+ IPv6AddressMode:
+ default: dhcpv6-stateful
+ description: Neutron subnet IPv6 address mode
+ type: string
+ IPv6RAMode:
+ default: dhcpv6-stateful
+ description: Neutron subnet IPv6 router advertisement mode
+ type: string
+ ExternalInterfaceDefaultRoute:
+ default: '2001:db8:fd00:1000::1'
+ description: default route for the external network
+ type: string