diff -Naur ./common/conflex.c ../dhcp-4.2.5/common/conflex.c

--- ./common/conflex.c	2016-02-11 13:03:38.892135723 +0100

+++ ../dhcp-4.2.5/common/conflex.c	2016-02-11 13:05:18.447135723 +0100

@@ -1067,6 +1067,8 @@

 			return IF;

 		if (!strcasecmp (atom + 1, "s"))

 			return IS;

+		if (!strcasecmp (atom + 1, "gnore-client-uids"))

+			return IGNORE_CLIENT_UIDS;

 		if (!strcasecmp (atom + 1, "gnore"))

 			return IGNORE;

 		break;

diff -Naur ./includes/dhcpd.h ../dhcp-4.2.5/includes/dhcpd.h

--- ./includes/dhcpd.h	2016-02-11 13:03:38.903135723 +0100

+++ ../dhcp-4.2.5/includes/dhcpd.h	2016-02-11 13:12:20.398135723 +0100

@@ -766,6 +766,8 @@

 #endif

 #endif

+#define SV_IGNORE_CLIENT_UIDS 78

+

 #if !defined (DEFAULT_DEFAULT_LEASE_TIME)

 # define DEFAULT_DEFAULT_LEASE_TIME 43200

 #endif

diff -Naur ./includes/dhctoken.h ../dhcp-4.2.5/includes/dhctoken.h

--- ./includes/dhctoken.h	2016-02-11 13:03:38.901135723 +0100

+++ ../dhcp-4.2.5/includes/dhctoken.h	2016-02-11 13:13:09.958135723 +0100

@@ -366,7 +366,8 @@

 	SECONDARY6 = 667,

 	TOKEN_INFINIBAND = 668,

 	BOOTP_BROADCAST_ALWAYS = 669,

-	DESTINATION_DESCRIPTOR = 670

+	DESTINATION_DESCRIPTOR = 670,

+	IGNORE_CLIENT_UIDS = 671

 };

 #define is_identifier(x)	((x) >= FIRST_TOKEN &&	\

diff -Naur ./server/confpars.c ../dhcp-4.2.5/server/confpars.c

--- ./server/confpars.c	2016-02-11 13:03:38.915135723 +0100

+++ ../dhcp-4.2.5/server/confpars.c	2016-02-11 13:15:48.269135723 +0100

@@ -332,6 +332,7 @@

 	       | ONE_LEASE_PER_CLIENT boolean

 	       | GET_LEASE_HOSTNAMES boolean

 	       | USE_HOST_DECL_NAME boolean

+	       | IGNORE_CLIENT_UIDS boolean

 	       | NEXT_SERVER ip-addr-or-hostname SEMI

 	       | option_parameter

 	       | SERVER-IDENTIFIER ip-addr-or-hostname SEMI

@@ -4125,6 +4126,10 @@

 		code = SV_LEASEQUERY;

 		break;

+	      case IGNORE_CLIENT_UIDS:

+		code = SV_IGNORE_CLIENT_UIDS;

+		break;

+

 	      default:

 		parse_warn (cfile, "expecting allow/deny key");

 		skip_to_semi (cfile);

@@ -4138,7 +4143,6 @@

 	status = option_cache(oc, NULL, data, option, MDL);

 	expression_dereference (&data, MDL);

 	parse_semi (cfile);

-	return status;

 }

 void

diff -Naur ./server/dhcp.c ../dhcp-4.2.5/server/dhcp.c

--- ./server/dhcp.c	2016-02-11 13:03:38.916135723 +0100

+++ ../dhcp-4.2.5/server/dhcp.c	2016-02-11 13:24:06.173135723 +0100

@@ -2393,34 +2393,39 @@

 	/* Update Client Last Transaction Time. */

 	lt->cltt = cur_time;

-	/* Record the uid, if given... */

-	oc = lookup_option (&dhcp_universe, packet -> options,

-			    DHO_DHCP_CLIENT_IDENTIFIER);

-	if (!oc)

+	/* See if we want to record the uid for this client */

+	oc = lookup_option(&server_universe, state->options,

+		SV_IGNORE_CLIENT_UIDS);

+	if ((oc == NULL) ||

+		!evaluate_boolean_option_cache(&ignorep, packet, lease, NULL,

+			packet->options, state->options,

+			&lease->scope, oc, MDL)) {

+

+		/* Record the uid, if given... */

 		oc = lookup_option (&dhcp_universe, packet -> options,

-				    DHO_PXE_CLIENT_ID);

-	if (oc &&

-	    evaluate_option_cache (&d1, packet, lease,

-				   (struct client_state *)0,

-				   packet -> options, state -> options,

-				   &lease -> scope, oc, MDL)) {

-		if (d1.len <= sizeof lt -> uid_buf) {

-			memcpy (lt -> uid_buf, d1.data, d1.len);

-			lt -> uid = lt -> uid_buf;

-			lt -> uid_max = sizeof lt -> uid_buf;

-			lt -> uid_len = d1.len;

-		} else {

-			unsigned char *tuid;

-			lt -> uid_max = d1.len;

-			lt -> uid_len = d1.len;

-			tuid = (unsigned char *)dmalloc (lt -> uid_max, MDL);

-			/* XXX inelegant */

-			if (!tuid)

-				log_fatal ("no memory for large uid.");

-			memcpy (tuid, d1.data, lt -> uid_len);

-			lt -> uid = tuid;

+			DHO_DHCP_CLIENT_IDENTIFIER);

+		if (oc &&

+		    evaluate_option_cache(&d1, packet, lease, NULL,

+					packet->options, state->options,

+					&lease->scope, oc, MDL)) {

+			if (d1.len <= sizeof(lt->uid_buf)) {

+				memcpy(lt->uid_buf, d1.data, d1.len);

+				lt->uid = lt->uid_buf;

+				lt->uid_max = sizeof(lt->uid_buf);

+				lt->uid_len = d1.len;

+			} else {

+				unsigned char *tuid;

+				lt->uid_max = d1.len;

+				lt->uid_len = d1.len;

+				tuid = (unsigned char *)dmalloc(lt->uid_max, MDL);

+				/* XXX inelegant */

+				if (!tuid)

+					log_fatal ("no memory for large uid.");

+				memcpy(tuid, d1.data, lt->uid_len);

+				lt->uid = tuid;

+			}

+			data_string_forget (&d1, MDL);

 		}

-		data_string_forget (&d1, MDL);

 	}

 	if (host) {

diff -Naur ./server/stables.c ../dhcp-4.2.5/server/stables.c

--- ./server/stables.c	2016-02-11 13:03:38.909135723 +0100

+++ ../dhcp-4.2.5/server/stables.c	2016-02-11 13:25:00.081135723 +0100

@@ -266,6 +266,7 @@

 	{ "ldap-tls-randfile", "t",		&server_universe,  77, 1 },

 #endif /* LDAP_USE_SSL */

 #endif /* LDAP_CONFIGURATION */

+	{ "ignore-client-uids", "f", &server_universe, 78, 1 },

 	{ NULL, NULL, NULL, 0, 0 }

 };