Internet Assigned Numbers Authority

Service Name and Transport Protocol Port Number Registry

Last Updated
2024-03-18
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
smtp 25 tcp Simple Mail Transfer [IESG] [IETF_Chair] 2017-06-05 [RFC5321]
smtp 25 udp Simple Mail Transfer [IESG] [IETF_Chair] 2017-06-05 [RFC5321]
http 80 tcp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] Defined TXT keys: u=<username> p=<password> path=<path to document>
http 80 udp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] Defined TXT keys: u=<username> p=<password> path=<path to document>
www 80 tcp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] This is a duplicate of the "http" service and should not be used for discovery purposes.
www 80 udp World Wide Web HTTP [IESG] [IETF_Chair] 2021-10-01 [RFC9110] This is a duplicate of the "http" service and should not be used for discovery purposes.
nntp 119 tcp Network News Transfer Protocol [IESG] [IETF_Chair] 2018-07-06 [RFC3977]
nntp 119 udp Network News Transfer Protocol [IESG] [IETF_Chair] 2018-07-06 [RFC3977]
imap 143 tcp Internet Message Access Protocol [IESG] [IETF_Chair] 2021-02-22 [RFC3501][RFC9051]
pt-tls 271 tcp IETF Network Endpoint Assessment (NEA) Posture Transport Protocol over TLS (PT-TLS) [IESG] [IETF_Chair] 2012-07-31 [RFC6876]
rpki-rtr 323 tcp Resource PKI to Router Protocol [IESG] [IETF_Chair] [RFC6810]
rpki-rtr-tls 324 tcp Resource PKI to Router Protocol over TLS [IESG] [IETF_Chair] [RFC6810]
nnsp 433 tcp NNTP for transit servers (NNSP) [IESG] [IETF_Chair] 2018-07-06 [RFC3977]
nnsp 433 udp NNTP for transit servers (NNSP) [IESG] [IETF_Chair] 2018-07-06 [RFC3977]
https 443 tcp http protocol over TLS/SSL [IESG] [IETF_Chair] 2021-10-01 [RFC9110]
https 443 udp http protocol over TLS/SSL [IESG] [IETF_Chair] 2021-10-01 [RFC9110]
submissions 465 tcp Message Submission over TLS protocol [IESG] [IETF_Chair] 2017-12-12 [RFC8314]
dhcpv6-client 546 udp DHCPv6 Client [IESG] [IETF_Chair] 2018-05-21 [RFC8415]
dhcpv6-server 547 tcp DHCPv6 Server [IESG] [IETF_Chair] 2018-05-21 [RFC5460]
dhcpv6-server 547 udp DHCPv6 Server [IESG] [IETF_Chair] 2018-05-21 [RFC8415]
nntps 563 tcp nntp protocol over TLS/SSL (was snntp) [IESG] [IETF_Chair] 2018-07-06 [RFC4642]
nntps 563 udp nntp protocol over TLS/SSL (was snntp) [IESG] [IETF_Chair] 2018-07-06 [RFC4642]
ipp 631 tcp IPP (Internet Printing Protocol) [IESG] [IETF_Chair] 2018-07-06 [RFC8011] Defined TXT keys: See BonjourPrinting.pdf.
ipp 631 udp IPP (Internet Printing Protocol) [IESG] [IETF_Chair] 2018-07-06 [RFC8011] Defined TXT keys: See BonjourPrinting.pdf.
