Port 6784Bidirectional Forwarding Detection (BFD) for LAG

UDP port 6784 carries BFD control packets used to monitor individual links in a Link Aggregation Group.

transport: udp
in transit: cleartext
assignment: official
risk: 2/10
lookups: 0

also known as bfd-lag, BFD on LAG interfaces, BFD for LAG

Technical Details

what runs on :6784

Defined by RFC 7130, BFD for LAG uses UDP destination port 6784 to carry BFD control packets for member-link sessions. Devices run a session per member link so they can detect a failed member and remove it from the bundle promptly; the packets are associated with the member link and are not ordinary application traffic. This differs from the more familiar BFD UDP ports used for other session types (such as 3784 for single-hop BFD and 4784 for multihop BFD).

Security Information

exposure of :6784

risk score

2/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

network services averages 2.6 across 1,748 ports — this one sits 0.6 below.

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

udp

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

security overview

BFD packets are not encrypted by default. A device able to inject traffic on the relevant link may be able to spoof or disrupt session state and cause a member link to be treated as failed; BFD authentication is available, but its use depends on implementation and configuration. This is a link-adjacent network-control protocol, not one that should normally be exposed to the public internet; restrict it to intended links and apply control-plane protections.

Record

iana registry entry

port: :6784
service: Bidirectional Forwarding Detection (BFD) for LAG
transport: UDP
encryption: cleartext
assignment: iana registered
risk: 2/10safe
category: Network Services
usage: Network equipment uses BFD for LAG to detect failures on individual member links of a Link Aggregation Group, rather than treating the bundle as one link. It is generally encountered between directly connected routers or switches with the feature enabled, not as a typical internet-facing host service.
lookups: 0rank 993
added: 2026-10-11
updated: 2026-10-11
references: IANA service name registry — port 6784
RFC 7130

Something wrong?

This record is maintained by the engineers who use port 6784. 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.

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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 :6784Bidirectional Forwarding Detection (BFD) for LAG

Technical Details

Security Information

Related Ports

Port 6784Bidirectional Forwarding Detection (BFD) for LAG