Peer ASN AS271609 already exists with different name and cannot be associated with Azure subscription

Hello,

We are Vixel Telecom, operator of public ASN AS271609.

We are trying to associate AS271609 with our Azure subscription "Peering Vixel" in order to request IPv4 and IPv6 Exchange Peering with Microsoft AS8075 at IX.br São Paulo, Brazil.

When creating the Microsoft.Peering/peerAsns resource, the Azure deployment fails with the following error:

Peer ASN already exists with different name

We checked all Azure subscriptions available in our current tenant using Azure CLI:

az peering asn list -o table

The command returns no PeerAsn resources in either subscription.

We also explicitly switched between both subscriptions and repeated the command, with the same result.

This suggests that AS271609 may already have an existing PeerAsn registration under another resource name, subscription, tenant, or legacy Microsoft Peering association.

Could a Microsoft engineer please help identify the existing PeerAsn registration and advise how we can recover, transfer, or reassociate AS271609 with our current Azure subscription?

Our intended configuration is:

• ASN: AS271609
• Network: Vixel Telecom
• Peering type: Exchange Peering
• Microsoft ASN: AS8075
• Internet Exchange: IX.br São Paulo
• Protocols: IPv4 and IPv6

This is specifically a PeerAsn association issue. We are not requesting Azure Peering Service partner onboarding, ExpressRoute, or Direct Peering.

We can provide PeeringDB, WHOIS/IRR information and proof of control of AS271609 if required.

Thank you.