Port 19998Secure IEC 60870-5-104

Secure IEC 60870-5-104 telecontrol over TLS, typically used for SCADA links between control centers and substations.

transport: tcp
in transit: encrypted
assignment: official
risk: 8/10
lookups: 0

also known as iec-104-sec, IEC 60870-5-104 over TLS, IEC 62351-3

Technical Details

what runs on :19998

The expected service is IEC 60870-5-104 carried over TLS, as described by the IEC 62351 security framework. A TLS handshake occurs before IEC-104 application data; within the protected connection, IEC-104 uses APDUs with a start byte (0x68), length and control fields, and may carry ASDUs. TCP/2404 is the commonly used port for unprotected IEC-104; TCP/19998 is the IANA-assigned secure port. TLS versions, certificates, and authentication behavior depend on the implementation and its configuration.

Security Information

exposure of :19998

risk score

8/ 10risk

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

security averages 2.9 across 439 ports — this one sits 5.1 above.

in transit

encrypted

payloads are protected on the wire

assignment

official

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

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

IEC-104 can convey telecontrol commands as well as status and measurements, so an exposed endpoint may provide access to sensitive operational functions. TLS protects the connection in the expected secure deployment, but does not make an internet-facing control service safe: restrict access to trusted OT networks and enforce appropriate certificate validation, authorization, and network controls. No particular vulnerability is implied by the port assignment.

Record

iana registry entry

port: :19998
service: Secure IEC 60870-5-104
transport: TCP
encryption: tls / encrypted
assignment: iana registered
risk: 8/10risk
category: Security Network Services
usage: TCP/19998 is assigned for the secure form of IEC 60870-5-104, a telecontrol protocol used in SCADA and power-system communications. An engineer would expect a configured IEC-104 implementation using TLS; ordinary IEC-104 commonly uses TCP/2404, and this port has not appeared open in the cited internet-wide scan data.
lookups: 0rank 993
added: 2026-10-18
updated: 2026-10-18
references: IANA service name registry — port 19998

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This record is maintained by the engineers who use port 19998. 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 2026-10-18.

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Related Ports

all 439 in security →

the 8 most looked-up other ports in security — 439 ports carry that label.

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:3128	Squid Proxy HTTP	TCP	Web Services	caution	45.8k
:8080	HTTP Alternate	TCP	Web Services	caution	44.9k
:7000	Vuze HTTPS Tracker	TCPtls	Security	caution	28.9k

risk mix of the 8 listed

caution100%

2 of 8 encrypted

Port :19998Secure IEC 60870-5-104

Technical Details

Security Information

Related Ports

Port 19998Secure IEC 60870-5-104