34

Port 34/tcp is Unassigned in IANA's Service Name and Transport Protocol Port Number Registry: the registry row carries no service name, no assignee, no registration or modification date, and a blank Reference column, with the description field reading simply "Unassigned." The same is true of 34/udp, so the number is unallocated across both transport protocols. There is no RFC that governs this port, and Wikipedia's list of well-known ports skips 34 entirely, stepping from port 33 (Display Support Protocol) to port 37 (Time Protocol) — a useful tell that no widely recognized service ever claimed it. Because the number sits in the well-known range (0–1023) yet has no official owner, it is one of the relatively rare low-numbered ports that an analyst will essentially never expect to see open on a legitimately configured internet-facing host. Empirically it is almost absent from the wild: the nmap-services database lists 34/tcp as unknown with an open-port frequency of roughly 0.000025, derived from Nmap's internet scan data — about as close to "never observed open" as the dataset records. There is no documented mainstream software that defaults to this port, no curated malware signature tied specifically to it, and no public CVE or threat-actor campaign naming 34/tcp as of June 2026. The practical analyst takeaway is that an open 34/tcp has no benign default explanation: any service answering on it is a custom or proprietary application, a misconfiguration, or potentially malicious — an unassigned well-known port found listening is worth investigating rather than dismissing, even though the port itself has no inherent vulnerability. As with every unassigned number, the honest characterization is the absence of an assignment, not the presence of a hidden purpose.

IANA assignment

none — 34/tcp is Unassigned; service name, assignee, dates, and Reference column are all blank in the registry [IANA-assigned] — IANA Service Name and Transport Protocol Port Number Registry

Range class

well-known (0–1023)

Prevalence

nmap-services labels 34/tcp unknown with open-frequency ≈ 0.000025 (near-zero; rarely found open) [Well-established] — nmap-services file

Related ports

neighboring well-known numbers 33/tcp (Display Support Protocol, dsp) and 37/tcp (Time Protocol); the unassigned-port class generally

Dual registration

34/udp is likewise Unassigned [IANA-assigned] — IANA registry

Primary use

none registered; no RFC governs port 34; Wikipedia's well-known ports list skips it

Other/unofficial uses

Unknown — no widely documented software claims 34/tcp as a default or well-known port [Unknown]

Security implications

no assigned protocol and negligible internet exposure; because the port is unassigned and almost never open legitimately, any externally reachable service on it warrants investigation (unassigned well-known ports found open often indicate backdoors, port-knocking, or operator error). No CVE or threat-actor campaign specific to 34/tcp found in public sources as of June 2026

Typically seen on

nothing by default; an open 34/tcp is an anomaly / possible custom app, misconfiguration, or backdoor

Analyst note

An open 34/tcp has no benign default explanation; treat a listener as anomalous and investigate. The port has no inherent vulnerability — the signal is that nothing standard should be there.

Port 34/udp is listed as Unassigned in the IANA Service Name and Transport Protocol Port Number Registry: the registry row for 34/udp carries a blank service name, blank assignee, blank contact, blank reference, and no registration or modification date, and the companion 34/tcp row is identically Unassigned — so this is a well-known-range (0–1023) number that IANA has never formally allocated. Third-party port databases (for example WhatPortIs and SpeedGuide) instead label port 34 with the informal name "Remote File (RF)," describing an early, unauthenticated remote file read/write service that predated FTP, SFTP, and SMB and could run over UDP when speed was favored over reliability. That label has no first-party provenance: no RFC formally specifies a Remote File protocol on port 34 (RFC 217 surfaces in searches but is unrelated, covering RJE/RJOR work at UCSB), and no surviving IETF or IANA specification document for the assignment was located. The protocol is therefore best treated as obsolete folklore rather than a live service. For an analyst, an open 34/udp warrants the usual caution applied to any unassigned UDP port: there is no standardized service to expect, no widely cited internet-wide scan signal for it (public Shodan results were not retrievable unauthenticated, and no CVE or SANS ISC diary targeting the port was found), and any process answering on it should be investigated on its own merits rather than assumed to be the historical RF service. Because the original RF design had no authentication, any genuine residual instance would be inherently insecure, but real-world prevalence appears negligible. Wikipedia's List of TCP and UDP port numbers omits port 34 entirely, skipping from 33 (Display Support Protocol) to 37 (Time Protocol).

IANA assignment

Unassigned — blank service name, blank assignee, blank contact, blank reference; no RFC cited; 34/tcp identically Unassigned [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry line 76 (and line 75 for tcp); https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=34

Range class

well-known (0–1023)

IANA service name

none (Unassigned as of June 2026) [Confirmed] — https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=34

Prevalence / exposure

low; no widely cited internet-wide scan signal; Shodan public results not retrievable unauthenticated; no CVE or SANS ISC diary found targeting 34/udp [Likely] — https://whatportis.com/ports/34_remote-file-rf, https://nmap.org/book/scan-methods-udp-scan.html

Related ports

34/tcp (also Unassigned); contrast standardized file-transfer ports (20/21 FTP, 22 SFTP, 445 SMB)

Common software

none identified using 34/udp; third-party sources speculate legacy embedded/emulation use but name no products or versions

Security implications

original RF design lacked authentication, so any residual open instance is inherently insecure, but practical risk is negligible given near-zero modern deployment; not a known active scanning target

Typically seen on

nothing standard; an open 34/udp is an anomaly to investigate on its own merits

Historical/unofficial name

"Remote File (RF)" — third-party port databases only; early unauthenticated remote file read/write service predating FTP/SFTP/SMB, could use UDP for speed over reliability [Likely] — https://whatportis.com/ports/34_remote-file-rf

RFC reference

none found; no RFC specifies a Remote File protocol on port 34 (RFC 217 is unrelated — RJE/RJOR at UCSB) [Confirmed] — https://datatracker.ietf.org/doc/html/rfc217

Wikipedia status

no entry — the well-known ports table skips from 33 (Display Support Protocol) to 37 (Time Protocol) [Confirmed] — https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

Analyst note

IANA-Unassigned; the "Remote File (RF)" label is third-party folklore with no RFC or IANA provenance. Treat an open 34/udp as unidentified — investigate the listening process directly.