Port 4353F5 iQuery

F5 iQuery is a BIG-IP peer protocol used by BIG-IP DNS to exchange status and monitoring information with other BIG-IP systems.

inNetwork Services

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

also known as BIG-IP iQuery, GTM iQuery

Technical Details

what runs on :4353

iQuery is F5's proprietary inter-device protocol. BIG-IP DNS typically initiates a persistent TCP connection to peer BIG-IP systems on port 4353 to exchange monitoring and status information; iQuery traffic is normally SSL/TLS-protected. IANA lists both TCP and UDP for the assignment, but operational iQuery is principally associated with TCP. This is separate from ordinary DNS queries on port 53.

Security Information

exposure of :4353

risk score

6/ 10risk

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

network services averages 2.6 across 1,531 ports — this one sits 3.4 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 · udp

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

security overview

This is an appliance-to-appliance control and monitoring channel, not a service intended for general internet access. Restrict it to the specific trusted BIG-IP peers that need it; exposure can reveal internal device and service status, and relying on encryption does not make arbitrary peer access safe.

Record

iana registry entry

port: :4353
service: F5 iQuery
transport: TCPUDP
encryption: tls / encrypted
assignment: iana registered
risk: 6/10risk
category: Network Services
usage: BIG-IP DNS (formerly BIG-IP GTM) uses iQuery to communicate with BIG-IP systems, commonly to monitor virtual-server availability and obtain status information. Engineers typically encounter it between F5 appliances, not as a client-facing service.
lookups: 0rank 993
added: 2026-10-04
updated: 2026-10-04
references: IANA service name registry — port 4353

Something wrong?

This record is maintained by the engineers who use port 4353. 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 2026-10-04.

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 1,531 in network services →

the 8 most looked-up other ports in network services — 1,531 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 :4353F5 iQuery

Technical Details

Security Information

Related Ports

Port 4353F5 iQuery