diff --git a/sql/database-create.sql b/sql/database-create.sql
index dba5d1534f0d92072d899c38525ac3ef296ad611..008a6efca9849aa6d9cb90a9f7cd3bcf37f65b40 100644
--- a/sql/database-create.sql
+++ b/sql/database-create.sql
@@ -3948,6 +3948,7 @@ CREATE TABLE `virt_lans` (
   `vname` varchar(32) NOT NULL default '',
   `vnode` varchar(32) NOT NULL default '',
   `vport` tinyint(3) NOT NULL default '0',
+  `vindex` int(11) NOT NULL default '-1',
   `ip` varchar(15) NOT NULL default '',
   `delay` float(10,2) default '0.00',
   `bandwidth` int(10) unsigned default NULL,
diff --git a/sql/database-fill.sql b/sql/database-fill.sql
index f9911409237c3c5737682414fdc6b36863769076..aa44ff16dd93dbf73c9f74e8701582a2ef9d0128 100644
--- a/sql/database-fill.sql
+++ b/sql/database-fill.sql
@@ -693,6 +693,7 @@ REPLACE INTO table_regex VALUES ('virt_agents','objecttype','int','redirect','de
 REPLACE INTO table_regex VALUES ('virt_lans','pid','text','redirect','projects:pid',0,0,NULL);
 REPLACE INTO table_regex VALUES ('virt_lans','eid','text','redirect','experiments:eid',0,0,NULL);
 REPLACE INTO table_regex VALUES ('virt_lans','vname','text','redirect','virt_nodes:vname',0,0,NULL);
+REPLACE INTO table_regex VALUES ('virt_lans','vindex','int','redirect','default:int',0,4098,NULL);
 REPLACE INTO table_regex VALUES ('virt_lans','delay','float','redirect','default:float',0,0,NULL);
 REPLACE INTO table_regex VALUES ('virt_lans','bandwidth','int','redirect','default:int',0,2147483647,NULL);
 REPLACE INTO table_regex VALUES ('virt_lans','lossrate','float','function','_checklossrate',0,1,NULL);
diff --git a/sql/updates/4/227 b/sql/updates/4/227
new file mode 100644
index 0000000000000000000000000000000000000000..40fa27786cb1873833436dadbed2037f8ea2d422
--- /dev/null
+++ b/sql/updates/4/227
@@ -0,0 +1,51 @@
+#
+# Add extenal references slots to nodes table, as for geni.
+#
+use strict;
+use libdb;
+
+sub DoUpdate($$$)
+{
+    my ($dbhandle, $dbname, $version) = @_;
+
+    if (!DBSlotExists("virt_lans", "vindex")) {
+	DBQueryFatal("alter table virt_lans add ".
+		     "vindex int(11) NOT NULL default '-1' after vport");
+    }
+    DBQueryFatal("replace into table_regex VALUES ".
+		 " ('virt_lans','vindex','int','redirect','default:int', ".
+		 "  0,4098,NULL)");
+    
+    my $query_result =
+	DBQueryFatal("select * from virt_lans order by exptidx,vname,vindex");
+
+    my $curexp = -1;
+    my $curlan = "";
+    my $curidx = 0;
+
+    while (my $rowref = $query_result->fetchrow_hashref()) {
+	my $exptidx = $rowref->{'exptidx'};
+	my $vname   = $rowref->{'vname'};
+	my $vnode   = $rowref->{'vnode'};
+	my $vport   = $rowref->{'vport'};
+	my $vindex  = $rowref->{'vindex'};
+
+	# Already done.
+	next
+	    if ($vindex != -1);
+
+	if ($exptidx != $curexp || $vname ne $curlan) {
+	    $curidx = 0;
+	}
+	DBQueryFatal("update virt_lans set vindex=$curidx ".
+		     "where exptidx='$exptidx' and vname='$vname' and ".
+		     "      vnode='$vnode' and vport='$vport'");
+
+	$curidx++;
+	$curexp = $exptidx;
+	$curlan = $vname;
+    }
+    
+    return 0;
+}
+1;
diff --git a/tbsetup/ns2ir/lanlink.tcl b/tbsetup/ns2ir/lanlink.tcl
index 648a8ae5411724dacf5957ece7d1b16ac1807d18..491f616d8b7bfcb177668265260f62cf92cbe088 100644
--- a/tbsetup/ns2ir/lanlink.tcl
+++ b/tbsetup/ns2ir/lanlink.tcl
@@ -779,6 +779,7 @@ Link instproc updatedb {DB} {
     $self instvar implemented_by
     $self instvar ofenabled
     $self instvar ofcontroller
+    set vindex 0
 
     $sim spitxml_data "virt_lan_lans" [list "vname" "failureaction"] [list $self $failureaction]
 
@@ -925,6 +926,10 @@ Link instproc updatedb {DB} {
 	    lappend values ""
 	}
 
+	lappend fields "vindex"
+	lappend values $vindex
+	set vindex [expr $vindex + 1]
+
 	$sim spitxml_data "virt_lans" $fields $values
     }
 }
@@ -964,6 +969,7 @@ Lan instproc updatedb {DB} {
     $self instvar fixed_iface
     $self instvar ofenabled
     $self instvar ofcontroller
+    set vindex 0
 
     if {$modelnet_cores > 0 || $modelnet_edges > 0} {
 	perror "Lans are not allowed when using modelnet; just duplex links."
@@ -1108,6 +1114,10 @@ Lan instproc updatedb {DB} {
 	    lappend values ""
 	}
 
+	lappend fields "vindex"
+	lappend values $vindex
+	set vindex [expr $vindex + 1]
+
 	$sim spitxml_data "virt_lans" $fields $values
 
 	foreach setting_key [array names member_settings] {