Port 21000IRTrans Control

Control traffic for IRTrans infrared remote-control devices.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 6/10
lookups: 0

Technical Details

what runs on :21000

IRTrans devices normally expose their control protocol on TCP port 21000 and may use UDP 21000 for discovery or datagram-based device functions. The service is not HTTP or a general-purpose remote shell: clients exchange IRTrans-specific command and response messages, typically using the vendor's ASCII/control protocol to select a device, transmit a learned code, or request IR reception. The exact command framing depends on the IRTrans software and firmware mode, but deployments generally use the default 21000 port unless configured otherwise.

Security Information

exposure of :21000

risk score

6/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

iot averages 3.4 across 149 ports — this one sits 2.6 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

IRTrans control traffic is normally unencrypted and should not be exposed directly to the public internet. An accessible gateway may allow an unauthenticated or weakly protected client to operate connected infrared equipment, send arbitrary learned commands, or potentially interfere with automation; restrict access to trusted management networks or a VPN and filter both TCP and UDP.

Record

iana registry entry

port: :21000
service: IRTrans Control
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 6/10risk
category: IoT
usage: This port is used by IRTrans Ethernet and LAN infrared gateways, often deployed to control televisions, audiovisual equipment, air conditioners, and other IR-controlled devices. Automation software connects to the gateway to transmit learned IR codes or receive IR input; UDP may also be used for device discovery or related control functions.
lookups: 0rank 993
added: 2026-08-21
updated: 2026-09-22
references: IANA service name registry — port 21000

Something wrong?

This record is maintained by the engineers who use port 21000. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-09-22.

01edit any field on a page of its own
02a model checks it for accuracy and spam
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edit this record →back to the registry

Related Ports

all 149 in iot →

the 8 most looked-up other ports in iot — 149 ports carry that label.

port	service	proto	category	risk	views
:6543	Jetnet	UDP	Network Services	caution	65.3k
:3233	WhiskerControl Protocol	TCPUDP	Network Services	caution	61.9k
:9600	Omron FINS Communication	UDP	Network Services	caution	33.2k
:4840	OPC UA TCP	TCPUDP	Network Services	caution	26.6k
:5678	Mikrotik MNDP	UDP	Network Services	caution	24.7k
:4843	OPC UA over TLS/SSL	TCPUDPtls	Security	caution	24.6k
:5001	Slingbox	TCP	Streaming	caution	22.4k
:15000	Hypack Data Acquisition	TCP	Network Services	caution	21.4k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :21000IRTrans Control

Technical Details

Security Information

Related Ports

Port 21000IRTrans Control