diff --git a/configure b/configure
index cd89b5726c..9ea0cf99a7 100755
--- a/configure
+++ b/configure
@@ -748,16 +748,11 @@ ISC_PLATFORM_NEEDNTOP
 ISC_PLATFORM_HAVEIF_LADDRCONF
 ISC_PLATFORM_HAVEIF_LADDRREQ
 ISC_PLATFORM_HAVESCOPEID
-ISC_IPV6_C
-ISC_ISCIPV6_O
-ISC_IPV6_O
-ISC_IPV6_H
 ISC_PLATFORM_HAVESOCKADDRSTORAGE
 ISC_PLATFORM_HAVEIN6PKTINFO
 ISC_PLATFORM_NEEDIN6ADDRLOOPBACK
 ISC_PLATFORM_NEEDIN6ADDRANY
 ISC_PLATFORM_HAVEINADDR6
-ISC_PLATFORM_HAVEIPV6
 BIND9_CO_RULE
 LIBTOOL_ALLOW_UNDEFINED
 LIBTOOL_MODE_UNINSTALL
@@ -17845,13 +17840,16 @@ $as_echo_n "checking for IPv6 structures... " >&6; }
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+
 int
 main ()
 {
-struct sockaddr_in6 sin6; return (0);
+
+       struct sockaddr_in6 sin6; return (0);
+
   ;
   return 0;
 }
@@ -17859,11 +17857,11 @@ _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
-	 found_ipv6=yes
 else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-	 found_ipv6=no
+  { { $as_echo "$as_me:${as_lineno-$LINENO}: error: in \`$ac_pwd':" >&5
+$as_echo "$as_me: error: in \`$ac_pwd':" >&2;}
+as_fn_error $? "IPv6 support is mandatory
+See \`config.log' for more details" "$LINENO" 5; }
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
@@ -17914,26 +17912,21 @@ Please choose the proper path with the following command:
 		;;
 esac
 
-#
-# Now delve deeper into the suitability of the IPv6 support.
-#
-case "$found_ipv6" in
-	yes)
-		ISC_PLATFORM_HAVEIPV6="#define ISC_PLATFORM_HAVEIPV6 1"
-
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6_addr" >&5
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6_addr" >&5
 $as_echo_n "checking for in6_addr... " >&6; }
-		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
 
 int
 main ()
 {
-struct in6_addr in6; return (0);
+
+       struct in6_addr in6; return (0);
+
   ;
   return 0;
 }
@@ -17941,89 +17934,32 @@ _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
-		 ISC_PLATFORM_HAVEINADDR6="#undef ISC_PLATFORM_HAVEINADDR6"
-		 isc_in_addr6_hack=""
+   ISC_PLATFORM_HAVEINADDR6="#undef ISC_PLATFORM_HAVEINADDR6"
+   isc_in_addr6_hack=""
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
-		 ISC_PLATFORM_HAVEINADDR6="#define ISC_PLATFORM_HAVEINADDR6 1"
-		 isc_in_addr6_hack="#define in6_addr in_addr6"
+   ISC_PLATFORM_HAVEINADDR6="#define ISC_PLATFORM_HAVEINADDR6 1"
+   isc_in_addr6_hack="#define in6_addr in_addr6"
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6addr_any" >&5
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6addr_any" >&5
 $as_echo_n "checking for in6addr_any... " >&6; }
-		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-$isc_in_addr6_hack
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+       $isc_in_addr6_hack
 
 int
 main ()
 {
-struct in6_addr in6; in6 = in6addr_any; return (in6.s6_addr[0]);
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-			 ISC_PLATFORM_NEEDIN6ADDRANY="#undef ISC_PLATFORM_NEEDIN6ADDRANY"
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-			 ISC_PLATFORM_NEEDIN6ADDRANY="#define ISC_PLATFORM_NEEDIN6ADDRANY 1"
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
 
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6addr_loopback" >&5
-$as_echo_n "checking for in6addr_loopback... " >&6; }
-		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
+       struct in6_addr in6; in6 = in6addr_any; return (in6.s6_addr[0]);
 
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-$isc_in_addr6_hack
-
-int
-main ()
-{
-struct in6_addr in6; in6 = in6addr_loopback; return (in6.s6_addr[0]);
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-$as_echo "yes" >&6; }
-			 ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#undef ISC_PLATFORM_NEEDIN6ADDRLOOPBACK"
-else
-  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
-$as_echo "no" >&6; }
-			 ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#define ISC_PLATFORM_NEEDIN6ADDRLOOPBACK 1"
-fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for sin6_scope_id in struct sockaddr_in6" >&5
-$as_echo_n "checking for sin6_scope_id in struct sockaddr_in6... " >&6; }
-		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-
-int
-main ()
-{
-struct sockaddr_in6 xyzzy; xyzzy.sin6_scope_id = 0; return (0);
   ;
   return 0;
 }
@@ -18031,27 +17967,30 @@ _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
-			 ISC_PLATFORM_HAVESCOPEID="#define ISC_PLATFORM_HAVESCOPEID 1"
+   ISC_PLATFORM_NEEDIN6ADDRANY="#undef ISC_PLATFORM_NEEDIN6ADDRANY"
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
-			 ISC_PLATFORM_HAVESCOPEID="#undef ISC_PLATFORM_HAVESCOPEID"
+   ISC_PLATFORM_NEEDIN6ADDRANY="#define ISC_PLATFORM_NEEDIN6ADDRANY 1"
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
-		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6_pktinfo" >&5
-$as_echo_n "checking for in6_pktinfo... " >&6; }
-		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6addr_loopback" >&5
+$as_echo_n "checking for in6addr_loopback... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
 
