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intra-area routing
Routing that occurs within a logical area. Contrast
with: inter-area routing.
intruder detection
Intruder detection systems operate by monitoring the
data flow for characteristics consistent with security threats. In this manner,
an intruder can be monitored or blocked from access. One trigger for an
intruder detection system is multiple ping packets from a single resource in
a brief period of time.
Inverse ARP
Inverse Address Resolution Protocol: A technique by which
dynamic mappings are constructed in a network, allowing a device such as
a router to locate the logical network address and associate it with a perma-
nent virtual circuit (PVC). Commonly used in Frame Relay to determine the
far-end node's TCP/IP address by sending the Inverse ARP request to the
local DLCI.
Internet Protocol: Defined in RFC 791, it is a Network layer protocol
that is part of the TCP/IP stack and allows connectionless service. IP fur-
nishes an array of features for addressing, type-of-service specification, frag-
mentation and reassembly, and security.
IP address
Often called an Internet address, this is an address uniquely
identifying any device (host) on the Internet (or any TCP/IP network). Each
address consists of four octets (32 bits), represented as decimal numbers sep-
arated by periods (a format known as "dotted-decimal"). Every address is
made up of a network number, an optional subnetwork number, and a host
number. The network and subnetwork numbers together are used for
routing, while the host number addresses an individual host within the net-
work or subnetwork. The network and subnetwork information is extracted
from the IP address using the subnet mask. There are five classes of IP
addresses (A­E), which allocate different numbers of bits to the network,
subnetwork, and host portions of the address. See also: CIDR, IP, and
subnet mask.
IP Control Program: The protocol used to establish and configure IP
over PPP. See also: IP and PPP.
IP multicast
A technique for routing that enables IP traffic to be repro-
duced from one source to several endpoints or from multiple sources to
many destinations. Instead of transmitting only one packet to each indi-
vidual point of destination, one packet is sent to a multicast group specified
by only one IP endpoint address for the group.
Copyright ©2001 SYBEX , Inc., Alameda, CA