Port 4555RSIP

IANA-assigned TCP and UDP port for the RSIP service, rarely observed open on the public internet.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 5/10
lookups: 0

Technical Details

what runs on :4555

An RSIP server uses TCP and/or UDP port 4555 for client control traffic. Clients establish an RSIP session, negotiate capabilities, and request, renew, or release public address and port resources; the gateway then maintains the corresponding forwarding state. RSIP messages use a structured control protocol, while application traffic uses the allocated public ports rather than a fixed companion data port. The protocol itself does not provide general-purpose application proxying.

Security Information

exposure of :4555

risk score

5/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

network services averages 2.7 across 1,395 ports — this one sits 2.3 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

Port 4555 should normally be reachable only by trusted RSIP clients on the private side of the gateway. RSIP control traffic is not encrypted by default, and an exposed server could allow unauthorized allocation or manipulation of NAT resources, potentially bypassing network policy or consuming address and port capacity. Use access controls and, where required, protocol authentication or IPsec; do not publish it directly to the Internet.

Record

iana registry entry

port: :4555
service: RSIP
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 5/10caution
category: Network Services
usage: RSIP lets hosts in a private realm request public IP addresses and transport ports from an RSIP gateway. It is an uncommon NAT-traversal deployment, typically found between trusted internal clients and a gateway rather than exposed to the public Internet.
lookups: 0rank 993
added: 2026-09-09
updated: 2026-09-22
references: IANA service name registry — port 4555
RFC 3103

Something wrong?

This record is maintained by the engineers who use port 4555. 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
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

all 1,395 in network services →

the 8 most looked-up other ports in network services — 1,395 ports carry that label.

port	service	proto	category	risk	views
:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:6543	Jetnet	UDP	Network Services	caution	65.3k
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3233	WhiskerControl Protocol	TCPUDP	Network Services	caution	61.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Tatsoft Default HTTP Proxy	TCP	Web Services	caution	46.8k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :4555RSIP

Technical Details

Security Information

Related Ports

Port 4555RSIP