Lightning nodes must know which channels exist and their respective capacities to route payments effectively. Rather than relying on a central server, LN uses a gossip protocol: nodes announce their channels and state changes (like capacity updates) to peers, who relay this data further. This decentralized approach ensures no single point of failure for LN topology.

Too much gossip can overload the network, so LN implementations optimize what’s shared and how often. The result is a collectively maintained network graph, letting nodes find payment routes. If a route fails mid-payment, the node learns and adjusts for future attempts. Gossip is essential to LN’s peer-to-peer nature, keeping the network up to date without centralized oversight.