NETGEAR GSM7252PS - ProSafe 52 Ports Gigabit Ethernet L2 Managed Stackable Switch User Manual page 282

ProSafe® Gigabit L3 Managed Stackable Switches Software Administration Manual
Table 32.
Field
State
Designated Router
Backup Designated Router
Other Designated Router
282 | Chapter 4. Routing
Description
The current state of the selected router interface.
One of:
• Down: This is the initial interface state. In this
state, the lower-level protocols have indicated that
the interface is unusable. In this state, interface
parameters will be set to their initial values. All
interface timers will be disabled, and there will be
no adjacencies associated with the interface.
•
Loopback: In this state, the router's interface to
the network is looped back either in hardware or
software. The interface is unavailable for regular
data traffic. However, it may still be desirable to
gain information on the quality of this interface,
either through sending ICMP pings to the interface
or through something like a bit error test. For this
reason, IP packets may still be addressed to an
interface in Loopback state. To facilitate this, such
interfaces are advertised in router- LSAs as single
host routes, whose destination is the IP interface
address.
•
Waiting: The router is trying to determine the
identity of the (Backup) Designated Router for the
network by monitoring received Hello Packets. The
router is not allowed to elect a Backup Designated
Router or a Designated Router until it transitions
out of Waiting state. This prevents unnecessary
changes of (Backup) Designated Router.
This router is itself the Designated Router on the
attached network. Adjacencies are established to all
other routers attached to the network. The router
must also originate a network-LSA for the network
node. The network- LSA will contain links to all
routers (including the Designated Router itself)
attached to the network.
This router is itself the Backup Designated Router on
the attached network. It will be promoted to
Designated Router if the present Designated Router
fails. The router establishes adjacencies to all other
routers attached to the network. The Backup
Designated Router performs slightly different
functions during the LSA flooding, as compared to
the Designated Router.
The interface is connected to a broadcast on which
other routers have been selected to be the
Designated Router and Backup Designated Router
either. The router attempts to form adjacencies to
both the Designated Router and the Backup
Designated Router.