diff --git a/contrib/tcpdump/print-icmp6.c b/contrib/tcpdump/print-icmp6.c
index 42fe19f2988..3b55cdc71a5 100644
--- a/contrib/tcpdump/print-icmp6.c
+++ b/contrib/tcpdump/print-icmp6.c
@@ -214,6 +214,7 @@ struct nd_router_advert {	/* router advertisement */
 #define ND_RA_FLAG_MANAGED	0x80
 #define ND_RA_FLAG_OTHER	0x40
 #define ND_RA_FLAG_HOME_AGENT	0x20
+#define ND_RA_FLAG_IPV6_ONLY	0x02
 
 /*
  * Router preference values based on draft-draves-ipngwg-router-selection-01.
@@ -545,6 +546,7 @@ static const struct tok icmp6_opt_ra_flag_values[] = {
     { ND_RA_FLAG_MANAGED, "managed" },
     { ND_RA_FLAG_OTHER, "other stateful"},
     { ND_RA_FLAG_HOME_AGENT, "home agent"},
+    { ND_RA_FLAG_IPV6_ONLY, "IPv6-Only"},
     { 0,	NULL }
 };
 
diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index 7d94bca57b2..6411085524c 100644
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -28,7 +28,7 @@
 .\"     From: @(#)ifconfig.8	8.3 (Berkeley) 1/5/94
 .\" $FreeBSD$
 .\"
-.Dd June 27, 2018
+.Dd February 24, 2019
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -770,6 +770,12 @@ When this flag is cleared and
 .Cm auto_linklocal
 flag is enabled, automatic configuration of a link-local address is
 performed.
+.It Cm ipv6_only
+Set a flag to manually disable sending and receiving IPv4 protocol
+packets.
+.It Cm -ipv6_only
+Clear the flag
+.Cm ipv6_only .
 .It Cm nud
 Set a flag to enable Neighbor Unreachability Detection.
 .It Cm -nud