Technical data

address resolution
The process of relating an IP address to a hardware address, when both refer to
the same device, for example, conversion of an IP address into the corresponding
Ethernet, Token Ring, or FDDI hardware address. This may require broadcasting
on a local network. See also Address Resolution Protocol.
Address Resolution Protocol (ARP)
The TCP/IP protocol that dynamically binds an IP address to a hardware address
such as an Ethernet or FDDI address; limited to physical network systems that
support broadcast packets that can be heard by all hosts on a single, physical
network. See also proxy ARP.
addressing
The function that ensures that network systems are correctly identified a
talltimes.
addressing authority
The authority, such as the American National Standards Institute (ANSI),
responsible for assigning Network Interface layer addresses within an addressing
domain.
addressing domain
A level in a hierarchy of Network Interface layer addresses.
adjacency
A single connection to an adjacent node; collection of state information representing
a node in the local node’s routing databases.
A relationship formed between selected neighboring routers for the purpose of
exchanging routing information. Not every pair of neighboring routers becomes
adjacent.
adjacency address
An address that identifies a local subnet access point and a subnet address of an
adjacent system.
adjacent nodes
The nodes with direct lines between them; can communicate without an
intermediate system. For example, all nodes on an Ethernet LAN are adjacent
to each other.
administrative domain
A group of hosts, routers, and networks operated and managed by a single
organization. Routing within an administrative domain is based on a consistent
technical plan. An administrative domain is viewed from the outside, for purposes
of routing, as a cohesive entity, of which the internal structure is unimportant.
Information passed by other administrative domains is trusted less than
information from one’s own administrative domain.
advertisement lifetime
A field in the Router Discovery Protocol router advertisement message that
indicates how long advertisement addresses are valid. A lifetime of zero indicates
that one or more addresses are no longer valid.
aged packet
A data packet that is discarded because it exceeded the maximum number of hops
whilebeingforwardedthroughthenetwork.
agent
A system that acts on behalf of another system. (1) Client/server model: Part of the
system that initiates, prepares, and exchanges information preparation on behalf
Glossary–2