Owner's Manual

Appendix E. Glossary | 923
NETGEAR 8800 User Manual
AS Autonomoous system. In OSPF, an AS is a connected segment of a network
topology that consists of a collection of subnetworks (with hosts attached)
interconnected by a set of routes. The subnetworks and the routers are
expected to be under the control of a single administration. Within an AS, routers
may use one or more interior routing protocols and sometimes several sets of
metrics. An AS is expected to present to other ASs an appearance of a coherent
interior routing plan and a consistent picture of the destinations reachable
through the AS. An AS is identified by a unique 16-bit number.
ASBR Autonomous system border router. In OSPF, an ASBR acts as a gateway
between OSPF and other routing protocols or other ASs.
autobind In STP, autobind, when enabled, automatically adds or removes ports from the
STPD. If ports are added to the carrier VLAN, the member ports of the VLAN are
automatically added to the STPD. If ports are removed from the carrier VLAN,
those ports are also removed from the STPD.
autonegotation As set forth in IEEE 802.3u, autonegotation allows each port on the switch—in
partnership with its link partner—to select the highest speed between 10 Mbps
and 100 Mbps and the best duplex mode.
B
backbone area In OSPF, a network that has more than one area must have a backbone area,
configured as 0.0.0.0. All areas in an AS must connect to the backbone area.
backup port In RSTP, the backup port supports the designated port on the same attached
LAN segment. Backup ports exist only when the bridge is connected as a
self-loop or to a shared media segment.
backup router In VRRP, the backup router is any VRRP router in the VRRP virtual router that is
not elected as the master. The backup router is available to assume forwarding
responsibility if the master becomes unavailable.
BDR Backup designated router. In OSPF, the system elects a DR and a BDR. The
BDR smooths the transition to the DR, and each multiaccess network has a
BDR. The BDR is adjacent to all routers on the network and becomes the DR
when the previous DR fails. The period of disruption in transit traffic lasts only as
long as it takes to flood the new LSAs (which announce the new DR). The BDR
is elected by the protocol; each hello packet has a field that specifies the BDR
for the network.
A (Continued)