Apply by doing:
        cd /usr/src/sbin/isakmpd
        patch -p0 < 017_isakmpd.patch

Rebuild and install isakmpd:
        make cleandir
        make obj
        make depend
        make && make install

Restart isakmpd:
        kill `cat /var/run/isakmpd.pid`
	/sbin/isakmpd

Index: message.c
===================================================================
RCS file: /cvs/src/sbin/isakmpd/message.c,v
retrieving revision 1.45
diff -u -u -r1.45 message.c
--- message.c	1 Jul 2001 20:43:39 -0000	1.45
+++ message.c	26 Mar 2002 17:54:43 -0000
@@ -880,9 +880,6 @@
   struct proto tmp_proto;
   struct sa tmp_sa;
 
-  /* Possibly dump a raw hex image of the message to the log channel.  */
-  message_dump_raw ("message_recv", msg, LOG_MESSAGE);
-
   /* Messages shorter than an ISAKMP header are bad.  */
   if (sz < ISAKMP_HDR_SZ || sz != GET_ISAKMP_HDR_LENGTH (buf))
     {
@@ -890,6 +887,11 @@
       message_drop (msg, ISAKMP_NOTIFY_UNEQUAL_PAYLOAD_LENGTHS, 0, 1, 1);
       return -1;
     }
+
+#ifdef USE_DEBUG
+  /* Possibly dump a raw hex image of the message to the log channel.  */
+  message_dump_raw ("message_recv", msg, LOG_MESSAGE);
+#endif
 
   /*
    * If the responder cookie is zero, this is a request to setup an ISAKMP SA.