Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2024-04-12
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
gacp 190 udp Gateway Access Control Protocol [C_Philip_Wood] [C_Philip_Wood]
prospero 191 tcp Prospero Directory Service [B_Clifford_Neuman] [B_Clifford_Neuman]
prospero 191 udp Prospero Directory Service [B_Clifford_Neuman] [B_Clifford_Neuman]
osu-nms 192 tcp OSU Network Monitoring System [Doug_Karl] [Doug_Karl]
osu-nms 192 udp OSU Network Monitoring System [Doug_Karl] [Doug_Karl]
srmp 193 tcp Spider Remote Monitoring Protocol [Ted_J_Socolofsky] [Ted_J_Socolofsky]
srmp 193 udp Spider Remote Monitoring Protocol [Ted_J_Socolofsky] [Ted_J_Socolofsky]
irc 194 tcp Internet Relay Chat Protocol [Jarkko_Oikarinen] [Jarkko_Oikarinen]
irc 194 udp Internet Relay Chat Protocol [Jarkko_Oikarinen] [Jarkko_Oikarinen]
dn6-nlm-aud 195 tcp DNSIX Network Level Module Audit
dn6-nlm-aud 195 udp DNSIX Network Level Module Audit
dn6-smm-red 196 tcp DNSIX Session Mgt Module Audit Redir [Lawrence_Lebahn] [Lawrence_Lebahn]
dn6-smm-red 196 udp DNSIX Session Mgt Module Audit Redir [Lawrence_Lebahn] [Lawrence_Lebahn]
dls 197 tcp Directory Location Service
dls 197 udp Directory Location Service
dls-mon 198 tcp Directory Location Service Monitor [Scott_Bellew] [Scott_Bellew]
dls-mon 198 udp Directory Location Service Monitor [Scott_Bellew] [Scott_Bellew]
smux 199 tcp SMUX [Marshall_Rose] [Marshall_Rose]
smux 199 udp SMUX [Marshall_Rose] [Marshall_Rose]
src 200 tcp IBM System Resource Controller [Gerald_McBrearty] [Gerald_McBrearty]
src 200 udp IBM System Resource Controller [Gerald_McBrearty] [Gerald_McBrearty]
at-rtmp 201 tcp AppleTalk Routing Maintenance
at-rtmp 201 udp AppleTalk Routing Maintenance
at-nbp 202 tcp AppleTalk Name Binding
at-nbp 202 udp AppleTalk Name Binding
at-3 203 tcp AppleTalk Unused
at-3 203 udp AppleTalk Unused
at-echo 204 tcp AppleTalk Echo
at-echo 204 udp AppleTalk Echo
at-5 205 tcp AppleTalk Unused
at-5 205 udp AppleTalk Unused
at-zis 206 tcp AppleTalk Zone Information
at-zis 206 udp AppleTalk Zone Information
at-7 207 tcp AppleTalk Unused
at-7 207 udp AppleTalk Unused
at-8 208 tcp AppleTalk Unused [Rob_Chandhok] [Rob_Chandhok]
at-8 208 udp AppleTalk Unused [Rob_Chandhok] [Rob_Chandhok]
qmtp 209 tcp The Quick Mail Transfer Protocol [D_J_Bernstein] [D_J_Bernstein] 2018-04-05
qmtp 209 udp The Quick Mail Transfer Protocol [D_J_Bernstein] [D_J_Bernstein] 2018-04-05
z39-50 210 tcp 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 tcp 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.
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 tcp 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 tcp 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.