ipps 631 tcp Internet Printing Protocol over HTTPS [IESG] [IETF_Chair] 2018-07-06 [RFC8011]
dhcp-failover 647 tcp DHCP Failover [IESG] [IETF_Chair] 2018-05-21 [RFC8156]
domain-s 853 tcp DNS query-response protocol run over TLS [IESG] [IETF_Chair] 2015-10-08 2022-04-11 [RFC7858]
domain-s 853 udp DNS query-response protocol run over DTLS or QUIC [IESG] [IETF_Chair] 2015-10-08 2022-04-01 [RFC7858][RFC8094][RFC9250]
dlep 854 tcp Dynamic Link Exchange Protocol (DLEP) [IESG] [IETF_Chair] 2017-04-03 [RFC8175]
dlep 854 udp Dynamic Link Exchange Protocol (DLEP) [IESG] [IETF_Chair] 2017-04-03 [RFC8175]
iscsi 860 tcp iSCSI [IESG] [IETF_Chair] 2013-08-27 [RFC7143]
iscsi 860 udp iSCSI [IESG] [IETF_Chair] 2013-08-27 [RFC7143]
owamp-control 861 tcp OWAMP-Control [IESG] [IETF_Chair] [RFC4656]
owamp-test 861 udp OWAMP-Test [IESG] [IETF_Chair] 2018-12-21 [RFC8545]
twamp-control 862 tcp TWAMP-Control [IESG] [IETF_Chair] [RFC5357]
twamp-test 862 udp TWAMP-Test Receiver Port [IESG] [IETF_Chair] 2018-12-21 [RFC8545]
imaps 993 tcp IMAP over TLS protocol [IESG] [IETF_Chair] 2021-02-22 [RFC3501][RFC8314][RFC9051]
pop3s 995 tcp POP3 over TLS protocol [IESG] [IETF_Chair] 2017-12-12 [RFC8314]
webpush 1001 tcp HTTP Web Push [IESG] [IETF_Chair] 2016-11-01 [RFC8030]
exp1 1021 tcp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 udp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 sctp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp1 1021 dccp RFC3692-style Experiment 1 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 tcp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 udp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 sctp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
exp2 1022 dccp RFC3692-style Experiment 2 [IESG] [IETF_Chair] [1][RFC4727][RFC6335]
6a44 1027 udp IPv6 Behind NAT44 CPEs [IESG] [IETF_Chair] 2012-08-02 [RFC6751]
radsec 2083 tcp Secure Radius Service [IESG] [IETF_Chair] 2005-05 [RFC6614] The TCP port 2083 was already previously assigned by IANA for "RadSec", an early implementation of RADIUS/TLS, prior to issuance of this RFC. This early implementation can be configured to be compatible to RADIUS/TLS as specified by the IETF. See [RFC6614], Appendix A for details.
radsec 2083 udp Secure Radius Service [IESG] [IETF_Chair] 2005-05 2014-07-14 [RFC7360] The UDP port 2083 was already previously assigned by IANA for "RadSec", an early implementation of RADIUS/TLS, prior to issuance of this RFC.
amt 2268 tcp AMT [IESG] [IETF_Chair] 2004-12 2014-12-17 [RFC7450]
amt 2268 udp AMT [IESG] [IETF_Chair] 2004-12 2014-12-17 [RFC7450]
iscsi-target 3260 tcp iSCSI port [IESG] [IETF_Chair] 2013-08-27 [RFC7143]
iscsi-target 3260 udp iSCSI port [IESG] [IETF_Chair] 2013-08-27 [RFC7143]
stun 3478 tcp Session Traversal Utilities for NAT (STUN) port [IESG] [IETF_Chair] 2019-03-28 [RFC8489]
stun 3478 udp Session Traversal Utilities for NAT (STUN) port [IESG] [IETF_Chair] 2019-03-28 [RFC8489]
netconf-ch-ssh 4334 tcp NETCONF Call Home (SSH) [IESG] [IETF_Chair] 2016-01-12 [RFC8071]
netconf-ch-tls 4335 tcp NETCONF Call Home (TLS) [IESG] [IETF_Chair] 2016-01-12 [RFC8071]
restconf-ch-tls 4336 tcp RESTCONF Call Home (TLS) [IESG] [IETF_Chair] 2016-01-12 [RFC8071]
lisp-data 4341 udp LISP Data Packets [IESG] [IETF_Chair] 2007-11-12 2021-02-17 [RFC9300]
lisp-control 4342 udp LISP Control Packets [IETF] [IESG] 2007-05 2021-02-25 [RFC9301]
ntske 4460 tcp Network Time Security Key Establishment [IESG] [IETF_Chair] 2020-04-07 [RFC8915]
dtn-bundle 4556 tcp DTN Bundle TCP CL Protocol [IESG] [IETF_Chair] 2021-02-22 [RFC9174]
rid 4590 tcp RID over HTTP/TLS [IESG] [IETF_Chair] [RFC6546]
dots-signal 4646 tcp Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. [IESG] [IETF_Chair] 2020-01-16 2021-06-14 [RFC8973][RFC9132]
dots-signal 4646 udp Distributed Denial-of-Service Open Threat Signaling (DOTS) Signal Channel Protocol. The service name is used to construct the SRV service names "_dots-signal._udp" and "_dots-signal._tcp" for discovering DOTS servers used to establish DOTS signal channel. [IESG] [IETF_Chair] 2020-01-16 2021-06-14 [RFC8973][RFC9132]
gre-in-udp 4754 udp GRE-in-UDP Encapsulation [IESG] [IETF_Chair] 2016-10-05 [RFC8086]
gre-udp-dtls 4755 udp GRE-in-UDP Encapsulation with DTLS [IESG] [IETF_Chair] 2016-10-05 [RFC8086]
pkix-cmc 5318 tcp PKIX Certificate Management using CMS (CMC) [IESG] [IETF_Chair] [RFC6402]
stuns 5349 tcp Session Traversal Utilities for NAT (STUN) port [IESG] [IETF_Chair] 2019-03-28 [RFC8489]
stuns 5349 udp STUN over DTLS [IESG] [IETF_Chair] 2014-07-03 [RFC7350] This service name was initially created by [RFC5389].
