Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2025-08-07
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
dn6-nlm-aud 195 udp DNSIX Network Level Module Audit
dn6-smm-red 196 udp DNSIX Session Mgt Module Audit Redir [Lawrence_Lebahn] [Lawrence_Lebahn]
dls 197 udp Directory Location Service
dls-mon 198 udp Directory Location Service Monitor [Scott_Bellew] [Scott_Bellew]
smux 199 udp SMUX [Marshall_Rose] [Marshall_Rose]
src 200 udp IBM System Resource Controller [Gerald_McBrearty] [Gerald_McBrearty]
at-rtmp 201 udp AppleTalk Routing Maintenance
at-nbp 202 udp AppleTalk Name Binding
at-3 203 udp AppleTalk Unused
at-echo 204 udp AppleTalk Echo
at-5 205 udp AppleTalk Unused
at-zis 206 udp AppleTalk Zone Information
at-7 207 udp AppleTalk Unused
at-8 208 udp AppleTalk Unused [Rob_Chandhok] [Rob_Chandhok]
qmtp 209 udp The Quick Mail Transfer Protocol [D_J_Bernstein] [D_J_Bernstein] 2018-04-05
z39-50 210 udp ANSI Z39.50

IANA assigned this well-formed service name as a replacement for "z39.50".
[Mark_H_Needleman] [Mark_H_Needleman]
z39.50 210 udp ANSI Z39.50 [Mark_H_Needleman] [Mark_H_Needleman] This entry is an alias to "z39-50". This entry is now historic, not usable for use with many common service discovery mechanisms.
914c-g 211 udp Texas Instruments 914C/G Terminal

IANA assigned this well-formed service name as a replacement for "914c/g".
[Bill_Harrell] [Bill_Harrell]
914c/g 211 udp Texas Instruments 914C/G Terminal [Bill_Harrell] [Bill_Harrell] This entry is an alias to "914c-g". This entry is now historic, not usable for use with many common service discovery mechanisms.
anet 212 udp ATEXSSTR [Jim_Taylor] [Jim_Taylor]
ipx 213 udp IPX [Don_Provan] [Don_Provan]
vmpwscs 214 udp VM PWSCS [Dan_Shia] [Dan_Shia]
softpc 215 udp Insignia Solutions [Martyn_Thomas] [Martyn_Thomas]
CAIlic 216 udp Computer Associates Int'l License Server [Chuck_Spitz] [Chuck_Spitz]
dbase 217 udp dBASE Unix [Don_Gibson] [Don_Gibson]
mpp 218 udp Netix Message Posting Protocol [Shannon_Yeh] [Shannon_Yeh]
uarps 219 udp Unisys ARPs [Ashok_Marwaha] [Ashok_Marwaha]
imap3 220 udp Interactive Mail Access Protocol v3 [James_Rice] [James_Rice]
fln-spx 221 udp Berkeley rlogind with SPX auth
rsh-spx 222 udp Berkeley rshd with SPX auth
cdc 223 udp Certificate Distribution Center [Kannan_Alagappan] [Kannan_Alagappan]
masqdialer 224 udp masqdialer [Charles_Wright] [Charles_Wright] Possible Conflict of Port 222 with "Masqdialer"
direct 242 udp Direct [Herb_Sutter] [Paul_Horton]
sur-meas 243 udp Survey Measurement [Dave_Clark] [Dave_Clark]
inbusiness 244 udp inbusiness [Derrick_Hisatake] [Derrick_Hisatake]
link 245 udp LINK
dsp3270 246 udp Display Systems Protocol [Weldon_J_Showalter] [Weldon_J_Showalter]
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 udp bhfhs [John_Kelly] [John_Kelly]
rap 256 udp RAP [J_S_Greenfield] [J_S_Greenfield]
set 257 udp Secure Electronic Transaction [Donald_Eastlake] [Donald_Eastlake]
esro-gen 259 udp Efficient Short Remote Operations [Mohsen_Banan] [Mohsen_Banan]
openport 260 udp Openport [John_Marland] [John_Marland]
nsiiops 261 udp IIOP Name Service over TLS/SSL [Jeff_Stewart] [Jeff_Stewart]
