Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-04-07
Expert(s)
TCP/UDP: Joe Touch; Eliot Lear, Kumiko Ono, Wes Eddy, Brian Trammell, 
Jana Iyengar, and Michael Scharf
SCTP: Michael Tuexen
DCCP: Eddie Kohler and Yoshifumi Nishida
Reference
[RFC6335]
Note
Service names and port numbers are used to distinguish between different
services that run over transport protocols such as TCP, UDP, DCCP, and
SCTP.

Service names are assigned on a first-come, first-served process, as
documented in [RFC6335].

Port numbers are assigned in various ways, based on three ranges: System
Ports (0-1023), User Ports (1024-49151), and the Dynamic and/or Private
Ports (49152-65535); the different uses of these ranges are described in
[RFC6335]. According to Section 8.1.2 of [RFC6335], System Ports are 
assigned by the "IETF Review" or "IESG Approval" procedures described in 
[RFC8126]. User Ports are assigned by IANA using the "IETF Review" process, 
the "IESG Approval" process, or the "Expert Review" process, as per 
[RFC6335]. Dynamic Ports are not assigned.

The registration procedures for service names and port numbers are
described in [RFC6335].

Assigned ports both System and User ports SHOULD NOT be used without
or prior to IANA registration.

************************************************************************
* PLEASE NOTE THE FOLLOWING:                                           *
*                                                                      *
* ASSIGNMENT OF A PORT NUMBER DOES NOT IN ANY WAY IMPLY AN             *
* ENDORSEMENT OF AN APPLICATION OR PRODUCT, AND THE FACT THAT NETWORK  *
* TRAFFIC IS FLOWING TO OR FROM A REGISTERED PORT DOES NOT MEAN THAT   *
* IT IS "GOOD" TRAFFIC, NOR THAT IT NECESSARILY CORRESPONDS TO THE     *
* ASSIGNED SERVICE. FIREWALL AND SYSTEM ADMINISTRATORS SHOULD          *
* CHOOSE HOW TO CONFIGURE THEIR SYSTEMS BASED ON THEIR KNOWLEDGE OF    *
* THE TRAFFIC IN QUESTION, NOT WHETHER THERE IS A PORT NUMBER          *
* REGISTERED OR NOT.                                                   *
************************************************************************

Request an Assignment
  [https://www.iana.org/protocols/apply]

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Service Name Port Number Transport Protocol Description Assignee Contact Registration Date Modification Date Reference Service Code Unauthorized Use Reported Assignment Notes
direct 242 udp Direct [Herb_Sutter] [Paul_Horton]
sur-meas 243 tcp Survey Measurement [Dave_Clark] [Dave_Clark]
sur-meas 243 udp Survey Measurement [Dave_Clark] [Dave_Clark]
inbusiness 244 tcp inbusiness [Derrick_Hisatake] [Derrick_Hisatake]
inbusiness 244 udp inbusiness [Derrick_Hisatake] [Derrick_Hisatake]
link 245 tcp LINK
link 245 udp LINK
dsp3270 246 tcp Display Systems Protocol [Weldon_J_Showalter] [Weldon_J_Showalter]
dsp3270 246 udp Display Systems Protocol [Weldon_J_Showalter] [Weldon_J_Showalter]
subntbcst-tftp 247 tcp SUBNTBCST_TFTP

IANA assigned this well-formed service name as a replacement for "subntbcst_tftp".
[John_Fake] [John_Fake]
subntbcst_tftp 247 tcp SUBNTBCST_TFTP [John_Fake] [John_Fake] This entry is an alias to "subntbcst-tftp". This entry is now historic, not usable for use with many common service discovery mechanisms.
subntbcst-tftp 247 udp SUBNTBCST_TFTP

