Index: sys/netinet/tcp_timewait.c
===================================================================
--- sys/netinet/tcp_timewait.c
+++ sys/netinet/tcp_timewait.c
@@ -225,6 +225,7 @@
 {
 	struct tcptw *tw;
 	struct inpcb *inp = tp->t_inpcb;
+	struct tcptemp *t_template;
 	int acknow;
 	struct socket *so;
 #ifdef INET6
@@ -238,6 +239,16 @@
 	KASSERT((inp->inp_flags & INP_DROPPED) == 0, ("tcp_twstart: "
 	    "(inp->inp_flags & INP_DROPPED) != 0"));
 
+	acknow = tp->t_flags & TF_ACKNOW;
+	if (acknow) {
+		t_template = tcpip_maketemplate(inp);
+		if (t_template != NULL) {
+			tcp_respond(tp, t_template->tt_ipgen, &t_template->tt_t,
+			    (struct mbuf *)NULL, tp->rcv_nxt, tp->snd_una, 0);
+			free(t_template, M_TEMP);
+			acknow = 0;
+		}
+	}
 	if (V_nolocaltimewait) {
 		int error = 0;
 #ifdef INET6
@@ -316,13 +327,6 @@
 	tw->irs     = tp->irs;
 	tw->t_starttime = tp->t_starttime;
 	tw->tw_time = 0;
-
-/* XXX
- * If this code will
- * be used for fin-wait-2 state also, then we may need
- * a ts_recent from the last segment.
- */
-	acknow = tp->t_flags & TF_ACKNOW;
 
 	/*
 	 * First, discard tcpcb state, which includes stopping its timers and