diff --git a/internal/handlers/connections.go b/internal/handlers/connections.go
index 2bd87c6..215a266 100644
--- a/internal/handlers/connections.go
+++ b/internal/handlers/connections.go
@@ -11,71 +11,7 @@ import (
 
 func (h *Handlers) ConnectionModal(w http.ResponseWriter, r *http.Request) {
 	portIDStr := r.PathValue("portId")
-	portID, err := strconv.ParseInt(portIDStr, 10, 64)
-	if err != nil {
-		http.Error(w, "invalid port id", http.StatusBadRequest)
-		return
-	}
-
-	trace, err := services.TraceConnection(h.Store, portID)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-		return
-	}
-
-	connTypes, _ := h.Store.ConnectionTypeGetAll()
-	if connTypes == nil {
-		connTypes = []models.ConnectionType{}
-	}
-
-	type ConnectionModalData struct {
-		Trace           *services.TraceResult
-		ConnectionTypes []models.ConnectionType
-		AllPorts        []FlatPort
-		Error           string
-	}
-
-	allDevices, _ := h.Store.DeviceGetAllUnracked()
-	rackedDevicesMap := map[int64]bool{}
-
-	var flatPorts []FlatPort
-	addDevicePorts := func(devices []models.Device) {
-		for _, d := range devices {
-			if rackedDevicesMap[d.ID] {
-				continue
-			}
-			rackedDevicesMap[d.ID] = true
-			for _, p := range d.Ports {
-				flatPorts = append(flatPorts, FlatPort{
-					ID:          p.ID,
-					Name:        p.Name,
-					Side:        p.Side,
-					DeviceID:    d.ID,
-					DeviceName:  d.Name,
-					DeviceModel: "",
-				})
-				if d.Model != nil {
-					flatPorts[len(flatPorts)-1].DeviceModel = d.Model.Name
-				}
-			}
-		}
-	}
-
-	addDevicePorts(allDevices)
-	for _, rack := range h.mustGetAllRacks() {
-		if devs, err := h.Store.DeviceGetByRackID(rack.ID); err == nil {
-			addDevicePorts(devs)
-		}
-		if devs, err := h.Store.DeviceGetUnrackedByRackID(rack.ID); err == nil {
-			addDevicePorts(devs)
-		}
-	}
-
-	h.render(w, "connection_modal.html", ConnectionModalData{
-		Trace:           trace,
-		ConnectionTypes: connTypes,
-		AllPorts:        flatPorts,
-	})
+	h.renderConnectionModal(w, portIDStr)
 }
 
 type FlatPort struct {
@@ -95,6 +31,67 @@ func (h *Handlers) mustGetAllRacks() []models.Rack {
 	return racks
 }
 
+func (h *Handlers) ConnectionDelete(w http.ResponseWriter, r *http.Request) {
+	idStr := r.PathValue("id")
+	id, _ := strconv.ParseInt(idStr, 10, 64)
+	returnPortID := r.URL.Query().Get("return_port_id")
+
+	h.Store.ConnectionDelete(id)
+
+	if returnPortID != "" {
+		h.renderConnectionModal(w, returnPortID)
+		return
+	}
+	h.redirect(w, r, "/")
+}
+
+func (h *Handlers) ConnectionEdit(w http.ResponseWriter, r *http.Request) {
+	idStr := r.PathValue("id")
+	id, _ := strconv.ParseInt(idStr, 10, 64)
+	r.ParseForm()
+
+	_, err := h.Store.ConnectionGetByID(id)
+	if err != nil {
+		http.Error(w, "connection not found", http.StatusNotFound)
+		return
+	}
+
+	connTypeID, _ := strconv.ParseInt(r.FormValue("connection_type_id"), 10, 64)
+	label1 := r.FormValue("label_1")
+	label2 := r.FormValue("label_2")
+	color := r.FormValue("color")
+	returnPortID := r.FormValue("return_port_id")
+
+	if color == "" {
+		color = "#808080"
+	}
+
+	var label1Ptr, label2Ptr *string
+	if label1 != "" {
+		label1Ptr = &label1
+	}
+	if label2 != "" {
+		label2Ptr = &label2
+	}
+
+	_, err = h.Store.ConnectionGetByID(id)
+	if err == nil {
+		_ = h.Store.ConnectionUpdate(&models.Connection{
+			ID:               id,
+			ConnectionTypeID: connTypeID,
+			Label1:           label1Ptr,
+			Label2:           label2Ptr,
+			Color:            color,
+		})
+	}
+
+	if returnPortID != "" {
+		h.renderConnectionModal(w, returnPortID)
+		return
+	}
+	h.redirect(w, r, "/")
+}
+
 func (h *Handlers) ConnectionCreate(w http.ResponseWriter, r *http.Request) {
 	r.ParseForm()
 
@@ -138,79 +135,85 @@ func (h *Handlers) ConnectionCreate(w http.ResponseWriter, r *http.Request) {
 	}
 
 	if err := h.Store.ConnectionCreate(conn); err != nil {
-		h.redirect(w, r, "/connections/"+returnPortID)
+		if returnPortID != "" {
+			h.renderConnectionModal(w, returnPortID)
+			return
+		}
+		h.redirect(w, r, "/")
 		return
 	}
 
 	if returnPortID != "" {
-		h.redirect(w, r, "/connections/"+returnPortID)
+		h.renderConnectionModal(w, returnPortID)
 		return
 	}
 	h.redirect(w, r, "/")
 }
 
