---
title: Understanding transitive peering
description: This page helps users understand how transitivity works when using Scaleway VPC Peering.
tags: peering transitivity daisy chained hub spoke
dates:
  validation: 2026-06-22
  posted: 2026-05-18
---

import peeringSimple from './assets/scaleway-vpc-peering-simple-co.webp'
import peeringNoTransitivity3 from './assets/scaleway-vpc-peering-no-transitivity-3.webp'
import peeringTransitivity3 from './assets/scaleway-vpc-peering-transitivity-3.webp'
import peeringNoTransitivity4 from './assets/scaleway-vpc-peering-no-transitivity-4.webp'
import peeringTransitivity4 from './assets/scaleway-vpc-peering-transitivity-4.webp'
import peeringFullTransitivity from './assets/scaleway-vpc-peering-full-transitivity-4.webp'

## Overview

Transitive peering (or transitive routing) allows two VPCs that are not directly peered to exchange traffic through a third VPC that is peered with both. Traffic is forwarded through this intermediate network, making the connection transitive.

Transitive peering is disabled by default. It must be [enabled on the intermediary VPC](/vpc/how-to/create-vpc/#how-to-create-a-vpc) (the VPC that forwards traffic between the two others) when that VPC is created. Only intermediary VPCs require transitive peering to be enabled, and this setting cannot be disabled after the VPC is created.

To enable transitivity, you must also [define custom routes](/vpc/how-to/manage-routing/#how-to-create-a-custom-route) in each VPC of the chain.

For example, if VPC A is peered with both VPC B and VPC C, you can route traffic between VPC B and VPC C through VPC A. As the intermediary, VPC A must have transitive peering enabled. To route the traffic, define a custom route in VPC B directing traffic to VPC C via VPC A, and a corresponding route in VPC C directing traffic to VPC B via VPC A.

<Message type="note">
As routing complexity increases with each additional VPC in the transitivity chain, transitive peering is limited to four chained VPCs.
</Message>

## Examples

**Simple peering connection**

With two VPCs, there is no routing transitivity: a single VPC Peering connection is enough for VPC A to communicate with VPC B.

<Lightbox image={peeringSimple} alt="A graphic shows how two different VPCs each create a peering connector, which enables them to communicate over a peering connection." />

**Three peered VPCs without transitivity**

With three chained VPCs, if you only add routes related to the next peer, then VPC A and B can communicate, and VPC B and C can communicate, but VPC A and C cannot.

<Lightbox image={peeringNoTransitivity3} alt="A graphic shows how three different VPCs each create a peering connector, which enables them to communicate over a peering connection with neighboring VPCs, but not via a common VPC." />

**Three peered VPCs with transitivity**

To enable VPC A and C to communicate with each other, you must add corresponding routes.

<Lightbox image={peeringTransitivity3} alt="A graphic shows how three different VPCs each create a peering connector, which enables them to communicate over a peering connection with neighboring VPCs, and via a common VPC by adding corresponding custom routes." />

**Four peered VPCs without transitivity**

With four chained VPCs, if you only add routes related to the next peer, then each VPC is only able to communicate with its immediate neighbors.

<Lightbox image={peeringNoTransitivity4} alt="A graphic shows how four different VPCs each create a peering connector, which enables them to communicate over a peering connection with neighboring VPCs, but not via a common VPC." />

**Four peered VPCs with partial transitivity**

To enable VPC A and D to communicate with each other, you must add corresponding routes. This also includes custom routes in VPC B and C, which must have a path to each extremity of the chain.

<Lightbox image={peeringTransitivity4} alt="A graphic shows how four different VPCs each create a peering connector, which enables them to communicate over a peering connection with neighboring VPCs, and via a common VPC by adding corresponding custom routes." />

**Four peered VPCs with full transitivity**

To enable full transitivity and allow any two VPCs of the chain to communicate, you must add additional routes to VPCs A and D.

<Lightbox image={peeringFullTransitivity} alt="A graphic shows how four different VPCs each create a peering connector, which enables them to communicate with any other VPC by adding custom routes to each VPC to enable full transitivity." />