Index: head/sys/netinet6/in6_proto.c
===================================================================
--- head/sys/netinet6/in6_proto.c
+++ head/sys/netinet6/in6_proto.c
@@ -507,19 +507,21 @@
 
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_FORWARDING, forwarding,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_forwarding), 0,
-	"Enable IPv6 forwarding between interfaces");
+	"Enable forwarding of IPv6 packets between interfaces");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_SENDREDIRECTS, redirect,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_sendredirects), 0,
-	"Send a redirect message when forwarding back to a source link");
+	"Send ICMPv6 redirects for unforwardable IPv6 packets");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_DEFHLIM, hlim,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_defhlim), 0,
-	"Default hop limit");
+	"Default hop limit to use for outgoing IPv6 packets");
 SYSCTL_VNET_PCPUSTAT(_net_inet6_ip6, IPV6CTL_STATS, stats, struct ip6stat,
 	ip6stat,
 	"IP6 statistics (struct ip6stat, netinet6/ip6_var.h)");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_MAXFRAGPACKETS, maxfragpackets,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_maxfragpackets), 0,
-	"Maximum allowed number of outstanding fragmented IPv6 packets");
+	"Default maximum number of outstanding fragmented IPv6 packets. "
+	"A value of 0 means no fragmented packets will be accepted, while a "
+	"a value of -1 means no limit");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_ACCEPT_RTADV, accept_rtadv,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_accept_rtadv), 0,
 	"Default value of per-interface flag for accepting ICMPv6 RA messages");
@@ -541,7 +543,8 @@
 	"Frequency in seconds at which to log IPv6 forwarding errors");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_HDRNESTLIMIT, hdrnestlimit,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_hdrnestlimit), 0,
-	"Maximum allowed number of nested protocol headers");
+	"Default maximum number of IPv6 extension headers permitted on "
+	"incoming IPv6 packets, 0 for no artificial limit");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_DAD_COUNT, dad_count,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_dad_count), 0,
 	"Number of ICMPv6 NS messages sent during duplicate address detection");
@@ -550,7 +553,8 @@
 	"Provide an IPv6 flowlabel in outbound packets");
 SYSCTL_INT(_net_inet6_ip6, IPV6CTL_DEFMCASTHLIM, defmcasthlim,
 	CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_defmcasthlim), 0,
-	"Default hop limit for multicast packets");
+	"Default hop limit for IPv6 multicast packets originating from this "
+	"node");
 SYSCTL_STRING(_net_inet6_ip6, IPV6CTL_KAME_VERSION, kame_version,
 	CTLFLAG_RD, __KAME_VERSION, 0,
 	"KAME version string");