Take V300R019 as an example.
In dual-Hub DSVPN scenario, the backup Hub only forwards data after the master Hub fails. No tunnel can be established between the Spokes.
Check whether the public addresses configured on the master and backup Hubs are on the same network segment.
Run the display this command on the mGRE interfaces of the master and backup Hubs to check whether the IP addresses of the Hubs are on the same network segment.
If so, change the IP address of one Hub to an IP address on a different network segment.
If not, go to step 2.
Check whether routes to the master Hub are available on the Spokes.
Run the display ip routing-table command on the Spokes to check whether routes to the Hub exist.
If the IP routing table contains routes to the master Hub, delete the routes. For details, see Huawei AR Series V300R019 Configuration Guide - IP Routing.
