UDP 3784
Synopsis
- UDP port 3784 is the IANA-assigned port for BFD (Bidirectional Forwarding Detection) control packets, specifically for single-hop BFD sessions.
- Network OSes that use UDP/3784 for BFD include Cisco IOS/IOS XE/IOS XR, Juniper Junos, Arista EOS, Nokia SR OS, and MikroTik RouterOS.
- It’s widely deployed to provide fast failure detection for routing protocols such as OSPF, IS-IS, and BGP on routers and switches.
- Open-source implementations using this port include FRRouting’s bfdd, BIRD’s BFD support, and OpenBFDD.
- Note: multi-hop BFD uses UDP port 4784, not 3784.
Observed activity
Last 30 days
Detailed chart