Internet Control Message Protocol is the part of the TCP/IP protocol that allows generation of error
messages, test packets, and operating messages. For example, the ping command allows you to send
ICMP echo messages to a remote IP device to test for connectivity. ICMP also supports traceroute,
which identifies intermediate hops between a given source and destination.
IGMP
Hosts use Internet Group Management Protocol to inform local routers of their membership in multicast
groups. Multicasting allows one computer on the Internet to send content to multiple other computers
that have identified themselves as interested in receiving the originating computer's content. When all
hosts leave a group, the router no longer forwards packets that arrive for the multicast group.
LLDP
Link Layer Discovery Protocol conforms to IEEE 802.1ab and is a neighbor discovery protocol. Each
LLDP-enabled device transmits information to its neighbors, including chassis and port identification,
system name and description, VLAN names, and other selected networking information. The protocol
also specifies timing intervals in order to ensure current information is being transmitted and received.
MD5
Message-Digest algorithm is a hash function that is commonly used to generate a 128-bit hash value. It
was designed by Ron Rivest in 1991. MD5 is officially defined in RFC 1321 - The MD5 Message-Digest
Algorithm.
MIC
Message Integrity Check (or Code), also called ‘Michael’, is part of WPA and TKIP. The MIC is an
additional 8-byte code inserted before the standard 4-byte ICV appended in by standard WEP to the
802.11 message. This greatly increases the difficulty in carrying out forgery attacks.
Both integrity check mechanisms are calculated by the receiver and compared against the values sent
by the sender in the frame. If the values match, there is assurance that the message has not been
tampered with.
netmask
A netmask is a string of 0s and 1s that mask, or screen out, the network part of an IP address, so that
only the host computer part of the address remains. A frequently-used netmask is 255.255.255.0, used
for a Class C subnet (one with up to 255 host computers). The ".0" in the netmask allows the specific
host computer address to be visible.
PEAP
Protected Extensible Authentication Protocol is an IETF draft standard to authenticate wireless LAN
clients without requiring them to have certificates. In PEAP authentication, first the user authenticates
the authentication server, then the authentication server authenticates the user. If the first phase is
successful, the user is then authenticated over the SSL tunnel created in phase one using EAP-Generic
Token Card (EAP-GTC) or Microsoft Challenged Handshake Protocol Version 2 (MSCHAP V2). (See also
QoS
Quality of Service is a technique that is used to manage network resources and guarantee a bandwidth
relationship between individual applications or protocols. A communications network transports a
multitude of applications and data, including high-quality video and delay-sensitive data such as real-
Glossary