arcisdms 262 udp Arcisdms [Russell_Crook] [Russell_Crook]
hdap 263 udp HDAP [Troy_Gau] [Troy_Gau]
bgmp 264 udp BGMP [Dave_Thaler] [Dave_Thaler]
x-bone-ctl 265 udp X-Bone CTL [Joe_Touch] [Joe_Touch]
sst 266 udp SCSI on ST [Donald_D_Woelz] [Donald_D_Woelz]
td-service 267 udp Tobit David Service Layer
td-replica 268 udp Tobit David Replica [Franz_Josef_Leuders] [Franz_Josef_Leuders]
manet 269 udp MANET Protocols [RFC5498]
gist 270 udp Q-mode encapsulation for GIST messages [RFC5971]
271 udp Reserved
http-mgmt 280 udp http-mgmt [Adrian_Pell] [Adrian_Pell]
personal-link 281 udp Personal Link [Dan_Cummings] [Dan_Cummings]
cableport-ax 282 udp Cable Port A/X [Craig_Langfahl] [Craig_Langfahl]
rescap 283 udp rescap [Paul_Hoffman] [Paul_Hoffman]
corerjd 284 udp corerjd [Chris_Thornhill] [Chris_Thornhill]
fxp 286 udp FXP Communication [James_Darnall] [James_Darnall]
k-block 287 udp K-BLOCK [Simon_P_Jackson] [Simon_P_Jackson]
300 udp Reserved
novastorbakcup 308 udp Novastor Backup [Brian_Dickman] [Brian_Dickman]
entrusttime 309 udp EntrustTime [Peter_Whittaker] [Peter_Whittaker]
bhmds 310 udp bhmds [John_Kelly] [John_Kelly]
asip-webadmin 311 udp AppleShare IP WebAdmin [Ann_Huang] [Ann_Huang]
vslmp 312 udp VSLMP [Gerben_Wierda] [Gerben_Wierda]
magenta-logic 313 udp Magenta Logic [Karl_Rousseau] [Karl_Rousseau]
opalis-robot 314 udp Opalis Robot [Laurent_Domenech] [Laurent_Domenech]
dpsi 315 udp DPSI [Tony_Scamurra] [Tony_Scamurra]
decauth 316 udp decAuth [Michael_Agishtein] [Michael_Agishtein]
zannet 317 udp Zannet [Zan_Oliphant] [Zan_Oliphant]
pkix-timestamp 318 udp PKIX TimeStamp [Robert_Zuccherato] [Robert_Zuccherato]
ptp-event 319 udp PTP Event [Kang_Lee] [Kang_Lee] 2010-07-27
ptp-general 320 udp PTP General [Kang_Lee] [Kang_Lee] 2010-07-27
pip 321 udp PIP [Gordon_Mohr] [Gordon_Mohr]
rtsps 322 udp RTSPS [Anders_Klemets] [Anders_Klemets]
323 udp Reserved
324 udp Reserved
texar 333 udp Texar Security Port [Eugen_Bacic] [Eugen_Bacic]
pdap 344 udp Prospero Data Access Protocol [B_Clifford_Neuman] [B_Clifford_Neuman]
pawserv 345 udp Perf Analysis Workbench
zserv 346 udp Zebra server
fatserv 347 udp Fatmen Server
csi-sgwp 348 udp Cabletron Management Protocol
mftp 349 udp mftp [Dave_Feinleib] [Dave_Feinleib]
matip-type-a 350 udp MATIP Type A [Alain_Robert] [Alain_Robert] [RFC2351]
matip-type-b 351 udp MATIP Type B [Alain_Robert] [Alain_Robert] [RFC2351]
bhoetty 351 udp bhoetty [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
dtag-ste-sb 352 udp DTAG [Ruediger_Wald] [Ruediger_Wald] (assigned long ago)
bhoedap4 352 udp bhoedap4 [John_Kelly] [John_Kelly] This entry records an unassigned but widespread use (added 5/21/97)
ndsauth 353 udp NDSAUTH [Jayakumar_Ramalingam] [Jayakumar_Ramalingam]
bh611 354 udp bh611 [John_Kelly] [John_Kelly]
datex-asn 355 udp DATEX-ASN [Kenneth_Vaughn] [Kenneth_Vaughn]
cloanto-net-1 356 udp Cloanto Net 1 [Michael_Battilana] [Michael_Battilana] 2010-04-30
bhevent 357 udp bhevent [John_Kelly] [John_Kelly]
shrinkwrap 358 udp Shrinkwrap [Bill_Simpson] [Bill_Simpson]
359 udp Reserved 2023-11-16 De-Assigned on 2023-11-16.
