170
Summary
- // if you see it open
- No CVEs or notable incidents found tied to port 170/print-srv. Superseded by IPP (631), LPD (515), and JetDirect (9100) in modern printing; assessed as low-prevalence legacy service rather than confirmed-safe.
- // analyst note
- An open port 170 today is uncommon and most plausibly a legacy PostScript print service; no exposure/CVE data was found to elevate it above routine legacy-service triage.
About port 170/tcp.
Port 170/tcp is registered with IANA as print-srv, described as "Network PostScript," with assignee and contact both listed as [Brian_Reid] and a blank reference field. The same entry is dual-registered on 170/udp with identical service name, description, assignee, and contact, and neither the TCP nor UDP row carries a registration or modification date in either the cached registry CSV or the live IANA XML — this is consistent with a legacy, pre-2001-era assignment for which IANA never recorded a date field, so it is reported here as Unknown rather than guessed. print-srv designates a Network PostScript print-server protocol: a transport for streaming raw PostScript page-description data from a client to a PostScript-capable network printer or dedicated print-server daemon, in the tradition of early 1980s–1990s networked printing on Unix, Sun, and DEC-style systems. No RFC or other document is cited in the IANA reference column for this assignment, so none is asserted here. Modern network printing has largely superseded this model with IPP (port 631), LPD (port 515), and raw/JetDirect (port 9100), leaving 170/tcp a legacy, low-prevalence assignment; one undated archived nmap-services frequency table lists the udp sibling at an empirical open-frequency of roughly 0.001071, suggesting the family is rarely found open in broad internet scans, though a directly comparable tcp figure was not located. No CVEs, malware associations, or notable incidents tied specifically to port 170 or print-srv were found in this pass.
- IANA assignment
print-srv— "Network PostScript"; reference (blank — no RFC cited in IANA registry); assignee/contact [Brian_Reid]; dual-registered 170/tcp + 170/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry-418; https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml- Range class
- well-known (0–1023) [Confirmed]
- Registration/modification dates
- not present in the cached CSV or live IANA registry for this entry — Unknown, not fabricated [Confirmed absence] — the IANA Service Name and Transport Protocol Port Number Registry; https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xml
- Prevalence
- nmap-services open-frequency for 170/udp ≈ 0.001071 (undated archive mirror); a directly comparable 170/tcp figure was not located in this pass [Likely, single-source] — https://svn.nmap.org/nmap-exp/drazen/nmap-merge/nmap-services?p=29493
- Related ports
- modern printing protocols — IPP 631, LPD 515, raw/JetDirect 9100 [Confirmed — well-known assignments]
Primary use
Network PostScript print-server protocol — streaming PostScript data from client to network printer/print server; legacy, pre-IPP/pre-LPD era
Other/unofficial uses
no verifiable list of current software/hardware actively binding to 170/tcp today; historically associated with Unix/Sun/DEC-era PostScript print-server daemons
Security implications
no CVEs or notable incidents found tied to port 170/print-srv; assessed as low-relevance/legacy given superseding by IPP/LPD/JetDirect, but this is an absence-of-evidence finding, not a confirmed-safe verdict
Typically seen on
legacy PostScript-capable network printers; Unix/Sun/DEC-era print-server hosts [Likely]
- Analyst note
- An open port 170 today is uncommon and most plausibly a legacy PostScript print service; no exposure/CVE data was found to elevate it above routine legacy-service triage.
About port 170/udp.
Port 170/udp is registered with IANA as print-srv with the description "Network PostScript," assignee and contact [Brian_Reid], and a blank reference field — the registry cites no governing RFC for this assignment. The identical service name, description, and assignee also appear for 170/tcp, so the port is dual-registered on both transports rather than being a UDP-only assignment. Functionally, print-srv/Network PostScript is a legacy print-server protocol from the pre-IPP, pre-LPD era of network printing: it streamed raw PostScript page-description data from a client directly to a network-attached PostScript printer or a Unix/Sun print spooler, a model that predates and was largely displaced by LPD (515) and later IPP (631). No actively-maintained, currently-shipping software could be confirmed as still using this port, and no vendor product name surfaced in available sources — this reads as a dormant, historical assignment rather than a live service class. Security literature on the port is thin: one port-database aggregator reports no confirmed virus/trojan association, with an explicit caveat that this only reflects an absence of historically observed malware use rather than a safety guarantee, and no CVE or scanning-campaign data tied specifically to 170/udp was found. Given its age and low current relevance, an unexpectedly open 170/udp is more plausibly stale legacy printing infrastructure or a fingerprinting anomaly than an actively-exploited service.
- IANA assignment
print-srv— "Network PostScript"; reference (blank — no RFC cited in IANA registry); assignee/contact [Brian_Reid]; dual-registered 170/tcp + 170/udp [Confirmed] — the IANA Service Name and Transport Protocol Port Number Registry (line 418); https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=170- Range class
- well-known (0–1023) [Confirmed]
- Prevalence
- nmap-services observed open-frequency 170/udp ≈ 0.001071 — very low (roughly 1 in 1,000 sampled hosts), 327th of 5,615 UDP entries; the TCP sibling 170/tcp records 0. The figure measures how often the port answers a scan, not print-srv use [Likely] — nmap-services dataset
- Related ports
- 515/tcp (LPD, Line Printer Daemon), 631 (IPP, Internet Printing Protocol) — the network-printing protocols that largely superseded print-srv [Likely]
Primary use
legacy print-server protocol streaming raw PostScript data to network-attached PostScript printers/spoolers; predates and was largely superseded by LPD (515) and IPP (631)
Other/unofficial uses
no widely-documented, currently-maintained software confirmed to use 170/udp today; historical ties to 1990s-era Unix/Sun PostScript print spoolers
Security implications
minimal published literature; auditmypc.com lists no confirmed virus/trojan association, explicitly caveated as reflecting historical-observation absence rather than a safety guarantee; no CVE or malware family tied specifically to this port was found
Typically seen on
legacy Unix/Sun PostScript-based print spoolers and network-attached PostScript printers of the pre-IPP era; largely absent from modern deployments [Unknown]
- Analyst note
- a low-prevalence, dormant legacy assignment with a blank IANA reference and no confirmed current software; unexpected traffic on 170/udp warrants investigation as stale legacy printing infrastructure, a misconfiguration, or a fingerprinting/decoy anomaly rather than routine service traffic.
Service assignments.
| Name | Protocol | Description | Open frequency |
|---|---|---|---|
| print-srv | UDP | Network PostScript | 0.11% |
| print-srv | TCP | Network PostScript | 0.00% |
Service assignments from the IANA Service Name and Transport Protocol Port Number Registry, with open-frequency data from nmap-services.