knownports / Ports 800–1023 / Port 853

Port853

  • domain-sDNS query-response protocol run over TLS

IANA has registered port 853 to domain-s on TCP and UDP. The entry cites RFC 7858, RFC 8094 and RFC 9250. It is the TLS counterpart of domain on port 53.

  1. 830netconf-ssh
  2. 16 free
  3. 847dhcp-failover2
  4. 848gdoi
  5. 4 free
  6. 853domain-s
  7. 854dlep
  8. 5 free
  9. 860iscsi
  10. 861owamp-control
TCP assignedUDP assignedreservedno entryAll 44 assigned numbers in ports 800–1023

Registry entries

ServiceProtocolsRegisteredModifiedRFCsOther specs
domain-sTCPUDPOct 8, 2015Apr 11, 2022RFC 7858, RFC 8094, RFC 9250—

Cited RFCs

RFCTitlePublishedStatusLater changes
RFC 7858Specification for DNS over Transport Layer Security (TLS)May 2016Proposed Standardupdated by RFC 8310
RFC 8094DNS over Datagram Transport Layer Security (DTLS)February 2017Experimental—
RFC 9250DNS over Dedicated QUIC ConnectionsMay 2022Proposed Standard—

Where it sits in the registry

Port 853 is one of 44 numbers with an assignment in ports 800–1023 (19.6% of the range). 36 other numbers in the range are assigned on exactly the same transports, TCP and UDP, the usual pattern for older entries. Of the 7 numbers in the range with a recorded registration date, one was registered before it (October 8, 2015) and five after. IANA last modified the entry on April 11, 2022, seven years after the first recorded registration. No other number in the registry shares that modification date.

Status on each protocol

ProtocolOn port 853Other numbers with the same statusNearest with the same status
TCPassigned to domain-s5,887854 dlep
UDPassigned to domain-s5,500854 dlep
SCTPno entry5,999854 dlep
DCCPno entry6,080854 dlep

5,273 other assigned numbers in the registry have exactly this combination across all four protocols.

The nearest assigned numbers

PortServiceLabelProtocolsRegisteredDistance
830netconf-sshNETCONF over SSHTCPUDP—23
847dhcp-failover2dhcp-failover 2TCPUDP—6
848gdoi—TCPUDP—5
854dlepDynamic Link Exchange Protocol (DLEP)TCPUDPApr 3, 20171
860iscsi—TCPUDP—7
861owamp-control—TCP—8
861owamp-test—UDP—8

Listed in Ports that cite an RFC · Plain and TLS port pairs