4.3BSD routed "times out"

[narten at arthur.cs.purdue.edu.UUCP]

Routed increments timers for all routes. When the timer reaches a certain
value, the route is declared dead and removed from the kernel. This includes
routes for interfaces. 

The timers for interface routes are reset whenever a RIP packet comes in
over that interface. This can happen in one of two ways:

1) there is another router on that network broadcasting updates
2) it hears its own broadcast sent out over that interface.

If there is no other router on on the network that is timing out, then (1)
will never occur, and routed relies on (2). There is another catch, however.
When constructing the RIP packet to be sent out over an interface, only
routes for networks that are NOT routed over that interface are included.
The logic for this being that if we route to a net via interface A, some
other router on  net A is already advertising a better route than we could.

If you then have no nets to advertise, the packet never gets sent. Hence the
route times out. 

If your configuration consists of a single network, this is your problem.
In this case, there is also no need to run routed, as it doesn't really do
you any good.
-- 
Thomas Narten
narten at purdue.EDU or {ucbvax, ihnp4, allegra}!purdue!narten