Azure Relay: No Inbound Ports Needed

Frequently asked questions

How does Azure Relay reach an on-premises service without an open inbound port?

The on-premises (private) side makes the outbound connection to a rendezvous point in Azure — the cloud side never initiates an inbound connection, so no firewall rule needs to be opened for it.

When would you use Relay instead of a VPN?

Relay suits reaching a single specific on-prem service without standing up full network-level connectivity. When more than a request/response link is needed, or the two sides don't need to be online at the same time, a VPN or a queue can be the better fit.

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