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+       $isc_in_addr6_hack
 
 int
 main ()
 {
-struct in6_pktinfo xyzzy; return (0);
+
+       struct in6_addr in6; in6 = in6addr_loopback; return (in6.s6_addr[0]);
+
   ;
   return 0;
 }
@@ -18059,25 +17998,73 @@ _ACEOF
 if ac_fn_c_try_compile "$LINENO"; then :
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
-			 ISC_PLATFORM_HAVEIN6PKTINFO="#define ISC_PLATFORM_HAVEIN6PKTINFO 1"
+   ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#undef ISC_PLATFORM_NEEDIN6ADDRLOOPBACK"
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+   ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#define ISC_PLATFORM_NEEDIN6ADDRLOOPBACK 1"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for sin6_scope_id in struct sockaddr_in6" >&5
+$as_echo_n "checking for sin6_scope_id in struct sockaddr_in6... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+
+int
+main ()
+{
+
+       struct sockaddr_in6 xyzzy; xyzzy.sin6_scope_id = 0; return (0);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+   ISC_PLATFORM_HAVESCOPEID="#define ISC_PLATFORM_HAVESCOPEID 1"
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+   ISC_PLATFORM_HAVESCOPEID="#undef ISC_PLATFORM_HAVESCOPEID"
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for in6_pktinfo" >&5
+$as_echo_n "checking for in6_pktinfo... " >&6; }
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+
+int
+main ()
+{
+
+       struct in6_pktinfo xyzzy; return (0);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+   ISC_PLATFORM_HAVEIN6PKTINFO="#define ISC_PLATFORM_HAVEIN6PKTINFO 1"
 else
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no -- disabling runtime ipv6 support" >&5
 $as_echo "no -- disabling runtime ipv6 support" >&6; }
-			 ISC_PLATFORM_HAVEIN6PKTINFO="#undef ISC_PLATFORM_HAVEIN6PKTINFO"
+   ISC_PLATFORM_HAVEIN6PKTINFO="#undef ISC_PLATFORM_HAVEIN6PKTINFO"
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-		;;
-	no)
-		ISC_PLATFORM_HAVEIPV6="#undef ISC_PLATFORM_HAVEIPV6"
-		ISC_PLATFORM_NEEDIN6ADDRANY="#undef ISC_PLATFORM_NEEDIN6ADDRANY"
-		ISC_PLATFORM_HAVEIN6PKTINFO="#undef ISC_PLATFORM_HAVEIN6PKTINFO"
-		ISC_PLATFORM_HAVESCOPEID="#define ISC_PLATFORM_HAVESCOPEID 1"
-		ISC_IPV6_H="ipv6.h"
-		ISC_IPV6_O="ipv6.$O"
-		ISC_ISCIPV6_O="unix/ipv6.$O"
-		ISC_IPV6_C="ipv6.c"
-		;;
-esac
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for struct sockaddr_storage" >&5
 $as_echo_n "checking for struct sockaddr_storage... " >&6; }
@@ -18114,11 +18101,6 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
 
 
 
-
-
-
-
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for struct if_laddrreq" >&5
 $as_echo_n "checking for struct if_laddrreq... " >&6; }
 cat confdefs.h - <<_ACEOF >conftest.$ac_ext
diff --git a/configure.in b/configure.in
index c77651a57e..2dbb8fc586 100644
--- a/configure.in
+++ b/configure.in
@@ -1934,16 +1934,19 @@ AC_SUBST(BIND9_CO_RULE)
 # We do the IPv6 compilation checking after libtool so that we can put
 # the right suffix on the files.
 #
-AC_MSG_CHECKING(for IPv6 structures)
-AC_TRY_COMPILE([
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>],
-[struct sockaddr_in6 sin6; return (0);],
-	[AC_MSG_RESULT(yes)
-	 found_ipv6=yes],
-	[AC_MSG_RESULT(no)
-	 found_ipv6=no])
+AC_MSG_CHECKING([for IPv6 structures])
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM(
+     [[
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+     ]],
+     [[
+       struct sockaddr_in6 sin6; return (0);
+     ]])],
+  [AC_MSG_RESULT([yes])],
+  [AC_MSG_FAILURE([IPv6 support is mandatory])])
 
 #
 # See whether IPv6 support is provided via a Kame add-on.
@@ -1985,88 +1988,89 @@ Please choose the proper path with the following command:
 		;;
 esac
 
