User Manual

Routing
276
M6100 Web Management User Guide
State The current state of the selected router
interface.State is one of the following:
• 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.
• 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.
• Backup Designated Router — 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.
• Other 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.
Field Description