ZRP Zone Routing Protocol Animation

Trace how ZRP uses proactive routes inside a hop-count zone and reactive bordercast discovery beyond it

animation
zrp
manet
hybrid-routing
iarp
ierp
brp
bordercast
networking
A learner-ready Zone Routing Protocol workbench with hop-count zone radius controls, IARP/IERP/BRP route tracing, bordercast evidence, and technical accuracy notes.
Animation Hybrid Routing MANET Intermediate

Trace a ZRP route decision without flooding every node

Zone Routing Protocol keeps proactive routes inside each node's hop-count zone, then uses reactive discovery beyond that zone. Change the radius and scenario to see when IARP is enough and when IERP uses BRP bordercast to reach the edge of the known zone.

2 hopsZone radius around source A
IERP + BRPCurrent routing decision
7 entriesProactive IARP table size
150 ms modelDiscovery delay estimate

ZRP routing controls, route evidence, and learning support

IARP

Maintains routes proactively inside the local routing zone. A destination inside the zone is already in the table.

IERP

Starts reactive route discovery when the destination is beyond the zone radius. It searches only when needed.

BRP

Guides route requests toward peripheral nodes at the zone edge, reducing redundant blind broadcast.

Radius

The radius is a hop count, not physical distance. Larger radius means more local knowledge and more maintenance overhead.

Live topology

Source A is deciding how to reach a destination in a mobile ad-hoc network.

IERP + BRP
Zone Routing Protocol route decision animation A schematic network centered on source node A. Hop-count shells classify nodes as inside, peripheral, or outside the selected routing zone.
Source Interior zone Peripheral edge Outside zone Chosen route

Start with the remote destination scenario: A knows routes within two hops, so it must bordercast a route request to the zone edge.

Choose a routing question

Set the node-centric zone radius

Radius rho 2 hops

Animate the decision

Current readout

Destination R is outside A's 2-hop zone. IERP asks BRP to send route requests to the peripheral nodes rather than flooding every neighbor blindly.

1

Application asks Source A has a destination and checks whether the answer is already local.

2

IARP table Nodes within rho hops are table-driven and can be reached immediately.

3

BRP bordercast If the destination is outside, the query is directed to peripheral nodes.

4

IERP reply A node whose zone reaches the destination returns a route reply.

5

Data forwards The discovered path is used while the topology evidence still makes sense.

IARP zone table for source A

Node Hop count Next hop Use

BRP / IERP evidence

Route trace

Radius tradeoff

Read the colors

  • Green nodes are inside the proactive IARP zone.
  • Amber nodes are peripheral: exactly rho hops away.
  • Grey nodes require inter-zone discovery unless the radius grows.

What changes with radius

  • Radius 1 keeps a tiny table but discovers many destinations reactively.
  • Radius 2 balances local knowledge with limited discovery.
  • Radius 3 behaves more like a proactive protocol in this small topology.

Common mistakes

  • Routing zones are node-centric and overlap.
  • Radius is measured in hops, not metres.
  • Bordercast is targeted query forwarding, not blind network-wide flood.
Quick reference and technical notes

Protocol components

  • IARP: proactive intra-zone routes maintained around each node.
  • IERP: reactive inter-zone route discovery for destinations beyond the local zone.
  • BRP: bordercast mechanism that sends queries to zone-edge nodes and prunes redundant coverage.

Technical accuracy guardrails

  • ZRP is a MANET/ad-hoc routing framework, not the default routing protocol for Zigbee, Thread, BLE Mesh, or LoRaWAN.
  • Increasing radius can reduce discovery delay but increases proactive maintenance traffic.
  • High mobility can make a large zone expensive because local topology changes more often.

Try this

Set radius to 1 and remote destination R. Notice how quickly the proactive table shrinks and why discovery becomes more frequent.

Then compare

Set radius to 3. In this small topology, R may become reachable from A's local zone table, but the table is much larger.

Failure case

Enable the broken C-N link. The route can still be found through another edge path if the topology remains connected.

Technical basis: ZRP framework and terminology follow the IETF MANET ZRP draft and IERP draft descriptions of local proactive routing zones, inter-zone discovery, and bordercast query control.