-#
-# Now delve deeper into the suitability of the IPv6 support.
-#
-case "$found_ipv6" in
-	yes)
-		ISC_PLATFORM_HAVEIPV6="#define ISC_PLATFORM_HAVEIPV6 1"
+AC_MSG_CHECKING([for in6_addr])
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM(
+     [[
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+     ]],
+     [[
+       struct in6_addr in6; return (0);
+     ]])],
+  [AC_MSG_RESULT([yes])
+   ISC_PLATFORM_HAVEINADDR6="#undef ISC_PLATFORM_HAVEINADDR6"
+   isc_in_addr6_hack=""],
+  [AC_MSG_RESULT([no])
+   ISC_PLATFORM_HAVEINADDR6="#define ISC_PLATFORM_HAVEINADDR6 1"
+   isc_in_addr6_hack="#define in6_addr in_addr6"])
 
-		AC_MSG_CHECKING(for in6_addr)
-		AC_TRY_COMPILE([
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-],
-[struct in6_addr in6; return (0);],
-		[AC_MSG_RESULT(yes)
-		 ISC_PLATFORM_HAVEINADDR6="#undef ISC_PLATFORM_HAVEINADDR6"
-		 isc_in_addr6_hack=""],
-		[AC_MSG_RESULT(no)
-		 ISC_PLATFORM_HAVEINADDR6="#define ISC_PLATFORM_HAVEINADDR6 1"
-		 isc_in_addr6_hack="#define in6_addr in_addr6"])
+AC_MSG_CHECKING([for in6addr_any])
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM(
+     [[
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+       $isc_in_addr6_hack
+     ]],
+     [[
+       struct in6_addr in6; in6 = in6addr_any; return (in6.s6_addr[0]);
+     ]])],
+  [AC_MSG_RESULT([yes])
+   ISC_PLATFORM_NEEDIN6ADDRANY="#undef ISC_PLATFORM_NEEDIN6ADDRANY"],
+  [AC_MSG_RESULT([no])
+   ISC_PLATFORM_NEEDIN6ADDRANY="#define ISC_PLATFORM_NEEDIN6ADDRANY 1"])
 
-		AC_MSG_CHECKING(for in6addr_any)
-		AC_TRY_LINK([
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-$isc_in_addr6_hack
-],
-		[struct in6_addr in6; in6 = in6addr_any; return (in6.s6_addr[0]);],
-			[AC_MSG_RESULT(yes)
-			 ISC_PLATFORM_NEEDIN6ADDRANY="#undef ISC_PLATFORM_NEEDIN6ADDRANY"],
-			[AC_MSG_RESULT(no)
-			 ISC_PLATFORM_NEEDIN6ADDRANY="#define ISC_PLATFORM_NEEDIN6ADDRANY 1"])
+AC_MSG_CHECKING([for in6addr_loopback])
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM(
+     [[
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+       $isc_in_addr6_hack
+     ]],
+     [[
+       struct in6_addr in6; in6 = in6addr_loopback; return (in6.s6_addr[0]);
+     ]])],
+  [AC_MSG_RESULT(yes)
+   ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#undef ISC_PLATFORM_NEEDIN6ADDRLOOPBACK"],
+  [AC_MSG_RESULT(no)
+   ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#define ISC_PLATFORM_NEEDIN6ADDRLOOPBACK 1"])
 
-		AC_MSG_CHECKING(for in6addr_loopback)
-		AC_TRY_LINK([
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-$isc_in_addr6_hack
-],
-		[struct in6_addr in6; in6 = in6addr_loopback; return (in6.s6_addr[0]);],
-			[AC_MSG_RESULT(yes)
-			 ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#undef ISC_PLATFORM_NEEDIN6ADDRLOOPBACK"],
-			[AC_MSG_RESULT(no)
-			 ISC_PLATFORM_NEEDIN6ADDRLOOPBACK="#define ISC_PLATFORM_NEEDIN6ADDRLOOPBACK 1"])
+AC_MSG_CHECKING([for sin6_scope_id in struct sockaddr_in6])
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM(
+     [[
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+     ]],
+     [[
+       struct sockaddr_in6 xyzzy; xyzzy.sin6_scope_id = 0; return (0);
+     ]])],
+  [AC_MSG_RESULT([yes])
+   ISC_PLATFORM_HAVESCOPEID="#define ISC_PLATFORM_HAVESCOPEID 1"],
+  [AC_MSG_RESULT([no])
+   ISC_PLATFORM_HAVESCOPEID="#undef ISC_PLATFORM_HAVESCOPEID"])
 
