diff -Naur libreswan-3.15-orig/programs/pluto/ikev2.c libreswan-3.15/programs/pluto/ikev2.c
--- libreswan-3.15-orig/programs/pluto/ikev2.c	2016-09-07 10:10:59.477000000 -0400
+++ libreswan-3.15/programs/pluto/ikev2.c	2016-09-07 10:14:14.222000000 -0400
@@ -73,13 +73,6 @@
 
 #include "plutoalg.h" /* for default_ike_groups */
 
-/* Note: same definition appears in programs/pluto/ikev2_parent.c */
-#define SEND_V2_NOTIFICATION(t) { \
-		if (st != NULL) \
-			send_v2_notification_from_state(st, t, NULL); \
-		else \
-			send_v2_notification_from_md(md, t, NULL); }
-
 enum smf2_flags {
 	/*
 	 * Check the value of the IKE_I flag in the header.
@@ -400,16 +393,6 @@
 	 *   <--  HDR, SK {[N,] [D,] [CP], ...}
 	 */
 
-	{ .story      = "I2: process INFORMATIONAL",
-	  .state      = STATE_PARENT_I2,
-	  .next_state = STATE_PARENT_I2,
-	  .flags      = SMF2_IKE_I_CLEAR,
-	  .req_clear_payloads = P(SK),
-	  .opt_enc_payloads = P(N) | P(D) | P(CP),
-	  .processor  = process_encrypted_informational_ikev2,
-	  .recv_type  = ISAKMP_v2_INFORMATIONAL,
-	  .timeout_event = EVENT_RETAIN, },
-
 	{ .story      = "I3: INFORMATIONAL",
 	  .state      = STATE_PARENT_I3,
 	  .next_state = STATE_PARENT_I3,
@@ -420,16 +403,6 @@
 	  .recv_type  = ISAKMP_v2_INFORMATIONAL,
 	  .timeout_event = EVENT_RETAIN, },
 
-	{ .story      = "R1: process INFORMATIONAL",
-	  .state      = STATE_PARENT_R1,
-	  .next_state = STATE_PARENT_R1,
-	  .flags      = SMF2_IKE_I_SET,
-	  .req_clear_payloads = P(SK),
-	  .opt_enc_payloads = P(N) | P(D) | P(CP),
-	  .processor  = process_encrypted_informational_ikev2,
-	  .recv_type  = ISAKMP_v2_INFORMATIONAL,
-	  .timeout_event = EVENT_RETAIN, },
-
 	{ .story      = "R2: process INFORMATIONAL",
 	  .state      = STATE_PARENT_R2,
 	  .next_state = STATE_PARENT_R2,
@@ -1061,7 +1034,7 @@
 			 * XXX: Returning INVALID_MESSAGE_ID seems
 			 * pretty bogus.
 			 */
-			SEND_V2_NOTIFICATION(v2N_INVALID_MESSAGE_ID);
+			SEND_V2_NOTIFICATION(v2N_INVALID_IKE_SPI);
 		}
 		return;
 	}
@@ -1353,6 +1326,7 @@
 	st.st_localport  = md->iface->port;
 	cnx.interface = md->iface;
 	st.st_interface = md->iface;
+	st.st_reply_xchg = md->hdr.isa_xchg;
 
 	send_v2_notification(&st, type, NULL,
 			     md->hdr.isa_icookie, md->hdr.isa_rcookie, data);
diff -Naur libreswan-3.15-orig/programs/pluto/ikev2.h libreswan-3.15/programs/pluto/ikev2.h
--- libreswan-3.15-orig/programs/pluto/ikev2.h	2015-08-24 22:28:32.000000000 -0400
+++ libreswan-3.15/programs/pluto/ikev2.h	2016-09-07 10:12:30.357000000 -0400
@@ -235,3 +235,9 @@
 void ikev2_log_payload_errors(struct ikev2_payload_errors errors,
 			      struct state *st);
 
+#define SEND_V2_NOTIFICATION(t) { \
+	if (st != NULL) \
+		send_v2_notification_from_state(st, t, NULL); \
+	else \
+		send_v2_notification_from_md(md, t, NULL); }
+
diff -Naur libreswan-3.15-orig/programs/pluto/ikev2_parent.c libreswan-3.15/programs/pluto/ikev2_parent.c
--- libreswan-3.15-orig/programs/pluto/ikev2_parent.c	2016-09-07 10:10:59.478000000 -0400
+++ libreswan-3.15/programs/pluto/ikev2_parent.c	2016-09-07 10:12:30.357000000 -0400
@@ -70,14 +70,6 @@
 
 #include "ietf_constants.h"
 
-/* Note: same definition appears in programs/pluto/ikev2.c */
-#define SEND_V2_NOTIFICATION(t) { \
-		if (st != NULL) \
-			send_v2_notification_from_state(st, t, NULL); \
-		else \
-			send_v2_notification_from_md(md, t, NULL); \
-	}
-
 #ifdef XAUTH_HAVE_PAM
 struct ikev2_pam_helper {
 	struct pam_thread_arg pam;	/* writable inside thread */
@@ -3628,6 +3620,8 @@
 			hdr.isa_xchg = ISAKMP_v2_SA_INIT;
 			break;
 		}
+		if (p1st->st_reply_xchg != 0)
+			hdr.isa_xchg = p1st->st_reply_xchg; /* use received exchange type */
 
 		hdr.isa_np = ISAKMP_NEXT_v2N;
 		/* XXX unconditionally clearing original initiator flag is wrong */
diff -Naur libreswan-3.15-orig/programs/pluto/state.h libreswan-3.15/programs/pluto/state.h
--- libreswan-3.15-orig/programs/pluto/state.h	2015-08-24 22:28:32.000000000 -0400
+++ libreswan-3.15/programs/pluto/state.h	2016-09-07 10:14:43.847000000 -0400
@@ -480,6 +480,7 @@
 	bool st_xauth_soft;                     /* XAUTH failed but policy is to soft fail */
 	bool st_seen_fragvid;                   /* should really use st_seen_vendorid, but no one else is */
 	bool st_seen_fragments;                 /* did we receive ike fragments from peer, if so use them in return as well */
+	u_int8_t st_reply_xchg;
 };
 
 /* global variables */