Using BGP communities with Site-to-Site VPN

Reviewed on September 30, 2025

A Border Gateway Protocol (BGP) community is a group of IP prefixes that share a common attribute.

Scaleway recognizes 3 BGP communities, and applies routing priorities based on the community applied. This lets you influence routing between the various InterLinks or Site-to-Site VPN connections in a VPC, for traffic flowing from Scaleway to your external network.

For each prefix that you advertise from your external/on-premises router over a BGP session, you can apply one of the following community tags to indicate the priority of the associated path for returning traffic:

• 12876:42050 — Low preference
• 12876:42100 — Medium preference
• 12876:42200 — High preference

These BGP communities are evaluated in order from lowest to highest preference, where the highest preference takes priority. They are mutually exclusive, meaning you can only apply one of them per prefix.

To apply these communities, you must configure your BGP router or software to add the appropriate community to the routes you advertise.

You cannot add communities to prefixes advertised by your Scaleway VPC toward your external/on-premises router.

Default routing priority

When no BGP communities are applied, the default routing priority observes the following behavior:

• InterLink routes have the highest priority
• Site-to-Site VPN routes have lower priority

This means that if both InterLink and Site-to-Site VPN connections are configured on the same VPC and advertise the same prefixes without BGP communities, traffic will preferentially flow through the InterLink connection.

To override this default behavior and influence traffic routing, apply the appropriate BGP community tags to your advertised prefixes.