This section discusses some of the most common EIGRP errors that appear and
the meaning behind these EIGRP error messages.
DUAL-3-SIA
This message means that the primary route is gone and
no feasible successor is available. The router has sent out the queries to its
neighbor and has not heard the reply from a particular neighbor for more than
three minutes. The route state is now stuck in active state.
Neighbor is Not on Common Subnet
This message means that the
router has heard a hello packet from a neighbor that is not on the same subnet
as the router.
DUAL-3-BADCOUNT
Badcount means that EIGRP
believes that it knows of more routes for a given network than actually exists.
It is typically, but not always, seen in conjunction with DUAL-3-SIAs, but it
is not believed to cause any problems itself.
Unequal, <route>, dndb=<metric>,
query=<metric>
This message indicates that there is an EIGRP
internal error. However, the router is coded to fully recover from this
internal error. The EIGRP internal error is caused by a software problem and
should not affect the operation of the router.
IP-EIGRP: Callback:
callback_routes
At some point, EIGRP attempted to install routes to the
destinations and failed, most commonly because of the existence of a route with
a better administrative distance. When this occurs, EIGRP registers its route
as a backup route. When the better route disappears from the routing table,
EIGRP is called back through callback_routes so that it can attempt to
reinstall the routes that it is holding in the topology table.
Error:
EIGRP: DDB not Configured on Interface
This means that when the routers
interface receives an EIGRP hello packet and the router attempts to associate
the packet with a DUAL descriptor block (DDB) for that interface, it does not
find one that matches. This means that the router is receiving a hello packet
on the interface that does not have EIGRP configured.
Poison
Squashed
The router threads a topology table entry as poison in reply
to an update (the router set up for poison reverse). While the router is
building the packet that contains the poison reverse, the router realizes that
it does not need to send it. For example, if the router receives a query for
that route from the neighbor, it is currently threaded to poison.