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 tcp ATEXSSTR [Jim_Taylor] [Jim_Taylor]
anet 212 udp ATEXSSTR [Jim_Taylor] [Jim_Taylor]
ipx 213 tcp IPX [Don_Provan] [Don_Provan]
ipx 213 udp IPX [Don_Provan] [Don_Provan]
vmpwscs 214 tcp VM PWSCS [Dan_Shia] [Dan_Shia]
vmpwscs 214 udp VM PWSCS [Dan_Shia] [Dan_Shia]
softpc 215 tcp Insignia Solutions [Martyn_Thomas] [Martyn_Thomas]
softpc 215 udp Insignia Solutions [Martyn_Thomas] [Martyn_Thomas]
CAIlic 216 tcp Computer Associates Int'l License Server [Chuck_Spitz] [Chuck_Spitz]
CAIlic 216 udp Computer Associates Int'l License Server [Chuck_Spitz] [Chuck_Spitz]
dbase 217 tcp dBASE Unix [Don_Gibson] [Don_Gibson]
dbase 217 udp dBASE Unix [Don_Gibson] [Don_Gibson]
mpp 218 tcp Netix Message Posting Protocol [Shannon_Yeh] [Shannon_Yeh]
mpp 218 udp Netix Message Posting Protocol [Shannon_Yeh] [Shannon_Yeh]
uarps 219 tcp Unisys ARPs [Ashok_Marwaha] [Ashok_Marwaha]
uarps 219 udp Unisys ARPs [Ashok_Marwaha] [Ashok_Marwaha]
imap3 220 tcp Interactive Mail Access Protocol v3 [James_Rice] [James_Rice]
imap3 220 udp Interactive Mail Access Protocol v3 [James_Rice] [James_Rice]
fln-spx 221 tcp Berkeley rlogind with SPX auth
fln-spx 221 udp Berkeley rlogind with SPX auth
rsh-spx 222 tcp Berkeley rshd with SPX auth
rsh-spx 222 udp Berkeley rshd with SPX auth
cdc 223 tcp Certificate Distribution Center [Kannan_Alagappan] [Kannan_Alagappan]
cdc 223 udp Certificate Distribution Center [Kannan_Alagappan] [Kannan_Alagappan]
masqdialer 224 tcp masqdialer [Charles_Wright] [Charles_Wright] Possible Conflict of Port 222 with "Masqdialer"
masqdialer 224 udp masqdialer [Charles_Wright] [Charles_Wright] Possible Conflict of Port 222 with "Masqdialer"
225-241 Reserved [Jon_Postel] [Jon_Postel]
direct 242 tcp Direct [Herb_Sutter] [Paul_Horton]
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 [Jon_Postel] [Jon_Postel]
rap 256 tcp RAP [J_S_Greenfield] [J_S_Greenfield]
rap 256 udp RAP [J_S_Greenfield] [J_S_Greenfield]
set 257 tcp Secure Electronic Transaction [Donald_Eastlake] [Donald_Eastlake]
set 257 udp Secure Electronic Transaction [Donald_Eastlake] [Donald_Eastlake]
258 Unassigned 2006-09-13
esro-gen 259 tcp Efficient Short Remote Operations [Mohsen_Banan] [Mohsen_Banan]
esro-gen 259 udp Efficient Short Remote Operations [Mohsen_Banan] [Mohsen_Banan]
openport 260 tcp Openport [John_Marland] [John_Marland]
openport 260 udp Openport [John_Marland] [John_Marland]
nsiiops 261 tcp IIOP Name Service over TLS/SSL [Jeff_Stewart] [Jeff_Stewart]

Contact Information

ID Name Contact URI Last Updated
[Ashok_Marwaha] Ashok Marwaha
[B_Clifford_Neuman] B. Clifford Neuman mailto:bcn&isi.edu 2022-02-18
[Bill_Harrell] Bill Harrell
[C_Philip_Wood] C. Philip Wood mailto:cpw&lanl.gov
[Charles_Wright] Charles Wright mailto:cpwright&villagenet.com
[Chuck_Spitz] Chuck Spitz mailto:spich04&cai.com
[D_J_Bernstein] D. J. Bernstein mailto:ports&box.cr.yp.to 2018-04-05
[Dan_Shia] Dan Shia mailto:dset!shia&uunet.uu.net
[Dave_Clark] Dave Clark mailto:ddc&lcs.mit.edu
[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_Eastlake] Donald Eastlake mailto:d3e3e3&gmail.com
[Doug_Karl] Doug Karl mailto:KARL-D&osu-20.ircc.ohio-state.edu
[Gerald_McBrearty] Gerald McBrearty
[Herb_Sutter] Herb Sutter mailto:HerbS&cntc.com
[J_S_Greenfield] J. S. Greenfield mailto:greeny&raleigh.ibm.com
[James_Rice] James Rice mailto:RICE&sumex-aim.stanford.edu
[Jarkko_Oikarinen] Jarkko Oikarinen mailto:jto&tolsun.oulu.fi
[Jeff_Stewart] Jeff Stewart mailto:jstewart&netscape.com
[Jim_Taylor] Jim Taylor mailto:taylor&heart.epps.kodak.com
[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
[Jon_Postel] Jon Postel mailto:postel&isi.edu
[Kannan_Alagappan] Kannan Alagappan mailto:kannan&sejour.enet.dec.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:mrose&dbc.mtview.ca.us
[Martyn_Thomas] Martyn Thomas
[Mohsen_Banan] Mohsen Banan mailto:mohsen&rostam.neda.com
[Paul_Horton] Paul Horton mailto:paul.horton&dxstro.com 2016-05-18
[Rob_Chandhok] Rob Chandhok mailto:chandhok&gnome.cs.cmu.edu
[Scott_Bellew] Scott Bellew mailto:smb&cs.purdue.edu
[Shannon_Yeh] Shannon Yeh mailto:yeh&netix.com
[Ted_J_Socolofsky] Ted J. Socolofsky mailto:Teds&spider.co.uk
[Weldon_J_Showalter] Weldon J. Showalter mailto:Gamma&mintaka.dca.mil