Port 6653OpenFlow

OpenFlow carries control-plane messages between SDN controllers and network switches, usually over TCP.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 8/10
lookups: 0

also known as OpenFlow protocol, 6633

Technical Details

what runs on :6653

OpenFlow is the protocol used between an SDN controller and a switch. The IANA assignment lists both TCP and UDP, but normal OpenFlow deployments use a TCP control connection; UDP is not the usual OpenFlow transport. After connecting, the peers exchange OpenFlow Hello messages to establish a protocol version, then use length-framed messages for capability negotiation, events, statistics, and flow-rule updates. Port 6653 is the standard port; older deployments may use TCP port 6633. OpenFlow can use TLS, but encryption is not automatic and many deployments use plain TCP on a restricted management network.

Security Information

exposure of :6653

risk score

8/ 10risk

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

network services averages 2.6 across 1,735 ports — this one sits 5.4 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

An exposed OpenFlow control channel can reveal network state and, depending on the switch and connection configuration, allow an attacker to alter forwarding behavior or disrupt traffic. The protocol does not make encryption or strong peer authentication automatic; use TLS with appropriate certificate checks where supported, and restrict access to trusted controller and switch addresses. Do not expose the port to the public internet.

Record

iana registry entry

port: :6653
service: OpenFlow
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 8/10risk
category: Network Services
usage: An SDN switch uses this control channel to connect to a controller, which can inspect switch capabilities and install or modify forwarding rules. Engineers encounter it on controller and switch management networks; it is not normally intended to be reachable from the public internet.
lookups: 0rank 993
added: 2026-10-11
updated: 2026-10-11
references: IANA service name registry — port 6653

Something wrong?

This record is maintained by the engineers who use port 6653. 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 2026-10-11.

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

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risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :6653OpenFlow

Technical Details

Security Information

Related Ports

Port 6653OpenFlow