diff -Naur libreswan-3.25-orig/include/pluto_constants.h libreswan-3.25/include/pluto_constants.h
--- libreswan-3.25-orig/include/pluto_constants.h	2018-06-27 11:42:26.000000000 -0400
+++ libreswan-3.25/include/pluto_constants.h	2019-02-15 17:41:06.954865678 -0500
@@ -436,6 +436,8 @@
 
 	IMPAIR_SEND_PKCS7_THINGIE_IX,		/* send certificates as a PKCS7 thingie */
 
+	IMPAIR_IKEv1_DEL_WITH_NOTIFY_IX,
+
 	IMPAIR_roof_IX	/* first unassigned IMPAIR */
 };
 
@@ -495,6 +497,7 @@
 
 #define IMPAIR_SEND_PKCS7_THINGIE		LELEM(IMPAIR_SEND_PKCS7_THINGIE_IX)
 
+#define IMPAIR_IKEv1_DEL_WITH_NOTIFY   LELEM(IMPAIR_IKEv1_DEL_WITH_NOTIFY_IX)
 /* State of exchanges
  *
  * The name of the state describes the last message sent, not the
diff -Naur libreswan-3.25-orig/lib/libswan/impair.c libreswan-3.25/lib/libswan/impair.c
--- libreswan-3.25-orig/lib/libswan/impair.c	2018-06-27 11:42:26.000000000 -0400
+++ libreswan-3.25/lib/libswan/impair.c	2019-02-15 17:41:06.954865678 -0500
@@ -75,6 +75,8 @@
 	I(IMPAIR_ALLOW_DNS_INSECURE, "impair-allow-dns-insecure"),
 
 	I(IMPAIR_SEND_PKCS7_THINGIE, "impair-send-pkcs7-thingie"),
+
+	I(IMPAIR_IKEv1_DEL_WITH_NOTIFY, "impair-ikev1-del-with-notify"),
 };
 
 const enum_names impair_names = {
diff -Naur libreswan-3.25-orig/programs/pluto/ikev1_main.c libreswan-3.25/programs/pluto/ikev1_main.c
--- libreswan-3.25-orig/programs/pluto/ikev1_main.c	2018-06-27 11:42:26.000000000 -0400
+++ libreswan-3.25/programs/pluto/ikev1_main.c	2019-02-15 17:42:50.876885416 -0500
@@ -2491,12 +2491,36 @@
 			isad.isad_protoid = ns->proto;
 
 			isad.isad_nospi = 1;
+
+			if (DBGP(IMPAIR_IKEv1_DEL_WITH_NOTIFY))
+				isad.isad_np = ISAKMP_NEXT_N; /* Notify */
+
 			passert(out_struct(&isad, &isakmp_delete_desc, &r_hdr_pbs,
 					   &del_pbs));
 			passert(out_raw(&ns->spi, sizeof(ipsec_spi_t),
 					&del_pbs,
 					"delete payload"));
 			close_output_pbs(&del_pbs);
+
+			if (DBGP(IMPAIR_IKEv1_DEL_WITH_NOTIFY)) {
+				pb_stream cruft_pbs;
+
+				libreswan_log("IMPAIR: adding bogus Notify payload after IKE Delete payload");
+				struct isakmp_notification isan = {
+					.isan_np = ISAKMP_NEXT_NONE,
+					.isan_doi = ISAKMP_DOI_IPSEC,
+					.isan_protoid = PROTO_ISAKMP,
+					.isan_spisize = COOKIE_SIZE * 2,
+					.isan_type = INVALID_PAYLOAD_TYPE,
+				};
+
+				passert(out_struct(&isan, &isakmp_notification_desc, &r_hdr_pbs,
+					&cruft_pbs));
+				passert(out_raw(&ns->spi, sizeof(ipsec_spi_t), &cruft_pbs,
+					"notify payload"));
+				close_output_pbs(&cruft_pbs);
+			}
+
 		}
 	}
 
@@ -2743,7 +2767,9 @@
 					rc->policy &= ~POLICY_UP;
 					if (!shared_phase1_connection(rc)) {
 						flush_pending_by_connection(rc);
+						/* This also deletes the IKE SA, clear pointer  */
 						delete_states_by_connection(rc, FALSE);
+						md->st = NULL;
 					}
 					reset_cur_connection();
 				}