Port 654 carries AODV—Ad hoc On-Demand Distance Vector routing. This is the protocol that lets devices build networks when there's no infrastructure to rely on.
When cell towers are destroyed in a disaster. When military units operate beyond signal range. When rescue drones need to coordinate in the sky above a flood zone. AODV is how those devices find paths to each other, on demand, without any central authority telling them how.1
All AODV messages—route requests, route replies, route errors—flow through port 654 using UDP.2
How AODV Works
In a traditional network, routers maintain tables of where to send packets. They know the map. But in a mobile ad hoc network (MANET), there is no map. Devices are moving. The topology changes constantly. Infrastructure doesn't exist.
AODV solves this by being on-demand. Devices don't maintain routes to everywhere—they discover routes only when needed.3
When a device needs to send data to another device, it broadcasts a Route Request (RREQ) to port 654. That message floods through the network, device to device, until it reaches the destination. The destination then sends back a Route Reply (RREP), also to port 654, which travels back along the path that was discovered. Now both devices know the route.4
If a link breaks—if a device moves out of range or fails—a Route Error (RERR) message is sent to port 654, notifying upstream devices that the path is no longer valid.5
Every route entry includes a destination sequence number, created by the destination itself. This simple mechanism prevents routing loops—the classic problem where packets circle endlessly through the network.6
The Problem AODV Solved
In the late 1990s, researchers were trying to build networks for scenarios where infrastructure couldn't be assumed. Military operations. Disaster zones. Search and rescue.
Proactive routing protocols—where every device maintains a full map of the network—didn't scale. In a network of constantly moving nodes, the overhead of maintaining complete routing tables was crushing.
Charles Perkins at Sun Microsystems and Elizabeth Royer at UC Santa Barbara created AODV in 1999 to solve this.7 The insight was simple: don't maintain routes you're not using. Discover them when needed. Keep them while they're valid. Discard them when they break.
AODV was published as RFC 3561 in 2003.8
Where AODV Is Used Today
Disaster response: When floods or earthquakes destroy cellular infrastructure, rescue drones use AODV to form instant networks in the air, providing coverage and coordination for rescue teams on the ground.9
Military operations: Mobile ad hoc networks are critical in battlefield scenarios where infrastructure is unavailable or compromised. AODV allows units to maintain communication without relying on fixed infrastructure.10
UAV swarms: Multiple drones coordinating for surveillance, delivery, or monitoring use AODV-based protocols to discover and maintain routes between aircraft as they move.11
Mesh networks: WiFi mesh networks, including IEEE 802.11s, use hybrid protocols based on AODV principles—radio-metric AODV (RM-AODV) and Hybrid Wireless Mesh Protocol (HWMP).12
Security Considerations
AODV was designed for mobility and efficiency, not security. The protocol has no built-in authentication or encryption.
An attacker could:
- Broadcast false route information to redirect traffic
- Create routing loops by manipulating sequence numbers
- Perform denial-of-service attacks by flooding route requests
- Impersonate nodes to intercept communications
Secure AODV (SAODV) extensions exist that add cryptographic authentication to route messages, but they introduce overhead and are not universally deployed.13
If you're deploying AODV in a production environment, encrypt application-layer traffic and consider authentication mechanisms for route messages.
Related Protocols and Ports
AODV is part of a family of MANET routing protocols:
- DSR (Dynamic Source Routing): Another on-demand protocol, but uses source routing where the entire path is included in packet headers
- OLSR (Optimized Link State Routing): A proactive protocol that maintains routes to all destinations
- HWMP (Hybrid Wireless Mesh Protocol): Used in IEEE 802.11s mesh networks, combines AODV principles with proactive routing
All AODV traffic uses UDP on port 654. There is no TCP variant—routing messages must be lightweight and don't require the overhead of connection establishment.
How to Check What's Using Port 654
On Linux or macOS:
On Windows:
If you see traffic on port 654, you're likely looking at AODV routing messages from a mobile ad hoc network or mesh network implementation.
Frequently Asked Questions About Port 654
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