Sybex - CCNA 2.0 Study Guide (640-507).pdf - Cifo

680 Glossary
helper address The unicast address specified, which instructs the Cisco
router to change the client’s local broadcast request for a service into a
directed unicast to the server.
hierarchical addressing Any addressing plan employing a logical chain of
commands to determine location. IP addresses are made up of a hierarchy of
network numbers, subnet numbers, and host numbers to direct packets to
the appropriate destination.
HIP HSSI Interface Processor: An interface processor used on Cisco 7000
series routers, providing one HSSI port that supports connections to ATM,
SMDS, Frame Relay, or private lines at speeds up to T3 or E3.
holddown The state a route is placed in so that routers can neither advertise
the route nor accept advertisements about it for a defined time period.
Holddown is used to surface bad information about a route from all routers
in the network. A route is generally placed in holddown when one of its
links fails.
hop The movement of a packet between any two network nodes. See also:
hop count.
hop count A routing metric that calculates the distance between a source and
a destination. RIP employs hop count as its sole metric. See also: hop and RIP.
host address Logical address configured by an administrator or server on
a device. Logically identifies this device on an internetwork.
HSCI High-Speed Communication Interface: Developed by Cisco, a singleport
interface that provides full-duplex synchronous serial communications
capability at speeds up to 52Mbps.
HSRP Hot Standby Router Protocol: A protocol that provides high network
availability and provides nearly instantaneous hardware fail-over
without administrator intervention. It generates a Hot Standby router
group, including a lead router that lends its services to any packet being
transferred to the Hot Standby address. If the lead router fails, it will be
replaced by any of the other routers—the standby routers—that monitor it.
HSSI High-Speed Serial Interface: A network standard physical connector
for high-speed serial linking over a WAN at speeds of up to 52Mbps.