scoi2odialog 360 udp scoi2odialog [Keith_Petley] [Keith_Petley]
semantix 361 udp Semantix [Semantix] [Semantix]

Contact Information

ID Name Organization Contact URI Last Updated
[Adrian_Pell] Adrian Pell mailto:PELL_ADRIAN/HP-UnitedKingdom_om6@hplb.hpl.hp.com
[Alain_Robert] Alain Robert mailto:arobert&par.sita.int
[Anders_Klemets] Anders Klemets mailto:anderskl&microsoft.com
[Ann_Huang] Ann Huang mailto:annhuang&apple.com
[Ashok_Marwaha] Ashok Marwaha
[B_Clifford_Neuman] B. Clifford Neuman mailto:bcn&isi.edu 2022-02-18
[Bill_Harrell] Bill Harrell
[Bill_Simpson] Bill Simpson mailto:wsimpson&greendragon.com
[Brian_Dickman] Brian Dickman mailto:brian&novastor.com
[Charles_Wright] Charles Wright mailto:cpwright&villagenet.com
[Chris_Thornhill] Chris Thornhill mailto:port_contact&cjt.ca
[Chuck_Spitz] Chuck Spitz mailto:spich04&cai.com
[Craig_Langfahl] Craig Langfahl mailto:Craig_J_Langfahl&ccm.ch.intel.com
[D_J_Bernstein] D. J. Bernstein mailto:ports&box.cr.yp.to 2018-04-05
[Dan_Cummings] Dan Cummings mailto:doc&cnr.com
[Dan_Shia] Dan Shia mailto:dset!shia&uunet.uu.net
[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
[Derrick_Hisatake] Derrick Hisatake mailto:derrick.i.hisatake&intel.com
[Don_Gibson] Don Gibson mailto:sequent!aero!twinsun!ashtate.A-T.COM!dong&uunet.UU.NET
[Don_Provan] Don Provan mailto:donp&xlnvax.novell.com
[Donald_D_Woelz] Donald D. Woelz mailto:don&genroco.com
[Donald_Eastlake] Donald Eastlake mailto:d3e3e3&gmail.com
[Eugen_Bacic] Eugen Bacic mailto:ebacic&texar.com
[Franz_Josef_Leuders] Franz-Josef Leuders mailto:development&tobit.com
[Gerald_McBrearty] Gerald McBrearty
[Gerben_Wierda] Gerben Wierda mailto:Gerben_Wierda&rna.nl
[Gordon_Mohr] Gordon Mohr mailto:gojomo&usa.net
[Herb_Sutter] Herb Sutter mailto:HerbS&cntc.com
[J_S_Greenfield] J. S. Greenfield mailto:greeny&raleigh.ibm.com
[James_Darnall] James Darnall mailto:james_r_darnall&sbcglobal.net
[James_Rice] James Rice mailto:RICE&sumex-aim.stanford.edu
[Jayakumar_Ramalingam] Jayakumar Ramalingam mailto:jayakumar&novell.com
[Jeff_Stewart] Jeff Stewart mailto:jstewart&netscape.com
[Jim_Taylor] Jim Taylor mailto:taylor&heart.epps.kodak.com
[Joe_Touch] Joe Touch mailto:touch&strayalpha.com 2020-02-07
[John_Fake] John Fake mailto:fake&us.ibm.com
[John_Kelly] John Kelly mailto:johnk&bellhow.com
[John_Marland] John Marland mailto:jmarland&dean.openport.com
[Kang_Lee] Kang Lee I&M Society TC-9 mailto:kang.lee&nist.gov 2010-07-27
[Kannan_Alagappan] Kannan Alagappan mailto:kannan&sejour.enet.dec.com
[Karl_Rousseau] Karl Rousseau mailto:kr&netfusion.co.uk
[Keith_Petley] Keith Petley mailto:keithp&sco.com
[Kenneth_Vaughn] Kenneth Vaughn mailto:kvaughn&mail.viggen.com
[Laurent_Domenech] Laurent Domenech Opalis mailto:ldomenech&opalis.com
[Lawrence_Lebahn] Lawrence Lebahn mailto:DIA3&paxrv-nes.navy.mil
[Mark_H_Needleman] Mark H. Needleman mailto:markn&sirsi.com
[Marshall_Rose] Marshall Rose mailto:mrose17&gmail.com 2024-07-29
[Martyn_Thomas] Martyn Thomas
[Michael_Agishtein] Michael Agishtein mailto:misha&unx.dec.com
[Michael_Battilana] Michael Battilana mailto:mcb-iana&cloanto.net 2010-04-30
[Mohsen_Banan] Mohsen Banan mailto:mohsen&rostam.neda.com
[Paul_Hoffman] Paul Hoffman mailto:phoffman&proper.com 2024-07-23
[Paul_Horton] Paul Horton mailto:paul.horton&dxstro.com 2016-05-18
[Peter_Whittaker] Peter Whittaker mailto:pww&entrust.com
[Rob_Chandhok] Rob Chandhok mailto:chandhok&gnome.cs.cmu.edu
[Robert_Zuccherato] Robert Zuccherato mailto:robert.zuccherato&entrust.com
[Ruediger_Wald] Ruediger Wald mailto:wald&ez-darmstadt.telekom.de
[Russell_Crook] Russell Crook mailto:rmc&sni.ca
[Scott_Bellew] Scott Bellew mailto:smb&cs.purdue.edu
[Semantix] Semantix mailto:xsSupport&semantix.com
[Shannon_Yeh] Shannon Yeh mailto:yeh&netix.com
[Simon_P_Jackson] Simon P Jackson mailto:jacko&kring.co.uk
[Tony_Scamurra] Tony Scamurra mailto:Tony&desktoppaging.com
[Troy_Gau] Troy Gau mailto:troy&zyxel.com
[Weldon_J_Showalter] Weldon J. Showalter mailto:Gamma&mintaka.dca.mil
[Zan_Oliphant] Zan Oliphant mailto:zan&accessone.com