CCNA Cisco Certified Network Associate Study Guide - FTP Server

702 Glossary
route poisoning Used by various DV routing protocols in order to overcome
large routing loops and offer explicit information about when a subnet
or network is not accessible (instead of merely suggesting that the network
is unreachable by not including it in updates). Typically, this is accomplished
by setting the hop count to one more than maximum. See also: poison
reverse updates.
route summarization In various routing protocols, such as OSPF,
EIGRP, and IS-IS, the consolidation of publicized subnetwork addresses so
that a single summary route is advertised to other areas by an area border
router.
router A Network-layer mechanism, either software or hardware, using
one or more metrics to decide on the best path to use for transmission of network
traffic. Sending packets between networks by routers is based on the
information provided on Network layers. Historically, this device has sometimes
been called a gateway.
routing The process of forwarding logically addressed packets from their
local subnetwork toward their ultimate destination. In large networks, the
numerous intermediary destinations a packet might travel before reaching its
destination can make routing very complex.
routing domain Any collection of end systems and intermediate systems
that operate under an identical set of administrative rules. Every routing
domain contains one or several areas, all individually given a certain area
address.
routing metric Any value that is used by routing algorithms to determine
whether one route is superior to another. Metrics include such information
as bandwidth, delay, hop count, path cost, load, MTU, reliability, and communication
cost. Only the best possible routes are stored in the routing table,
while all other information may be stored in link-state or topological databases.
See also: cost.
routing protocol Any protocol that defines algorithms to be used for
updating routing tables between routers. Examples include IGRP, RIP,
and OSPF.