2
There is a 2016 paper from Bitfury on a proposed routing algorithm for LN:
Flare: An Approach to Routing in Lightning Network
What is the relation between it and was was actually implemented (the primary reference being the BOLT specs)?
Routing for Lightning network: was Flare implemented?
Answers
2
As far as I know flare was never implemented for lightning nodes and is not being used. I think current implementations use sind pathfinding algorithms like BfS or Dijkstra. The pathfinding itself is not part of the BOLTs anyway. A node could do whatever it wants with the information provided from the gossip store / gossip protocol. (BOLT 07). People could in particular decide to go for the approach given by flare.
1It was implemented by Bitfury and Acinq, but only for testing purposes, it never went to the production implementation. – Dmitry Laptev – 2019-03-16T20:29:36.663