-		AC_MSG_CHECKING(for sin6_scope_id in struct sockaddr_in6)
-		AC_TRY_COMPILE([
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-],
-		[struct sockaddr_in6 xyzzy; xyzzy.sin6_scope_id = 0; return (0);],
-			[AC_MSG_RESULT(yes)
-			 ISC_PLATFORM_HAVESCOPEID="#define ISC_PLATFORM_HAVESCOPEID 1"],
-			[AC_MSG_RESULT(no)
-			 ISC_PLATFORM_HAVESCOPEID="#undef ISC_PLATFORM_HAVESCOPEID"])
-
-		AC_MSG_CHECKING(for in6_pktinfo)
-		AC_TRY_COMPILE([
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-],
-		[struct in6_pktinfo xyzzy; return (0);],
-			[AC_MSG_RESULT(yes)
-			 ISC_PLATFORM_HAVEIN6PKTINFO="#define ISC_PLATFORM_HAVEIN6PKTINFO 1"],
-			[AC_MSG_RESULT(no -- disabling runtime ipv6 support)
-			 ISC_PLATFORM_HAVEIN6PKTINFO="#undef ISC_PLATFORM_HAVEIN6PKTINFO"])
-		;;
-	no)
-		ISC_PLATFORM_HAVEIPV6="#undef ISC_PLATFORM_HAVEIPV6"
-		ISC_PLATFORM_NEEDIN6ADDRANY="#undef ISC_PLATFORM_NEEDIN6ADDRANY"
-		ISC_PLATFORM_HAVEIN6PKTINFO="#undef ISC_PLATFORM_HAVEIN6PKTINFO"
-		ISC_PLATFORM_HAVESCOPEID="#define ISC_PLATFORM_HAVESCOPEID 1"
-		ISC_IPV6_H="ipv6.h"
-		ISC_IPV6_O="ipv6.$O"
-		ISC_ISCIPV6_O="unix/ipv6.$O"
-		ISC_IPV6_C="ipv6.c"
-		;;
-esac
+AC_MSG_CHECKING([for in6_pktinfo])
+AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM(
+     [[
+       #include <sys/types.h>
+       #include <sys/socket.h>
+       #include <netinet/in.h>
+     ]],
+     [[
+       struct in6_pktinfo xyzzy; return (0);
+     ]])],
+  [AC_MSG_RESULT(yes)
+   ISC_PLATFORM_HAVEIN6PKTINFO="#define ISC_PLATFORM_HAVEIN6PKTINFO 1"],
+  [AC_MSG_RESULT(no -- disabling runtime ipv6 support)
+   ISC_PLATFORM_HAVEIN6PKTINFO="#undef ISC_PLATFORM_HAVEIN6PKTINFO"])
 
 AC_MSG_CHECKING(for struct sockaddr_storage)
 AC_TRY_COMPILE([
@@ -2079,16 +2083,11 @@ ISC_PLATFORM_HAVESOCKADDRSTORAGE="#define ISC_PLATFORM_HAVESOCKADDRSTORAGE 1"],
 [AC_MSG_RESULT(no)
 ISC_PLATFORM_HAVESOCKADDRSTORAGE="#undef ISC_PLATFORM_HAVESOCKADDRSTORAGE"])
 
-AC_SUBST(ISC_PLATFORM_HAVEIPV6)
 AC_SUBST(ISC_PLATFORM_HAVEINADDR6)
 AC_SUBST(ISC_PLATFORM_NEEDIN6ADDRANY)
 AC_SUBST(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)
 AC_SUBST(ISC_PLATFORM_HAVEIN6PKTINFO)
 AC_SUBST(ISC_PLATFORM_HAVESOCKADDRSTORAGE)
-AC_SUBST(ISC_IPV6_H)
-AC_SUBST(ISC_IPV6_O)
-AC_SUBST(ISC_ISCIPV6_O)
-AC_SUBST(ISC_IPV6_C)
 AC_SUBST(ISC_PLATFORM_HAVESCOPEID)
 
 AC_MSG_CHECKING([for struct if_laddrreq])
diff --git a/lib/isc/Makefile.in b/lib/isc/Makefile.in
index 010fc65b5e..d4e316865a 100644
--- a/lib/isc/Makefile.in
+++ b/lib/isc/Makefile.in
@@ -26,7 +26,7 @@ CDEFINES =
 CWARNINGS =
 
