BIP95: Change default P2P port to 18353 #2346

Bitcoin Core gives each network three consecutive ports for RPC, P2P and onion, in that order. Mainnet uses 8332/8333/8334 for example, Testnet 3 18332/18333/18334 etc. bitcoin/bitcoin#35861 (and BIP 95) originally used 18334/18335/18336, which put its RPC port on Testnet 3's onion port as came up in review.

The PR now uses 18352/18353/18354 and allows to keep the RPC/P2P/onion order. Testnet 3's P2P port 18333 can be read as 183N3 with N = 3. Testnet 5 would use N = 5. This logic leaves room to continue with 18363 and up if another testnet is ever needed.

This updates the P2P port in the BIP to 18353. I think changing it now is fine. The genesis block isn't mined yet, and the Core PR is the only implementation with the Genesis block not being mined yet, so no additional work is needed to adapt to this.

ACK

Perhaps bump the Version header to 0.1.1 and add a changelog entry for the port change?

The Reference Implementation still says “Pull request at ?” — at some point could be updated to link to https://github.com/bitcoin/bitcoin/pull/35861 when merged or closer to it.

Thanks for the feedback!

Perhaps bump the Version header to 0.1.1 and add a changelog entry for the port change?

Done, makes sense and I even went with 0.2.0 for the version. It's actually a real implementation change rather than a bug fix so it seemed more appropriate for the bump.

The Reference Implementation still says "Pull request at ?"

Added the link to bitcoin/bitcoin#35861.

ACK ab3f20041fd70f0cf354c5a5775fc5b34e1093ea

:)

ACK, thanks for updating