Gossip Protocol The nodes in the network communicate on an algorithm with the Bitcoind called the gossip protocol. When a block is completed, that block needs to be transmitted to the ledgers contained in each node, and that block has a certain identification number. One node will ask another node if it has that block, and if that node doesn‘t, then it will transfer that block for this new node to save. That node will then randomly select another block and find out if that node has the new information. It also does another thing. Once it has told the node its information, it asks that node if it has other new information and compares it to what it already has. If the information from the other node is not within its ledger, then it will take that information as well. That way there is a two-way exchange of information. Each node contacts six other nodes (in most cases that is true, but you can adjust your Bitcoind app to contact more nodes if you like). In most cases, nodes just contact six others at random. The node they choose is randomly selected and so, each time it opens a communication to a node, it is a different set of nodes. This keeps the system safe by not allowing predictability of who the node contacts are. If each contact six, then theoretically, it will only take six hops from any new piece of information originating from a node to reach all existing nodes. Think about it like this – the first node passes it to six nodes and each of them pass it to six more. That makes 36 nodes that are now up-to-date on that information which was broadcast by the first node. Those 36 then broadcast to six more which makes it 216. That‘s three jumps so far. From there, it becomes 1,296, and then 7,776 on the fifth hop. On the sixth hop, it becomes 46,656, but there are only 12,000 nodes at this point which means that it only takes a little over five hops to disseminate all the information of every transaction to the entire ecosystem. That happens in just a few seconds and everyone is up-to-date. The gossip protocol is extremely effective