IANA assigned this well-formed service name as a replacement for "subntbcst_tftp".
[John_Fake] [John_Fake]
subntbcst_tftp 247 udp SUBNTBCST_TFTP [John_Fake] [John_Fake] This entry is an alias to "subntbcst-tftp". This entry is now historic, not usable for use with many common service discovery mechanisms.
bhfhs 248 tcp bhfhs [John_Kelly] [John_Kelly]
bhfhs 248 udp bhfhs [John_Kelly] [John_Kelly]
249-255 Reserved 2024-12-20 [RFC1060]
bgmp 264 tcp BGMP [Dave_Thaler] [Dave_Thaler]
bgmp 264 udp BGMP [Dave_Thaler] [Dave_Thaler]
manet 269 tcp MANET Protocols [RFC5498]
manet 269 udp MANET Protocols [RFC5498]
corerjd 284 tcp corerjd [Chris_Thornhill] [Chris_Thornhill]
corerjd 284 udp corerjd [Chris_Thornhill] [Chris_Thornhill]
opalis-robot 314 tcp Opalis Robot [Laurent_Domenech] [Laurent_Domenech]
opalis-robot 314 udp Opalis Robot [Laurent_Domenech] [Laurent_Domenech]
rpki-rtr-tls 324 tcp Resource PKI to Router Protocol over TLS [IESG] [IETF_Chair] [RFC6810]
324 udp Reserved
334-343 Unassigned
pdap 344 tcp Prospero Data Access Protocol [B_Clifford_Neuman] [B_Clifford_Neuman]
pdap 344 udp Prospero Data Access Protocol [B_Clifford_Neuman] [B_Clifford_Neuman]
pawserv 345 tcp Perf Analysis Workbench
pawserv 345 udp Perf Analysis Workbench
zserv 346 tcp Zebra server
zserv 346 udp Zebra server
fatserv 347 tcp Fatmen Server
fatserv 347 udp Fatmen Server
csi-sgwp 348 tcp Cabletron Management Protocol
csi-sgwp 348 udp Cabletron Management Protocol
mftp 349 tcp mftp [Dave_Feinleib] [Dave_Feinleib]
mftp 349 udp mftp [Dave_Feinleib] [Dave_Feinleib]
bhoedap4 352 tcp bhoedap4 [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
bhoedap4 352 udp bhoedap4 [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
bh611 354 tcp bh611 [John_Kelly] [John_Kelly]
bh611 354 udp bh611 [John_Kelly] [John_Kelly]
aurora-cmgr 364 tcp Aurora CMGR [Philip_Budne] [Philip_Budne]
aurora-cmgr 364 udp Aurora CMGR [Philip_Budne] [Philip_Budne]
legent-2 374 tcp Legent Corporation [Keith_Boyce] [Keith_Boyce]
legent-2 374 udp Legent Corporation [Keith_Boyce] [Keith_Boyce]
arns 384 tcp A Remote Network Server System [David_Hornsby] [David_Hornsby]
arns 384 udp A Remote Network Server System [David_Hornsby] [David_Hornsby]
embl-ndt 394 tcp EMBL Nucleic Data Transfer [Peter_Gad] [Peter_Gad]
embl-ndt 394 udp EMBL Nucleic Data Transfer [Peter_Gad] [Peter_Gad]
osb-sd 400 tcp Oracle Secure Backup [Steven_Wertheimer] [Steven_Wertheimer] 2008-06-06 2023-12-27 Formerly was Workstation Solutions
osb-sd 400 udp Oracle Secure Backup [Steven_Wertheimer] [Steven_Wertheimer] 2008-06-06 2023-12-27 Formerly was Workstation Solutions
ups 401 tcp Uninterruptible Power Supply [Charles_Bennett] [Charles_Bennett] 2008-08-29
ups 401 udp Uninterruptible Power Supply [Charles_Bennett] [Charles_Bennett] 2008-08-29
genie 402 tcp Genie Protocol [Mark_Hankin] [Mark_Hankin]
genie 402 udp Genie Protocol [Mark_Hankin] [Mark_Hankin]
decap 403 tcp decap
decap 403 udp decap
nced 404 tcp nced
nced 404 udp nced
ncld 405 tcp ncld [Richard_Jones] [Richard_Jones]
ncld 405 udp ncld [Richard_Jones] [Richard_Jones]
imsp 406 tcp Interactive Mail Support Protocol [John_Myers] [John_Myers]
imsp 406 udp Interactive Mail Support Protocol [John_Myers] [John_Myers]
timbuktu 407 tcp Timbuktu [Marc_Epard] [Marc_Epard]
timbuktu 407 udp Timbuktu [Marc_Epard] [Marc_Epard]
prm-sm 408 tcp Prospero Resource Manager Sys. Man.
prm-sm 408 udp Prospero Resource Manager Sys. Man.
prm-nm 409 tcp Prospero Resource Manager Node Man. [B_Clifford_Neuman] [B_Clifford_Neuman]
prm-nm 409 udp Prospero Resource Manager Node Man. [B_Clifford_Neuman] [B_Clifford_Neuman]
decladebug 410 tcp DECLadebug Remote Debug Protocol [Hewlett_Packard] [Hewlett_Packard]
decladebug 410 udp DECLadebug Remote Debug Protocol [Hewlett_Packard] [Hewlett_Packard]
rmt 411 tcp Remote MT Protocol [Peter_Eriksson] [Peter_Eriksson]
rmt 411 udp Remote MT Protocol [Peter_Eriksson] [Peter_Eriksson]
synoptics-trap 412 tcp Trap Convention Port [Illan_Raab] [Illan_Raab]
synoptics-trap 412 udp Trap Convention Port [Illan_Raab] [Illan_Raab]
smsp 413 tcp Storage Management Services Protocol [Murthy_Srinivas] [Murthy_Srinivas]
smsp 413 udp Storage Management Services Protocol [Murthy_Srinivas] [Murthy_Srinivas]
infoseek 414 tcp InfoSeek [Steve_Kirsch] [Steve_Kirsch]
infoseek 414 udp InfoSeek [Steve_Kirsch] [Steve_Kirsch]
bnet 415 tcp BNet [Jim_Mertz] [Jim_Mertz]
bnet 415 udp BNet [Jim_Mertz] [Jim_Mertz]
silverplatter 416 tcp Silverplatter [Peter_Ciuffetti] [Peter_Ciuffetti]
silverplatter 416 udp Silverplatter [Peter_Ciuffetti] [Peter_Ciuffetti]
onmux 417 tcp Onmux [Stephen_Hanna] [Stephen_Hanna]
onmux 417 udp Onmux [Stephen_Hanna] [Stephen_Hanna]
hyper-g 418 tcp Hyper-G [Frank_Kappe] [Frank_Kappe]
hyper-g 418 udp Hyper-G [Frank_Kappe] [Frank_Kappe]
ariel1 419 tcp Ariel 1 [Joel_Karafin] [Joel_Karafin]
ariel1 419 udp Ariel 1 [Joel_Karafin] [Joel_Karafin]
smpte 420 tcp SMPTE [Si_Becker] [Si_Becker]
smpte 420 udp SMPTE [Si_Becker] [Si_Becker]
ariel2 421 tcp Ariel 2
ariel2 421 udp Ariel 2
ariel3 422 tcp Ariel 3 [Joel_Karafin] [Joel_Karafin]
ariel3 422 udp Ariel 3 [Joel_Karafin] [Joel_Karafin]
opc-job-start 423 tcp IBM Operations Planning and Control Start
opc-job-start 423 udp IBM Operations Planning and Control Start
opc-job-track 424 tcp IBM Operations Planning and Control Track [Conny_Larsson] [Conny_Larsson]
opc-job-track 424 udp IBM Operations Planning and Control Track [Conny_Larsson] [Conny_Larsson]

