diff --git a/db/Experiment.pm.in b/db/Experiment.pm.in
index d9683da4a43297505c04f3009c86789eb74ebe31..5c6869dbb4671de36cdba12d8547a06f72333875 100755
--- a/db/Experiment.pm.in
+++ b/db/Experiment.pm.in
@@ -3636,6 +3636,7 @@ sub RemovePhysicalState($;$)
 {
     my ($self, $purge) = @_;
     require Lan;
+    require Interface;
 
     # Must be a real reference. 
     return -1
@@ -3670,6 +3671,9 @@ sub RemovePhysicalState($;$)
     }
     return -1
 	if (Lan->DestroyExperimentLans($self, $purge) != 0);
+
+    return -1
+	if (Interface::LogicalWire->DeleteLogicalWires($self) != 0);
     
     if (@pnodenames || @vnodenames) {
 	my $clause1 = join(" or ", map("node_id='$_'",  @pnodenames))
@@ -3712,6 +3716,7 @@ sub BackupPhysicalState($;$$)
 {
     my ($self, $directory, $regression) = @_;
     require Lan;
+    require Interface;
 
     # Must be a real reference. 
     return -1
@@ -3755,6 +3760,9 @@ sub BackupPhysicalState($;$$)
     return -1
 	if (Lan->BackupExperimentLans($self, $pstateDir) != 0);
 
+    return -1
+	if (Interface::LogicalWire->BackupLogicalWires($self, $pstateDir) != 0);
+
     if (@pnodenames || @vnodenames) {
 	my $clause = join(" or ", map("node_id='$_'",
 				      (@pnodenames, @vnodenames)));
@@ -3823,6 +3831,7 @@ sub RestorePhysicalState($)
 {
     my ($self) = @_;
     require Lan;
+    require Interface;
 
     # Must be a real reference. 
     return -1
@@ -3837,6 +3846,9 @@ sub RestorePhysicalState($)
     return -1
 	if (Lan->RestoreExperimentLans($self, $pstateDir) != 0);
     
+    return -1
+	if (Interface::LogicalWire->RestoreLogicalWires($self, $pstateDir));
+    
     foreach my $table (keys(%physicalTables),
 		       "vinterfaces", "interface_settings") {
 	if (-e "$pstateDir/$table") {
diff --git a/db/Interface.pm.in b/db/Interface.pm.in
index f74689b6fd873de20a0f0212760b4fe58e24635f..1a2bcbc52eaa509f23d9102ba28c2ce5709d7327 100755
--- a/db/Interface.pm.in
+++ b/db/Interface.pm.in
@@ -1,6 +1,6 @@
 #!/usr/bin/perl -wT
 #
-# Copyright (c) 2005-2017 University of Utah and the Flux Group.
+# Copyright (c) 2005-2018 University of Utah and the Flux Group.
 # 
 # {{{EMULAB-LICENSE
 # 
@@ -2101,6 +2101,50 @@ sub DeleteLogicalWires($$)
     return $errors;
 }
 
+#
+# Backup all logical wires for an experiment, as for modify.
+#
+sub BackupLogicalWires($$$)
+{
+    my ($class, $experiment, $pstatedir) = @_;
+    my $exptidx = $experiment->idx();
+
+    my $query_result =
+	DBQueryWarn("select distinct node_id1,iface1,node_id2,iface2 ".
+		    "  from logical_wires as w ".
+		    "left join reserved as r on ".
+		    "     w.node_id1=r.node_id or w.node_id2=r.node_id ".
+		    "where r.exptidx='$exptidx'");
+    return -1
+	if (!$query_result);
+    return 0
+	if (!$query_result->numrows);
+
+    DBQueryWarn("select distinct w.* from logical_wires as w ".
+		"left join reserved as r on ".
+		"     w.node_id1=r.node_id or w.node_id2=r.node_id ".
+		"where r.exptidx='$exptidx' ".
+		"into outfile '$pstatedir/logical_wires'")
+	or return -1;
+
+    return 0
+}
+
+#
+# Restore all logical wires for an experiment, as for modify.
+#
+sub RestoreLogicalWires($$$)
+{
+    my ($class, $experiment, $pstatedir) = @_;
+
+    if (-e "$pstatedir/logical_wires") {
+	DBQueryWarn("load data infile '$pstatedir/logical_wires' ".
+		    "replace into table logical_wires")
+	    or return -1;
+    }
+    return 0;
+}
+
 ##############################################################################
 #
 # A trivial wrapper class for interface_types.
diff --git a/protogeni/lib/GeniCM.pm.in b/protogeni/lib/GeniCM.pm.in
index 029c681461f90b7b03e4cc2668e56e96290acee0..4aff142f77e614e6f9380016cbddde8378f13b43 100755
--- a/protogeni/lib/GeniCM.pm.in
+++ b/protogeni/lib/GeniCM.pm.in
@@ -7127,6 +7127,10 @@ sub CleanupDeadSlice($;$)
 		return -1;
 	    }
 	}
+	if (Interface::LogicalWire->DeleteLogicalWires($experiment)) {
+	    print STDERR "Could not delete logical wires and interfaces\n";
+	    return -1;
+	}
 
 	#
 	# A firewalled slice gets special treatment.