A branch with a Branch Gateway can connect to two or more VPN hub sites, in a way that will provide either redundancy or load sharing.

In this topology, the Branch Gateway is connected through its 10/100 WAN Ethernet port to a DSL modem.

• Define two GRE Tunnel interfaces:

  • GRE1 that leads to a Primary Main Office GRE End Point behind the VPN Hub Gateway

  • GRE2 that leads to a Backup Main Office GRE End Point behind the VPN Hub Gateway

• Define two VPNs

• Connectivity to the networks in Primary/Backup Main Office is determined through GRE keepalives. If network connectivity is lost due to failures in the WAN, in the Primary Main Office, the GRE keep-alive will fail and the GRE interface will transition to a down state.