Support syncRemoteAddressSpace for virtual network peerings

[acortelyou]

Context

When managing Azure Virtual Network Peerings with Bicep, updating a VNet’s addressSpace often leaves the peering in an “Out of Sync” state in the Azure Portal. The official guidance says:

“When you update the address space for a virtual network, you need to sync the virtual network peer for each remote peered virtual network.”

Currently, re‑deploying the peering resource via Bicep (or ARM) does not trigger this sync. The Portal still shows Remote not in sync until an explicit sync action is performed.

Current Limitation

• The sync operation is exposed as an action, not a property.
• The REST API supports ?syncRemoteAddressSpace=true as a query parameter on the PUT request.
• Bicep/ARM templates only control the request body, so there is no way to declaratively include this query parameter.
• Properties like remoteVirtualNetworkAddressSpace and peerCompleteVnets are read‑only and cannot be set in Bicep.

Impact

• Infrastructure‑as‑Code workflows cannot fully reconcile peering state after address space changes without adding imperative steps (CLI, PowerShell, or deployment scripts).
• This breaks the declarative model and complicates automation for production environments.

Feature Request

Add a mechanism in Bicep (and ARM) to declaratively trigger the sync operation during peering updates. Possible approaches:

• Support a boolean property (e.g., syncRemoteAddressSpace: true) that maps internally to the query parameter.
• Support a boolean decorator (e.g. @syncRemoteAddressSpace(true) or @queryParameter({syncRemoteAddressSpace: true}) that maps to the query parameter
• Or introduce an ARM/Bicep extension for resource actions so that sync can be expressed in the template.

Why It Matters

• Keeps network peering management fully declarative.
• Eliminates the need for imperative deployment scripts.
• Aligns with the principle of idempotent infrastructure deployments.

[stephaniezyen]

This is unfortunately something we are not planning to support in Bicep, please reach out to the Microsoft.Network team for this ask.

[acortelyou]

@stephaniezyen Are you aware of any similar scenarios which have a solution or is there an bicep pattern that I can point them to when I reach out?

What is the desired behavior from bicep's perspective?

Most other resources reconcile when you touch them without any extra prompting.