diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index f76d177895d960a50851937f5e317884d0f1444a..d71afa8bd82810d46e1e91f6275d8e2de3260176 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -15,12 +15,18 @@ ip_default_ttl - INTEGER
 	forwarded) IP packets. Should be between 1 and 255 inclusive.
 	Default: 64 (as recommended by RFC1700)
 
-ip_no_pmtu_disc - BOOLEAN
-	Disable Path MTU Discovery. If enabled and a
+ip_no_pmtu_disc - INTEGER
+	Disable Path MTU Discovery. If enabled in mode 1 and a
 	fragmentation-required ICMP is received, the PMTU to this
 	destination will be set to min_pmtu (see below). You will need
 	to raise min_pmtu to the smallest interface MTU on your system
 	manually if you want to avoid locally generated fragments.
+
+	In mode 2 incoming Path MTU Discovery messages will be
+	discarded. Outgoing frames are handled the same as in mode 1,
+	implicitly setting IP_PMTUDISC_DONT on every created socket.
+
+	Possible values: 0-2
 	Default: FALSE
 
 min_pmtu - INTEGER
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 1a4ee84ca3f3d9690e6860d031f67056de7a99d7..fb3c5637199dbfacd7b7b5c40ae14b1b2880d178 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -705,7 +705,9 @@ static void icmp_unreach(struct sk_buff *skb)
 		case ICMP_PORT_UNREACH:
 			break;
 		case ICMP_FRAG_NEEDED:
-			if (net->ipv4.sysctl_ip_no_pmtu_disc) {
+			if (net->ipv4.sysctl_ip_no_pmtu_disc == 2) {
+				goto out;
+			} else if (net->ipv4.sysctl_ip_no_pmtu_disc) {
 				LIMIT_NETDEBUG(KERN_INFO pr_fmt("%pI4: fragmentation needed and DF set\n"),
 					       &iph->daddr);
 			} else {