If unsure, say Y.
+config XFRM_INTERFACE
+ tristate "Transformation virtual interface"
+ depends on XFRM && IPV6
+ ---help---
+ This provides a virtual interface to route IPsec traffic.
+
+ If unsure, say N.
+
config XFRM_SUB_POLICY
bool "Transformation sub policy support"
depends on XFRM