The Gnutella peer-to-peer network's default port, TCP and UDP 6346.
IANA registers 6346 as gnutella-svc for both TCP and UDP, and it is the default listening port for Gnutella servents — historically LimeWire, BearShare and Shareaza, still gtk-gnutella today. TCP carries peer connections and file transfers; UDP carries out-of-band query replies and host-cache pings in the modern protocol. Because peers must accept inbound connections to be useful, this port is deliberately opened or UPnP-forwarded, and it lit up firewall logs constantly during the file-sharing era. Finding it on a corporate network is normally a policy question about P2P clients rather than a compromise.
Expose with care
Gnutella is designed to be internet-facing — an unreachable peer is a degraded peer — so exposing it can be deliberate. The exposure is what the client shares and the fact that an open 6346 advertises this host as a P2P node: audit the shared folders, and expose it only where that is fine.
$ sudo lsof -nP -iTCP:6346 -sTCP:LISTENSeen this on your network? Beige Box scans your Wi-Fi and shows every open port on every device — and its Ports tool links straight back here.
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Corrections or a missing port? Reply @rimrocksystems.