Here’s a little something on networking, when the routing table changes it’s only because of a change in the topology of the network.

So if you send the id of the link that changed you can detect loops if a node gets the same update twice.

at a minimum if you only want the node that formed the loop to detect it then it can look if the node it’s routing says, “Hay I got a new distance to destination by going thou your link to me“

but to enable any node to detect loops to need more information than just the link ID as the link might change more than once. But that’s pretty much just Sequence Number from Destination-Sequenced Distance-Vector.

I still have to analyze this more to see if there is race condition in situations like:

An … A2, A1, destination, B1, B2 … Bn

then b1 changes it route to destination to go thru An and A1 changes it route to destination to go thru Bn before the other’s route update reaches them