Port 4784BFD Multihop Control

BFD Multihop Control detects forwarding-path failures between nonadjacent network devices.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 4/10
lookups: 0

also known as bfd-multi-ctl, Bidirectional Forwarding Detection multihop

Technical Details

what runs on :4784

BFD provides rapid, lightweight failure detection by exchanging periodic control packets between session endpoints and tracking negotiated transmit and receive intervals, session state, and a detection multiplier. Multihop BFD uses UDP destination port 4784 and supports paths spanning one or more routed hops; it is not normally a TCP protocol, despite the TCP assignment also present in the registry. Related BFD assignments include UDP 3784 for single-hop control and UDP 3785 for BFD Echo. BFD packets are not encrypted by default, and authentication is optional.

Security Information

exposure of :4784

risk score

4/ 10caution

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

security averages 3.4 across 281 ports — this one sits 0.6 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

BFD is a network-control protocol rather than an application service and should normally be restricted to explicitly configured peers with network ACLs. An attacker able to inject or disrupt BFD packets may flap sessions, trigger routing or forwarding failover, or consume device resources; the cleartext protocol also provides no confidentiality by default. It should not be exposed broadly to the public internet.

Record

iana registry entry

port: :4784
service: BFD Multihop Control
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 4/10caution
category: Security Network Services
usage: This port carries Bidirectional Forwarding Detection (BFD) control sessions across multihop paths, typically between routers or other network devices. IANA lists both TCP and UDP for the assignment, but standardized BFD multihop deployments normally use UDP port 4784.
lookups: 0rank 994
added: 2026-09-06
updated: 2026-09-06
references: IANA service name registry — port 4784

Something wrong?

This record is maintained by the engineers who use port 4784. 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 2026-09-06.

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 281 in security →

the 8 most looked-up other ports in security — 281 ports carry that label.

port	service	proto	category	risk	views
:8881	Atlasz Secure Server	TCP	Web Services	caution	67.6k
:443	HTTPS	TCPtls	Web Services	caution	65.9k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Squid Proxy HTTP	TCP	Web Services	caution	45.8k
:8080	HTTP Alternate	TCPtls	Web Services	caution	44.9k
:7000	Vuze HTTPS Tracker	TCPtls	Security	caution	28.9k

risk mix of the 8 listed

caution100%

3 of 8 encrypted

Port :4784BFD Multihop Control

Technical Details

Security Information

Related Ports

Port 4784BFD Multihop Control