 # Alphabetically
-UNIXOBJS =	@ISC_ISCIPV6_O@ unix/pk11_api.@O@ \
+UNIXOBJS =	unix/pk11_api.@O@ \
 		unix/app.@O@ unix/dir.@O@ unix/errno.@O@ \
 		unix/errno2result.@O@ unix/file.@O@ unix/fsaccess.@O@ \
 		unix/interfaceiter.@O@ unix/keyboard.@O@ unix/meminfo.@O@ \
diff --git a/lib/isc/include/isc/ipv6.h b/lib/isc/include/isc/ipv6.h
deleted file mode 100644
index 0d69379e36..0000000000
--- a/lib/isc/include/isc/ipv6.h
+++ /dev/null
@@ -1,134 +0,0 @@
-/*
- * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- *
- * See the COPYRIGHT file distributed with this work for additional
- * information regarding copyright ownership.
- */
-
-#ifndef ISC_IPV6_H
-#define ISC_IPV6_H 1
-
-/*****
- ***** Module Info
- *****/
-
-/*! \file isc/ipv6.h
- * \brief IPv6 definitions for systems which do not support IPv6.
- *
- * \li MP:
- *	No impact.
- *
- * \li Reliability:
- *	No anticipated impact.
- *
- * \li Resources:
- *	N/A.
- *
- * \li Security:
- *	No anticipated impact.
- *
- * \li Standards:
- *	RFC2553.
- */
-
-/***
- *** Imports.
- ***/
-
-#include <inttypes.h>
-#include <isc/platform.h>
-
-/***
- *** Types.
- ***/
-
-struct in6_addr {
-	union {
-		uint8_t	_S6_u8[16];
-		uint16_t	_S6_u16[8];
-		uint32_t	_S6_u32[4];
-	} _S6_un;
-};
-#define s6_addr		_S6_un._S6_u8
-#define s6_addr8	_S6_un._S6_u8
-#define s6_addr16	_S6_un._S6_u16
-#define s6_addr32	_S6_un._S6_u32
-
-#define IN6ADDR_ANY_INIT 	{{{ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }}}
-#define IN6ADDR_LOOPBACK_INIT 	{{{ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 }}}
-
-LIBISC_EXTERNAL_DATA extern const struct in6_addr in6addr_any;
-LIBISC_EXTERNAL_DATA extern const struct in6_addr in6addr_loopback;
-
-struct sockaddr_in6 {
-#ifdef ISC_PLATFORM_HAVESALEN
-	uint8_t		sin6_len;
-	uint8_t		sin6_family;
-#else
-	uint16_t		sin6_family;
-#endif
-	uint16_t		sin6_port;
-	uint32_t		sin6_flowinfo;
-	struct in6_addr		sin6_addr;
-	uint32_t		sin6_scope_id;
-};
-
-#ifdef ISC_PLATFORM_HAVESALEN
-#define SIN6_LEN 1
-#endif
-
-/*%
- * Unspecified
- */
-#define IN6_IS_ADDR_UNSPECIFIED(a)      \
-	(((a)->s6_addr32[0] == 0) &&    \
-	 ((a)->s6_addr32[1] == 0) &&    \
-	 ((a)->s6_addr32[2] == 0) &&    \
-	 ((a)->s6_addr32[3] == 0))
-
-/*%
- * Loopback
- */
-#define IN6_IS_ADDR_LOOPBACK(a)         \
-	(((a)->s6_addr32[0] == 0) &&    \
-	 ((a)->s6_addr32[1] == 0) &&    \
-	 ((a)->s6_addr32[2] == 0) &&    \
-	 ((a)->s6_addr32[3] == htonl(1)))
-
-/*%
- * IPv4 compatible
- */
-#define IN6_IS_ADDR_V4COMPAT(a)         \
-	(((a)->s6_addr32[0] == 0) &&    \
-	 ((a)->s6_addr32[1] == 0) &&    \
-	 ((a)->s6_addr32[2] == 0) &&    \
-	 ((a)->s6_addr32[3] != 0) &&    \
-	 ((a)->s6_addr32[3] != htonl(1)))
-
-/*%
- * Mapped
- */
-#define IN6_IS_ADDR_V4MAPPED(a)               \
-	(((a)->s6_addr32[0] == 0) &&          \
-	 ((a)->s6_addr32[1] == 0) &&          \
-	 ((a)->s6_addr32[2] == htonl(0x0000ffff)))
-
-/*%
- * Multicast
- */
-#define IN6_IS_ADDR_MULTICAST(a)	\
-	((a)->s6_addr8[0] == 0xffU)
-
-/*%
- * Unicast link / site local.
- */
-#define IN6_IS_ADDR_LINKLOCAL(a)	\
-	(((a)->s6_addr[0] == 0xfe) && (((a)->s6_addr[1] & 0xc0) == 0x80))
-#define IN6_IS_ADDR_SITELOCAL(a)	\
-	(((a)->s6_addr[0] == 0xfe) && (((a)->s6_addr[1] & 0xc0) == 0xc0))
-
-#endif /* ISC_IPV6_H */
diff --git a/lib/isc/include/isc/platform.h.in b/lib/isc/include/isc/platform.h.in
index 5f10e621fe..3cc5b89e1f 100644
--- a/lib/isc/include/isc/platform.h.in
+++ b/lib/isc/include/isc/platform.h.in
@@ -36,12 +36,6 @@
  */
 @ISC_PLATFORM_HAVESALEN@
 
-/*! \brief
- * If this system has the IPv6 structure definitions, ISC_PLATFORM_HAVEIPV6
- * will be defined.
- */
-@ISC_PLATFORM_HAVEIPV6@
-
 /*! \brief
  * If this system is missing in6addr_any, ISC_PLATFORM_NEEDIN6ADDRANY will
  * be defined.
diff --git a/lib/isc/tests/socket_test.c b/lib/isc/tests/socket_test.c
index 679c47cda4..1bfe65f3a2 100644
--- a/lib/isc/tests/socket_test.c
+++ b/lib/isc/tests/socket_test.c
@@ -412,7 +412,6 @@ ATF_TC_HEAD(udp_dscp_v6, tc) {
 	atf_tc_set_md_var(tc, "descr", "udp dscp ipv6");
 }
 ATF_TC_BODY(udp_dscp_v6, tc) {
-#if defined(ISC_PLATFORM_HAVEIPV6)
 	isc_result_t result;
 	isc_sockaddr_t addr1, addr2;
 	struct in6_addr in6;
@@ -508,10 +507,6 @@ ATF_TC_BODY(udp_dscp_v6, tc) {
 	isc_socket_detach(&s2);
 
 	isc_test_end();
-#else
-	UNUSED(tc);
-	atf_tc_skip("IPv6 not available");
-#endif
 }
 
