diff --git a/CHANGES b/CHANGES
index 57affeee7d..d49b90eb43 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+1283.	[func]		Use "dataready" accept filter if available.
+
 1281.	[func]		Log zone when unable to get private keys to update
 			zone.  Log zone when NXT records are missing from
 			secure zone.
diff --git a/bin/named/interfacemgr.c b/bin/named/interfacemgr.c
index d4bdaa628e..c859742fab 100644
--- a/bin/named/interfacemgr.c
+++ b/bin/named/interfacemgr.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: interfacemgr.c,v 1.59.2.5.8.2 2003/08/08 07:12:25 marka Exp $ */
+/* $Id: interfacemgr.c,v 1.59.2.5.8.3 2003/08/15 01:16:05 marka Exp $ */
 
 #include <config.h>
 
@@ -312,6 +312,12 @@ ns_interface_accepttcp(ns_interface_t *ifp) {
 		goto tcp_listen_failure;
 	}
 
+	/* 
+	 * If/when there a multiple filters listen to the
+	 * result.
+	 */
+	(void)isc_socket_filter(ifp->tcpsocket, "dataready");
+
 	result = ns_clientmgr_createclients(ifp->clientmgr,
 					    ifp->ntcptarget, ifp,
 					    ISC_TRUE);
diff --git a/lib/isc/include/isc/msgs.h b/lib/isc/include/isc/msgs.h
index 43ed4d354f..87033ec5f4 100644
--- a/lib/isc/include/isc/msgs.h
+++ b/lib/isc/include/isc/msgs.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: msgs.h,v 1.5.2.2 2002/08/05 06:57:15 marka Exp $ */
+/* $Id: msgs.h,v 1.5.2.2.8.1 2003/08/15 01:16:06 marka Exp $ */
 
 #ifndef ISC_MSGS_H
 #define ISC_MSGS_H 1
@@ -145,6 +145,7 @@
 #define ISC_MSG_ACCEPTRETURNED 1418 /* accept() returned %d/%s */
 #define ISC_MSG_TOOMANYFDS     1419 /* %s: too many open file descriptors */
 #define ISC_MSG_ZEROPORT       1420 /* dropping source port zero packet */
+#define ISC_MSG_FILTER	       1420 /* setsockopt(SO_ACCEPTFILTER): %s */
 
 #define ISC_MSG_AWAKE	       1502 /* "awake" */
 #define ISC_MSG_WORKING	       1503 /* "working" */
diff --git a/lib/isc/include/isc/socket.h b/lib/isc/include/isc/socket.h
index ea4099164f..fba12670d5 100644
--- a/lib/isc/include/isc/socket.h
+++ b/lib/isc/include/isc/socket.h
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.h,v 1.54.12.1 2003/08/08 06:50:17 marka Exp $ */
+/* $Id: socket.h,v 1.54.12.2 2003/08/15 01:16:06 marka Exp $ */
 
 #ifndef ISC_SOCKET_H
 #define ISC_SOCKET_H 1
@@ -326,6 +326,13 @@ isc_socket_bind(isc_socket_t *sock, isc_sockaddr_t *addressp);
  *	ISC_R_UNEXPECTED
  */
 
+isc_result_t
+isc_socket_filter(isc_socket_t *sock, const char *filter);
+/*
+ * Inform the kernel that it should perform accept filtering.
+ * If filter is NULL the current filter will be removed.:w
+ */
+
 isc_result_t
 isc_socket_listen(isc_socket_t *sock, unsigned int backlog);
 /*
diff --git a/lib/isc/unix/socket.c b/lib/isc/unix/socket.c
index 06d451ff4d..62d472f55c 100644
--- a/lib/isc/unix/socket.c
+++ b/lib/isc/unix/socket.c
@@ -15,7 +15,7 @@
  * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id: socket.c,v 1.207.2.19.2.2 2003/08/14 04:31:55 marka Exp $ */
+/* $Id: socket.c,v 1.207.2.19.2.3 2003/08/15 01:16:06 marka Exp $ */
 
 #include <config.h>
 
@@ -2831,6 +2831,35 @@ isc_socket_bind(isc_socket_t *sock, isc_sockaddr_t *sockaddr) {
 	return (ISC_R_SUCCESS);
 }
 
+isc_result_t
+isc_socket_filter(isc_socket_t *sock, const char *filter) {
+#ifdef SO_ACCEPTFILTER
+	char strbuf[ISC_STRERRORSIZE];
+	struct accept_filter_arg afa;
+#else
+	UNUSED(sock);
+	UNUSED(filter);
+#endif
+
+	REQUIRE(VALID_SOCKET(sock));
+
+#ifdef SO_ACCEPTFILTER
+	bzero(&afa, sizeof(afa));
+	strncpy(afa.af_name, filter, sizeof(afa.af_name));
+	if (setsockopt(sock->fd, SOL_SOCKET, SO_ACCEPTFILTER,
+			 &afa, sizeof(afa)) == -1) {
+		isc__strerror(errno, strbuf, sizeof(strbuf));
+		socket_log(sock, NULL, CREATION, isc_msgcat, ISC_MSGSET_SOCKET,
+			   ISC_MSG_FILTER, "setsockopt(SO_ACCEPTFILTER): %s",
+			   strbuf);
+		return (ISC_R_FAILURE);
+	}
+	return (ISC_R_SUCCESS);
+#else
+	return (ISC_R_NOTIMPLEMENTED);
+#endif
+}
+
 /*
  * Set up to listen on a given socket.  We do this by creating an internal
  * event that will be dispatched when the socket has read activity.  The