Cabletron Systems CoreWatch, User Manual

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Glossary
474 CoreWatch User’s Manual
Autonomous System
A set of routers under a single technical administration, using an interior gateway
protocol and common metrics to route packets within the autonomous system, and using
an exterior gateway protocol to route packets to other autonomous systems.
Since this classic definition was developed, it has become common for a single
autonomous system to use several interior gateway protocols and sometimes several sets
of metrics within an autonomous system. The use of the term “autonomous system”
stresses that even when multiple IGPs and metrics are used, the administration of an
autonomous system appears to other autonomous systems to have a single coherent
interior routing plan and to present a consistent picture of what networks are reachable
through it.
Backup
Interface state that indicates a router is the backup designated router on the attached
network.
Backup Designated Router
OSPF router that will take over the functions of the designated router if that one fails. The
backup designated router establishes adjacencies to all other routers.
Boot Log
File containing the messages the SSR sends when starting up. You may want to examine
these messages to look at the configuration of the SSR and determine which functions
were online when you started the SSR.
Boundary Router
Router that exchanges routing information with routers belonging to other autonomous
systems. Such a router has autonomous system external routes that are advertised
throughout the autonomous system. The path to each autonomous system boundary
router is known by every router in the autonomous system.
This classification is completely independent of the other classifications; autonomous
system boundary routers may be internal or area border routers and may or may not
participate in the backbone.
Branch
Interface for which downstream neighbors exist.
Bridge Protocol Data Unit (BPDU)
Hello packet STP periodically sends to exchange information among bridges on a
network.
Broadcast
Packets sent to all of the nodes of a network.