Draytek Vigor2862 Series User Manual page 247

Then confirm the WAN setup by seeing WAN online.
7. After all the functions are set properly on the primary router, we link up the
management interface LAN so both routers can start detecting each other, deciding
which one should be the primary and syncing the configuration. Since the routers will
communicate via the Management Interface, it's required to use the ports that belong to
the Management Interface LAN (LAN1 in this scenario). We can check for this
information in LAN >> VLAN. In this scenario we can use the port 5 on both routers, so we
use an Ethernet cable to wire up LAN port 5 on both routers.
8. We may check the High Availability status by visiting the Status page.
For the first time the two routers link up, we can see they are syncing the configuration
from the primary to the secondary (showing "Progressing" on the secondary router):
Vigor2862 Series User's Guide 231