 /* Test TCP sendto/recv (IPv4) */
@@ -618,7 +613,6 @@ ATF_TC_HEAD(tcp_dscp_v6, tc) {
 	atf_tc_set_md_var(tc, "descr", "tcp dscp ipv6");
 }
 ATF_TC_BODY(tcp_dscp_v6, tc) {
-#ifdef ISC_PLATFORM_HAVEIPV6
 	isc_result_t result;
 	isc_sockaddr_t addr1;
 	struct in6_addr in6;
@@ -717,10 +711,6 @@ ATF_TC_BODY(tcp_dscp_v6, tc) {
 	isc_socket_detach(&s3);
 
 	isc_test_end();
-#else
-	UNUSED(tc);
-	atf_tc_skip("IPv6 not available");
-#endif
 }
 
 ATF_TC(net_probedscp);
diff --git a/lib/isc/unix/Makefile.in b/lib/isc/unix/Makefile.in
index c558494825..190540cdaf 100644
--- a/lib/isc/unix/Makefile.in
+++ b/lib/isc/unix/Makefile.in
@@ -21,7 +21,7 @@ CDEFINES =
 CWARNINGS =
 
 # Alphabetically
-OBJS =		@ISC_IPV6_O@ pk11_api.@O@ \
+OBJS =		pk11_api.@O@ \
 		app.@O@ dir.@O@ errno.@O@ errno2result.@O@ \
 		file.@O@ fsaccess.@O@ interfaceiter.@O@ \
 		keyboard.@O@ meminfo.@O@ \
@@ -29,7 +29,7 @@ OBJS =		@ISC_IPV6_O@ pk11_api.@O@ \
 		strerror.@O@ syslog.@O@ time.@O@
 
 # Alphabetically
-SRCS =		@ISC_IPV6_C@ pk11_api.c \
+SRCS =		pk11_api.c \
 		app.c dir.c errno.c errno2result.c \
 		file.c fsaccess.c interfaceiter.c keyboard.c meminfo.c \
 		net.c os.c resource.c socket.c stdio.c stdtime.c \
diff --git a/lib/isc/unix/ifiter_ioctl.c b/lib/isc/unix/ifiter_ioctl.c
index 08143ae25a..fcccb7946d 100644
--- a/lib/isc/unix/ifiter_ioctl.c
+++ b/lib/isc/unix/ifiter_ioctl.c
@@ -397,11 +397,7 @@ internal_current4(isc_interfaceiter_t *iter) {
 	memmove(&ifreq, ifrp, sizeof(ifreq));
 
 	family = ifreq.ifr_addr.sa_family;
-#if defined(ISC_PLATFORM_HAVEIPV6)
 	if (family != AF_INET && family != AF_INET6)
-#else
-	if (family != AF_INET)
-#endif
 		return (ISC_R_IGNORE);
 
 	memset(&iter->current, 0, sizeof(iter->current));
@@ -581,11 +577,7 @@ internal_current6(isc_interfaceiter_t *iter) {
 	memmove(&lifreq, ifrp, sizeof(lifreq));
 
 	family = lifreq.lifr_addr.ss_family;
-#ifdef ISC_PLATFORM_HAVEIPV6
 	if (family != AF_INET && family != AF_INET6)
-#else
-	if (family != AF_INET)
-#endif
 		return (ISC_R_IGNORE);
 
 	memset(&iter->current, 0, sizeof(iter->current));
diff --git a/lib/isc/unix/include/isc/net.h b/lib/isc/unix/include/isc/net.h
index 68e73a8166..e8ea2dab55 100644
--- a/lib/isc/unix/include/isc/net.h
+++ b/lib/isc/unix/include/isc/net.h
@@ -77,10 +77,6 @@
 #include <netinet/in.h>		/* Contractual promise. */
 #include <arpa/inet.h>		/* Contractual promise. */
 
-#ifndef ISC_PLATFORM_HAVEIPV6
-#include <isc/ipv6.h>		/* Contractual promise. */
-#endif
-
 #include <isc/lang.h>
 #include <isc/types.h>
 
@@ -88,7 +84,6 @@
 #define in6_addr in_addr6	/*%< Required for pre RFC2133 implementations. */
 #endif
 
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifndef IN6ADDR_ANY_INIT
 #ifdef s6_addr
 /*%
@@ -161,7 +156,6 @@
 #define IN6_IS_ADDR_LOOPBACK(x) \
 	(memcmp((x)->s6_addr, in6addr_loopback.s6_addr, 16) == 0)
 #endif
-#endif
 
 #ifndef AF_INET6
 /*% IPv6 */
@@ -218,7 +212,7 @@ struct sockaddr_storage {
 };
 #endif
 
