Do VPNs Have the DPD Function Enabled?

Yes.

By default, the dead peer detection (DPD) function is enabled for VPNs to detect the state of the IKE process in an on-premises data center.

After three consecutive detection failures, the IKE process in the on-premises data center is considered abnormal, and the tunnel on the cloud is automatically deleted.

The DPD protocol does not require that the peer end also be configured with DPD, but it requires that the peer end be able to respond to DPD detections. To ensure consistent tunnel states at the two ends, it is recommended that you enable DPD on your on-premises gateway to detect the IKE process state of the VPN service.

After DPD fails, the tunnel will be deleted without affecting service stability.

DPD can detect exceptions in the IKE process at the peer end in time and reset the tunnel to ensure tunnel synchronization between the two ends. After a tunnel is deleted, if there is traffic transmitted over the tunnel, the tunnel can be re-established through negotiation.