From b6ecf4345016b4997da439a7cb28df637627f52d Mon Sep 17 00:00:00 2001
From: Michael Tuexen <tuexen@FreeBSD.org>
Date: Fri, 28 Apr 2017 15:38:34 +0000
Subject: [PATCH] Set the DF bit for responses to out-of-the-blue packets.

MFC after:	1 week
---
 sys/netinet/sctp_output.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sys/netinet/sctp_output.c b/sys/netinet/sctp_output.c
index 53657f4a07f..85d3053a658 100644
--- a/sys/netinet/sctp_output.c
+++ b/sys/netinet/sctp_output.c
@@ -11147,7 +11147,7 @@ sctp_send_resp_msg(struct sockaddr *src, struct sockaddr *dst,
 		ip->ip_v = IPVERSION;
 		ip->ip_hl = (sizeof(struct ip) >> 2);
 		ip->ip_tos = 0;
-		ip->ip_off = 0;
+		ip->ip_off = htons(IP_DF);
 		ip_fillid(ip);
 		ip->ip_ttl = MODULE_GLOBAL(ip_defttl);
 		if (port) {