turns 5349 udp TURN over DTLS [IESG] [IETF_Chair] 2019-08-02 [RFC7350] This service name was initially created by [RFC8656].
pcp-multicast 5350 udp Port Control Protocol Multicast [IESG] [IETF_Chair] [RFC6887]
pcp 5351 udp Port Control Protocol [IESG] [IETF_Chair] [RFC6887]
mdns 5353 tcp Multicast DNS [IESG] [IETF_Chair] [RFC6762]
mdns 5353 udp Multicast DNS [IESG] [IETF_Chair] [RFC6762]
coap 5683 tcp Constrained Application Protocol (CoAP) [IESG] [IETF_Chair] 2017-12-22 [RFC8323]
coap 5683 udp Constrained Application Protocol [IESG] [IETF_Chair] 2011-06-13 2013-07-25 [RFC7252]
coaps 5684 tcp Constrained Application Protocol (CoAP) [IESG] [IETF_Chair] 2017-12-22 [RFC7301][RFC8323]
coaps 5684 udp DTLS-secured CoAP [IESG] [IETF_Chair] 2013-07-25 [RFC7252]
diameters 5868 tcp Diameter over TLS/TCP [IESG] [IETF_Chair] [RFC6733]
diameters 5868 sctp Diameter over DTLS/SCTP [IESG] [IETF_Chair] [RFC6733]
geneve 6081 udp Generic Network Virtualization Encapsulation (Geneve) [IESG] [IETF_Chair] 2014-03-27 2020-05-04 [RFC8926]
reload-config 6084 tcp Peer to Peer Infrastructure Configuration [IESG] [IETF_Chair] 2009-01-29 2013-03-26 [RFC6940]
dccp-udp 6511 udp Datagram Congestion Control Protocol Encapsulation for NAT Traversal [IESG] [IETF_Chair] [RFC6773]
netconf-tls 6513 tcp NETCONF over TLS [IESG] [IETF_Chair] 2024-01-24 [RFC7589][RFC-ietf-netconf-over-tls13-04]
mpls-udp 6635 udp Encapsulate MPLS packets in UDP tunnels. [IESG] [IETF_Chair] 2015-02-10 [RFC7510]
mpls-udp-dtls 6636 udp Encapsulate MPLS packets in UDP tunnels with DTLS. [IESG] [IETF_Chair] 2015-02-10 [RFC7510]
babel-dtls 6699 udp Babel Routing Protocol over DTLS [IESG] [IETF_Chair] 2020-09-04 [RFC8968]
bfd-lag 6784 udp Bidirectional Forwarding Detection (BFD) on Link Aggregation Group (LAG) Interfaces [IESG] [BFD_Chairs] 2012-11-08 2014-01-09 [RFC7130]
grasp 7017 tcp GeneRic Autonomic Signaling Protocol [IESG] [IETF_Chair] 2017-04-28 2017-07-20 [RFC8990]
grasp 7017 udp GeneRic Autonomic Signaling Protocol [IESG] [IETF_Chair] 2017-04-28 2017-07-20 [RFC8990]
s-bfd 7784 udp Seamless Bidirectional Forwarding Detection (S-BFD) [IESG] [IETF_Chair] 2014-12-24 2016-07-14 [RFC7881]
mipv6tls 7872 udp TLS-based Mobile IPv6 Security [IESG] [IETF_Chair] 2012-04-12 [RFC6618]
aero 8060 udp Asymmetric Extended Route Optimization (AERO) [IESG] [IETF_Chair] [RFC6706]
hncp-udp-port 8231 udp HNCP [IESG] [IETF_Chair] 2016-01-13 [RFC7788]
hncp-dtls-port 8232 udp HNCP over DTLS [IESG] [IETF_Chair] 2016-01-13 [RFC7788]
pim-port 8471 tcp PIM over Reliable Transport [IESG] [IETF_Chair] 2008-08-21 [RFC6559]
pim-port 8471 sctp PIM over Reliable Transport [IESG] [IETF_Chair] 2008-08-21 [RFC6559]
lsp-self-ping 8503 udp MPLS LSP Self-Ping [IESG] [IETF_Chair] 2015-06-11 2016-02-01 [RFC7746]

Contact Information

ID Name Organization Contact URI Last Updated
[BFD_Chairs] IETF BFD Working Group Chairs mailto:bfd-chairs&tools.ietf.org 2014-01-09
[IESG] IESG mailto:iesg&ietf.org
[IETF] IETF mailto:iesg&ietf.org
[IETF_Chair] IETF Chair IETF mailto:chair&ietf.org