services.strongswan-swanctl.swanctl.connections.<name>.children.<name>.if_id_in

XFRM interface ID set on inbound policies/SA. This allows installing duplicate policies/SAs and associates them with an interface with the same ID. The special value %unique sets a unique interface ID on each CHILD_SA instance, beyond that the value %unique-dir assigns a different unique interface ID for each CHILD_SA direction (in/out).

StrongSwan default: "0"