 and Secure Hashing Algorithm (SHA) are variations on MD4 and are
designed to strengthen the security of the MD4 hashing algor ithm. Cisco uses
hashes for authentication within the IPSec framework. MD5 verifies the
integrity and authenticates the origin of a communication.
message digest A string of bits that represents a larger data block. This string defines a data
block, based on the processing of its precise content through a 128-bit hash
function. Message digests are used in the generation of digital signatures. See
hash.
MD5 Message Digest 5. A one-way hashing algorithm that produces a 128-bit hash.
Both MD5 and Secure Hash Algorithm (SHA) are variations on MD4 and are
designed to strengthen the security of the MD4 hashing algor ithm. Cisco uses
hashes for authentication within the IPSec framework. Also used for message
authentication in SNMP v.2. MD5 verifies the integrity of the communication,
authenticates the origin, and checks for timeliness.
mGRE multipoint GRE.
MTU maximum transmission unit. The maximum packet size, in bytes that an
interface can transmit or receive.
N
NAC Network Admission Control. A method of controlling access to a network in
order to prevent the introduction of computer viruses. Using a variety of
protocols and software products, NAC assesses the condition of hosts when they
attempt to log onto the network, and handles the request based on the host’s
condition, called its posture. Infected hosts can be placed in quarantine; hosts
without up-to-date virus protection software can be directed to obtain updates,
and uninfected hosts with up-to-date virus protection can be allowed onto the
network. See also ACL, posture, and EAPoUDP.