knownports / Ports 300–399 / Port 300

Port300

  • tacacssTLS Secure Login Host Protocol (TACACSS)

IANA has registered port 300 to tacacss on TCP; UDP 300 is held as reserved. The entry cites RFC 9887. It is the TLS counterpart of tacacs on port 49.

  1. 284corerjd
  2. 1 free
  3. 286fxp
  4. 287k-block
  5. 12 free
  6. 300tacacss
  7. 7 free
  8. 308novastorbakcup
  9. 309entrusttime
  10. 310bhmds
TCP assignedUDP assignedreservedno entryAll 74 assigned numbers in ports 300–399

Registry entries

ServiceProtocolsRegisteredModifiedRFCsOther specs
tacacssTCPJul 15, 2025—RFC 9887—

Cited RFCs

RFCTitlePublishedStatusLater changes
RFC 9887Terminal Access Controller Access-Control System Plus (TACACS+) over TLS 1.3December 2025Proposed Standard—

Where it sits in the registry

Port 300 is one of 74 numbers with an assignment in ports 300–399 (74.0% of the range). Two other numbers in the range are assigned on exactly the same transport, TCP. Its first recorded registration, July 15, 2025, is the most recent of the 5 dates recorded in the range.

Status on each protocol

ProtocolOn port 300Other numbers with the same statusNearest with the same status
TCPassigned to tacacss5,887308 novastorbakcup
UDPreserved566323 rpki-rtr
SCTPno entry5,999308 novastorbakcup
DCCPno entry6,080308 novastorbakcup

540 other assigned numbers in the registry have exactly this combination across all four protocols.

The nearest assigned numbers

PortServiceLabelProtocolsRegisteredDistance
284corerjd—TCPUDP—16
286fxpFXP CommunicationTCPUDP—14
287k-block—TCPUDP—13
308novastorbakcupNovastor BackupTCPUDP—8
309entrusttime—TCPUDP—9
310bhmds—TCPUDP—10

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