diff -up dhcp-4.3.1b1/client/dhclient.8.KrJcIv dhcp-4.3.1b1/client/dhclient.8
--- dhcp-4.3.1b1/client/dhclient.8.KrJcIv	2014-07-10 17:39:25.852763873 +0200
+++ dhcp-4.3.1b1/client/dhclient.8	2014-07-10 17:54:26.841012988 +0200
@@ -458,6 +458,9 @@ used to construct a RFC4361 style client
 in the client's messages.  This client id can be overridden by
 setting a client id in the configuration file.  Overridding the
 client id in this fashion is discouraged.
+This option is turned on by default, if you want to redefine or turn off
+sending of client id, use send dhcp-client-identifier = "better identifier"
+or send dhcp-client-identifier = "" in /etc/dhcp/dhclient.conf.
 .TP
 .BI \-I
 Use the standard DDNS scheme from RFCs 4701 & 4702.  
diff -up dhcp-4.3.1b1/client/dhclient.c.KrJcIv dhcp-4.3.1b1/client/dhclient.c
--- dhcp-4.3.1b1/client/dhclient.c.KrJcIv	2014-07-10 17:54:26.829013157 +0200
+++ dhcp-4.3.1b1/client/dhclient.c	2014-07-10 17:55:50.155835918 +0200
@@ -73,7 +73,7 @@ struct sockaddr_in sockaddr_broadcast;
 struct in_addr giaddr;
 struct data_string default_duid;
 int duid_type = 0;
-int duid_v4 = 0;
+int duid_v4 = 1;
 int std_dhcid = 0;
 
 /* ASSERT_STATE() does nothing now; it used to be
@@ -1301,7 +1301,7 @@ static void setup_ib_interface(struct in
 	}
 
 	/* No client ID specified */
-	log_fatal("dhcp-client-identifier must be specified for InfiniBand");
+	//log_fatal("dhcp-client-identifier must be specified for InfiniBand");
 }
 
 /* Individual States: