The [Xfrm] section accepts the following keys:
InterfaceId=
Sets the ID/key of the xfrm interface which needs to be
associated with a SA/policy. Can be decimal or hexadecimal,
valid range is 0-0xffffffff, defaults to 0.
Independent=
Takes a boolean. If false (the default), the xfrm interface
must have an underlying device which can be used for hardware
offloading.
For more detail information see Virtual XFRM Interfaces
