And there comes nice feature of ampr-ripd program by Marius YO2LOJ:
in case of missing or not broadcasted RIPv4 transmission, it keeps LASTLY received data, thus preserving routing table.
But of course only for completely lost transmissions. Some time ago I was hunting a problem where I apparently had packet loss in RIP transmissions, likely because they are sent in a big burst and may overflow buffers or exceed rate limits somewhere. In that case I was randomly losing routes. I kind of fixed that by increasing the timeout on routes to two hours (default was much lower, 15 minutes I think).
Also when something would break down that resulted in e.g. the RIP server sending only info about 44.0.0.0/8 in a single packet and not all the other gateways (e.g. due to an empty result from a database query due to some outside issue), the routes would still be lost. It is always difficult to prevent all possible mishaps. Sending updates from different sources will also not prevent all problems (after all there must be a single source of all the info that is being distributed, or we would be faced with two portal systems and the obligation to always register and update both).
Rob