-#if defined(ISC_PLATFORM_HAVEIPV6) && defined(ISC_PLATFORM_NEEDIN6ADDRANY)
+#if defined(ISC_PLATFORM_NEEDIN6ADDRANY)
 extern const struct in6_addr isc_net_in6addrany;
 /*%
  * Cope with a missing in6addr_any and in6addr_loopback.
@@ -226,7 +220,7 @@ extern const struct in6_addr isc_net_in6addrany;
 #define in6addr_any isc_net_in6addrany
 #endif
 
-#if defined(ISC_PLATFORM_HAVEIPV6) && defined(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)
+#if defined(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)
 extern const struct in6_addr isc_net_in6addrloop;
 #define in6addr_loopback isc_net_in6addrloop
 #endif
diff --git a/lib/isc/unix/ipv6.c b/lib/isc/unix/ipv6.c
deleted file mode 100644
index eb77377aac..0000000000
--- a/lib/isc/unix/ipv6.c
+++ /dev/null
@@ -1,20 +0,0 @@
-/*
- * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/.
- *
- * See the COPYRIGHT file distributed with this work for additional
- * information regarding copyright ownership.
- */
-
-
-/*! \file */
-
-#include <config.h>
-
-#include <isc/ipv6.h>
-
-const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
-const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
diff --git a/lib/isc/unix/net.c b/lib/isc/unix/net.c
index ed4eb05180..5529fb6351 100644
--- a/lib/isc/unix/net.c
+++ b/lib/isc/unix/net.c
@@ -93,21 +93,19 @@
 
 #endif /* HAVE_SYSCTLBYNAME */
 
-#if defined(ISC_PLATFORM_HAVEIPV6)
-# if defined(ISC_PLATFORM_NEEDIN6ADDRANY)
+#if defined(ISC_PLATFORM_NEEDIN6ADDRANY)
 const struct in6_addr isc_net_in6addrany = IN6ADDR_ANY_INIT;
-# endif
+#endif
 
-# if defined(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)
+#if defined(ISC_PLATFORM_NEEDIN6ADDRLOOPBACK)
 const struct in6_addr isc_net_in6addrloop = IN6ADDR_LOOPBACK_INIT;
-# endif
+#endif
 
 static isc_once_t 	once_ipv6only = ISC_ONCE_INIT;
 
-#  if defined(ISC_PLATFORM_HAVEIN6PKTINFO)
+#if defined(ISC_PLATFORM_HAVEIN6PKTINFO)
 static isc_once_t 	once_ipv6pktinfo = ISC_ONCE_INIT;
-#  endif
-#endif /* ISC_PLATFORM_HAVEIPV6 */
+#endif
 
 #ifndef ISC_CMSG_IP_TOS
 #ifdef __APPLE__
@@ -162,7 +160,6 @@ try_proto(int domain) {
 		}
 	}
 
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifdef ISC_PLATFORM_HAVEIN6PKTINFO
 	if (domain == PF_INET6) {
 		struct sockaddr_in6 sin6;
@@ -201,7 +198,6 @@ try_proto(int domain) {
 			}
 		}
 	}
-#endif
 #endif
 
 	(void)close(s);
@@ -212,11 +208,9 @@ try_proto(int domain) {
 static void
 initialize_action(void) {
 	ipv4_result = try_proto(PF_INET);
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifdef ISC_PLATFORM_HAVEIN6PKTINFO
 	ipv6_result = try_proto(PF_INET6);
 #endif
-#endif
 #ifdef ISC_PLATFORM_HAVESYSUNH
 	unix_result = try_proto(PF_UNIX);
 #endif
@@ -245,7 +239,6 @@ isc_net_probeunix(void) {
 	return (unix_result);
 }
 
-#ifdef ISC_PLATFORM_HAVEIPV6
 static void
 try_ipv6only(void) {
 #ifdef IPV6_V6ONLY
@@ -375,22 +368,17 @@ initialize_ipv6pktinfo(void) {
 				  try_ipv6pktinfo) == ISC_R_SUCCESS);
 }
 #endif /* ISC_PLATFORM_HAVEIN6PKTINFO */
-#endif /* ISC_PLATFORM_HAVEIPV6 */
 
 isc_result_t
 isc_net_probe_ipv6only(void) {
-#ifdef ISC_PLATFORM_HAVEIPV6
 	initialize_ipv6only();
-#endif
 	return (ipv6only_result);
 }
 
 isc_result_t
 isc_net_probe_ipv6pktinfo(void) {
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifdef ISC_PLATFORM_HAVEIN6PKTINFO
 	initialize_ipv6pktinfo();
-#endif
 #endif
 	return (ipv6pktinfo_result);
 }
@@ -672,7 +660,6 @@ try_dscp_v4(void) {
 
 static void
 try_dscp_v6(void) {
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifdef IPV6_TCLASS
 	char strbuf[ISC_STRERRORSIZE];
 	struct addrinfo hints, *res0;
@@ -726,7 +713,6 @@ try_dscp_v6(void) {
 	close(s);
 