-func (h *Handlers) ConnectionEdit(w http.ResponseWriter, r *http.Request) {
-	idStr := r.PathValue("id")
-	id, _ := strconv.ParseInt(idStr, 10, 64)
-	r.ParseForm()
-
-	conn, err := h.Store.ConnectionGetByID(id)
-	if err != nil || conn == nil {
-		http.Error(w, "connection not found", http.StatusNotFound)
+func (h *Handlers) renderConnectionModal(w http.ResponseWriter, returnPortID string) {
+	portID, err := strconv.ParseInt(returnPortID, 10, 64)
+	if err != nil {
+		http.Error(w, "invalid port id", http.StatusBadRequest)
 		return
 	}
 
-	connTypeID, _ := strconv.ParseInt(r.FormValue("connection_type_id"), 10, 64)
-	label1 := r.FormValue("label_1")
-	label2 := r.FormValue("label_2")
-	color := r.FormValue("color")
-	returnPortID := r.FormValue("return_port_id")
-
-	if color == "" {
-		color = "#808080"
-	}
-
-	conn.ConnectionTypeID = connTypeID
-	if label1 != "" {
-		conn.Label1 = &label1
-	} else {
-		conn.Label1 = nil
-	}
-	if label2 != "" {
-		conn.Label2 = &label2
-	} else {
-		conn.Label2 = nil
-	}
-	conn.Color = color
-
-	if err := h.Store.ConnectionUpdate(conn); err != nil {
-		if returnPortID != "" {
-			h.redirect(w, r, "/connections/"+returnPortID)
-			return
-		}
+	trace, err := services.TraceConnection(h.Store, portID)
+	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
-	if returnPortID != "" {
-		h.redirect(w, r, "/connections/"+returnPortID)
-		return
+	connTypes, _ := h.Store.ConnectionTypeGetAll()
+	if connTypes == nil {
+		connTypes = []models.ConnectionType{}
 	}
-	h.redirect(w, r, "/")
-}
 
-func (h *Handlers) ConnectionDelete(w http.ResponseWriter, r *http.Request) {
-	idStr := r.PathValue("id")
-	id, _ := strconv.ParseInt(idStr, 10, 64)
-	returnPortID := r.URL.Query().Get("return_port_id")
-
-	h.Store.ConnectionDelete(id)
-
-	if returnPortID != "" {
-		h.redirect(w, r, "/connections/"+returnPortID)
-		return
+	type ConnectionModalData struct {
+		Trace           *services.TraceResult
+		ConnectionTypes []models.ConnectionType
+		AllPorts        []FlatPort
 	}
-	h.redirect(w, r, "/")
+
+	allDevices, _ := h.Store.DeviceGetAllUnracked()
+	visitedMap := map[int64]bool{}
+
+	var flatPorts []FlatPort
+	addPorts := func(devices []models.Device) {
+		for _, d := range devices {
+			if visitedMap[d.ID] {
+				continue
+			}
+			visitedMap[d.ID] = true
+			for _, p := range d.Ports {
+				flatPorts = append(flatPorts, FlatPort{
+					ID:         p.ID,
+					Name:       p.Name,
+					Side:       p.Side,
+					DeviceID:   d.ID,
+					DeviceName: d.Name,
+				})
+				if d.Model != nil {
+					flatPorts[len(flatPorts)-1].DeviceModel = d.Model.Name
+				}
+			}
+		}
+	}
+
+	addPorts(allDevices)
+	for _, rack := range h.mustGetAllRacks() {
+		if devs, err := h.Store.DeviceGetByRackID(rack.ID); err == nil {
+			addPorts(devs)
+		}
+		if devs, err := h.Store.DeviceGetUnrackedByRackID(rack.ID); err == nil {
+			addPorts(devs)
+		}
+	}
+
+	h.render(w, "connection_modal.html", ConnectionModalData{
+		Trace:           trace,
+		ConnectionTypes: connTypes,
+		AllPorts:        flatPorts,
+	})
 }
 
 func (h *Handlers) ConnectionGetByID(id int64) (*models.Connection, error) {
diff --git a/internal/handlers/racks.go b/internal/handlers/racks.go
index 8a633c1..ce25fe0 100644
--- a/internal/handlers/racks.go
+++ b/internal/handlers/racks.go
@@ -82,8 +82,8 @@ func buildRackSlots(heightUnits int, devices []models.Device) (front, back []Rac
 	front = make([]RackSlot, heightUnits)
 	back = make([]RackSlot, heightUnits)
 	for i := range front {
-		front[i].Unit = i + 1
-		back[i].Unit = i + 1
+		front[i].Unit = heightUnits - i
+		back[i].Unit = heightUnits - i
 	}
 
 	for _, d := range devices {
@@ -94,7 +94,7 @@ func buildRackSlots(heightUnits int, devices []models.Device) (front, back []Rac
 		if d.Model != nil && d.Model.HeightUnits != nil {
 			height = *d.Model.HeightUnits
 		}
-		start := *d.RackUnitStart - 1
+		start := heightUnits - *d.RackUnitStart
 		if start < 0 || start >= heightUnits {
 			continue
 		}
diff --git a/lostcavewireplanner b/lostcavewireplanner
new file mode 100755
index 0000000..3d22a12
Binary files /dev/null and b/lostcavewireplanner differ