From article:
https://github.com/bitcoin/bitcoin/issues/36041) are considering whether to retain support for CJDNS, an optional peer-to-peer transport. Ava Chow reported that a seeder database contained 25 CJDNS addresses, reached 22 of them, and classified seven as eligible nodes.
The seeder filter applies requirements stricter than simple reachability. To be classified as “good”, a node must pass checks on its port, advertised network service, protocol version, chain height, and reliability across multiple time windows. These criteria explain the difference between 22 reachable addresses and seven eligible nodes.
Bitcoin Core documentation already discourages exclusive use of CJDNS: a node may fail to fill its outbound connections, retry few known addresses, and face greater exposure to Sybil attacks. An “eclipse attack” isolates a node by monopolising the peers that determine its view of the network. Bitcoin Core normally maintains eight full-relay outbound connections and two block-relay-only connections, with occasional additional connections.
CJDNS 22.1 introduced auto-peering through DNS seeds on January 8, 2025. Bitcoin Core updated its configuration documentation on March 30, 2026, and on August 18, 2026 integrated a change that explicitly discourages exclusive CJDNS use. Any removal would concern address handling and connection options, not Bitcoin’s consensus rules or block-validity rules.