 #endif /* IPV6_TCLASS */
-#endif /* ISC_PLATFORM_HAVEIPV6 */
 }
 
 static void
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index 734b3f4386..2fc4da95c0 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -2325,7 +2325,6 @@ set_rcvbuf(void) {
 	ISC_SOCKADDR_LEN_T len;
 
 	fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
-#if defined(ISC_PLATFORM_HAVEIPV6)
 	if (fd == -1) {
 		switch (errno) {
 		case EPROTONOSUPPORT:
@@ -2340,7 +2339,6 @@ set_rcvbuf(void) {
 			break;
 		}
 	}
-#endif
 	if (fd == -1)
 		return;
 
@@ -2673,7 +2671,6 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
 		}
 #endif /* SO_TIMESTAMP */
 
-#if defined(ISC_PLATFORM_HAVEIPV6)
 #ifdef ISC_PLATFORM_HAVEIN6PKTINFO
 #ifdef IPV6_RECVPKTINFO
 		/* RFC 3542 */
@@ -2718,7 +2715,6 @@ opensocket(isc__socketmgr_t *manager, isc__socket_t *sock,
 					 sizeof(action));
 		}
 #endif
-#endif /* ISC_PLATFORM_HAVEIPV6 */
 #endif /* defined(USE_CMSG) */
 
 #if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
diff --git a/lib/isc/win32/include/isc/platform.h.in b/lib/isc/win32/include/isc/platform.h.in
index 691ac00122..56eddd820f 100644
--- a/lib/isc/win32/include/isc/platform.h.in
+++ b/lib/isc/win32/include/isc/platform.h.in
@@ -42,7 +42,6 @@
 #define PATH_MAX _MAX_PATH
 #endif
 
-#define ISC_PLATFORM_HAVEIPV6
 #if _MSC_VER > 1200
 #define ISC_PLATFORM_HAVEIN6PKTINFO
 #endif
diff --git a/lib/isc/win32/net.c b/lib/isc/win32/net.c
index 1a6f086437..173d7bb871 100644
--- a/lib/isc/win32/net.c
+++ b/lib/isc/win32/net.c
@@ -40,7 +40,7 @@
 #define ISC_NET_PORTRANGEHIGH 65535
 #endif	/* ISC_NET_PORTRANGEHIGH */
 
-#if defined(ISC_PLATFORM_HAVEIPV6) && defined(ISC_PLATFORM_NEEDIN6ADDRANY)
+#if defined(ISC_PLATFORM_NEEDIN6ADDRANY)
 const struct in6_addr isc_net_in6addrany = IN6ADDR_ANY_INIT;
 #endif
 
@@ -90,11 +90,9 @@ static void
 initialize_action(void) {
 	InitSockets();
 	ipv4_result = try_proto(PF_INET);
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifdef ISC_PLATFORM_HAVEIN6PKTINFO
 	ipv6_result = try_proto(PF_INET6);
 #endif
-#endif
 }
 
 static void
@@ -119,7 +117,6 @@ isc_net_probeunix(void) {
 	return (ISC_R_NOTFOUND);
 }
 
-#ifdef ISC_PLATFORM_HAVEIPV6
 static void
 try_ipv6only(void) {
 #ifdef IPV6_V6ONLY
@@ -259,22 +256,17 @@ initialize_ipv6pktinfo(void) {
 				  try_ipv6pktinfo) == ISC_R_SUCCESS);
 }
 #endif /* __notyet__ */
-#endif /* ISC_PLATFORM_HAVEIPV6 */
 
 isc_result_t
 isc_net_probe_ipv6only(void) {
-#ifdef ISC_PLATFORM_HAVEIPV6
 	initialize_ipv6only();
-#endif
 	return (ipv6only_result);
 }
 
 isc_result_t
 isc_net_probe_ipv6pktinfo(void) {
 #ifdef __notyet__
-#ifdef ISC_PLATFORM_HAVEIPV6
 	initialize_ipv6pktinfo();
-#endif
 #endif /* __notyet__ */
 	return (ipv6pktinfo_result);
 }
diff --git a/lib/isc/win32/socket.c b/lib/isc/win32/socket.c
index 1209292dfb..f89d323589 100644
--- a/lib/isc/win32/socket.c
+++ b/lib/isc/win32/socket.c
@@ -188,11 +188,9 @@ enum {
  * to collect the destination address and interface so the client can
  * set them on outgoing packets.
  */
-#ifdef ISC_PLATFORM_HAVEIPV6
 #ifndef USE_CMSG
 #define USE_CMSG	1
 #endif
-#endif
 
 /*
  * We really  don't want to try and use these control messages. Win32
@@ -1754,7 +1752,6 @@ socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
 	if (type == isc_sockettype_udp) {
 
 #if defined(USE_CMSG)
-#if defined(ISC_PLATFORM_HAVEIPV6)
 #ifdef IPV6_RECVPKTINFO
 		/* 2292bis */
 		if ((pf == AF_INET6)
@@ -1786,7 +1783,6 @@ socket_create(isc_socketmgr_t *manager, int pf, isc_sockettype_t type,
 					 strbuf);
 		}
 #endif /* IPV6_RECVPKTINFO */
-#endif /* ISC_PLATFORM_HAVEIPV6 */
 #endif /* defined(USE_CMSG) */
 
 #if defined(SO_RCVBUF)