Contact Information

ID Name Organization Contact URI Last Updated
[B_Clifford_Neuman] B. Clifford Neuman mailto:bcn&isi.edu 2022-02-18
[Charles_Bennett] Charles Bennett mailto:bennettc&ohio.edu 2008-08-29
[Chris_Thornhill] Chris Thornhill mailto:port_contact&cjt.ca
[Conny_Larsson] Conny Larsson mailto:cocke&vnet.ibm.com
[Dave_Clark] Dave Clark mailto:ddc&lcs.mit.edu
[Dave_Feinleib] Dave Feinleib mailto:davefe&microsoft.com
[Dave_Thaler] Dave Thaler mailto:dave.thaler.ietf&gmail.com 2024-07-23
[David_Hornsby] David Hornsby mailto:djh&munnari.oz.au
[Derrick_Hisatake] Derrick Hisatake mailto:derrick.i.hisatake&intel.com
[Frank_Kappe] Frank Kappe mailto:fkappe&iicm.tu-graz.ac.at
[Herb_Sutter] Herb Sutter mailto:HerbS&cntc.com
[Hewlett_Packard] Hewlett Packard
[IESG] IESG mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org
[Illan_Raab] Illan Raab mailto:iraab&synoptics.com
[Jim_Mertz] Jim Mertz mailto:JMertz+RV09&rvdc.unisys.com
[Joel_Karafin] Joel Karafin mailto:jkarafin&infotrieve.com
[John_Fake] John Fake mailto:fake&us.ibm.com
[John_Kelly] John Kelly mailto:johnk&bellhow.com
[John_Myers] John Myers mailto:jgm+&cmu.edu
[Keith_Boyce] Keith Boyce
[Laurent_Domenech] Laurent Domenech Opalis mailto:ldomenech&opalis.com
[Marc_Epard] Marc Epard mailto:marc&netopia.com
[Mark_Hankin] Mark Hankin
[Murthy_Srinivas] Murthy Srinivas mailto:murthy&novell.com
[Paul_Horton] Paul Horton mailto:paul.horton&dxstro.com 2016-05-18
[Peter_Ciuffetti] Peter Ciuffetti mailto:petec&silverplatter.com
[Peter_Eriksson] Peter Eriksson mailto:pen&lysator.liu.se
[Peter_Gad] Peter Gad mailto:peter&bmc.uu.se
[Philip_Budne] Philip Budne mailto:budne&auroratech.com
[Richard_Jones] Richard Jones
[Si_Becker] Si Becker mailto:71362.22&compuserve.com
[Stephen_Hanna] Stephen Hanna mailto:hanna&world.std.com
[Steve_Kirsch] Steve Kirsch mailto:stk&infoseek.com
[Steven_Wertheimer] Steven Wertheimer mailto:steven.wertheimer&oracle.com 2023-12-27
[Weldon_J_Showalter] Weldon J. Showalter mailto:Gamma&mintaka.dca.mil