Ipsec
A regional internal IP address range reserved for the VLAN attachment that is used in HA VPN over Cloud Interconnect. This regional internal IP address range must not overlap with any IP address range of subnet/route in the VPC network and its peering networks. After the VLAN attachment is created with the reserved IP address range, when creating a new VPN gateway, its interface IP address is allocated from the associated VLAN attachment’s IP address range.