By the time Satoshi answered Bohm’s question about his new router, Bohm had already written that he was connected again and that Satoshi could disregard it. Satoshi’s reply gave the advice anyway:
Satoshi Nakamoto (email to Nicholas Bohm, June 05, 2009, 8:40:00 PM UTC)You should set your router to forward port 8333 so you can receive incoming connections. If you’re not set up to receive incoming connections and nobody else who’s online is, then you can’t connect. It would also help solve the “(not accepted)” issues.
The middle sentence describes a network in which joining depended on luck: a node that could only dial out found a peer only if someone online happened to accept incoming connections. In mid-2009, nothing guaranteed that anyone did.
The last sentence tied the advice to a complaint Bohm had been making for weeks. Blocks he generated kept appearing as “Generated (not accepted)”, and on May 20 and again on June 2 he had sent Satoshi lists of them.
Satoshi’s own node had faced the same problem five months earlier, when he told Hal Finney he could not receive incoming connections from where he was.
This exchange stayed private until COPA v. Wright trial evidence revealed the full correspondence in 2024. Six weeks later, Bohm reported that his node had no connections at all.
Seventeen years later, half of the addresses at which Bitcoin nodes accept connections were Tor onions, which need no forwarded port at all (how half of Bitcoin’s reachable nodes came to be on Tor).
