diff --git a/cmd/dhcp4d/dhcp4d.go b/cmd/dhcp4d/dhcp4d.go
index 1a11c24..e445f4f 100644
--- a/cmd/dhcp4d/dhcp4d.go
+++ b/cmd/dhcp4d/dhcp4d.go
@@ -435,13 +435,17 @@ func newSrv(permDir string) (*srv, error) {
 
 		// Publish the DHCP lease as JSON to MQTT, if configured:
 		leaseVal := struct {
-			Addr         string    `json:"addr"`
-			HardwareAddr string    `json:"hardware_addr"`
-			Expiration   time.Time `json:"expiration"`
+			Addr             string    `json:"addr"`
+			HardwareAddr     string    `json:"hardware_addr"`
+			Expiration       time.Time `json:"expiration"`
+			Start            time.Time `json:"start"`
+			VendorIdentifier string    `json:"vendor_identifier"`
 		}{
-			Addr:         latest.Addr.String(),
-			HardwareAddr: latest.HardwareAddr,
-			Expiration:   latest.Expiry.In(time.UTC),
+			Addr:             latest.Addr.String(),
+			HardwareAddr:     latest.HardwareAddr,
+			Expiration:       latest.Expiry.In(time.UTC),
+			Start:            latest.Start.In(time.UTC),
+			VendorIdentifier: latest.VendorIdentifier,
 		}
 		leaseJSON, err := json.Marshal(leaseVal)
 		if err != nil {
diff --git a/cmd/dhcp4d/mayqtt.go b/cmd/dhcp4d/mayqtt.go
index 725f38a..18fc404 100644
--- a/cmd/dhcp4d/mayqtt.go
+++ b/cmd/dhcp4d/mayqtt.go
@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"io/ioutil"
+	"path"
 	"strings"
 
 	mqtt "github.com/eclipse/paho.mqtt.golang"
@@ -16,7 +17,7 @@ type PublishRequest struct {
 }
 
 func publisherLoop(requests <-chan PublishRequest) error {
-	const configFn = "/perm/dhcp4d/mqtt-broker.txt"
+	configFn := path.Join(*perm, "/dhcp4d/mqtt-broker.txt")
 	b, err := ioutil.ReadFile(configFn)
 	if err != nil {
 		// discard requests:
@@ -24,11 +25,26 @@ func publisherLoop(requests <-chan PublishRequest) error {
 		}
 		return nil
 	}
+	var (
+		broker   string
+		username string
+		password string
+	)
+	cfg := strings.Split(string(b), "\n")
+
 	// e.g. tcp://10.0.0.54:1883, which is a static DHCP lease for the dr.lan
 	// Raspberry Pi, which is running an MQTT broker in my network.
-	broker := strings.TrimSpace(string(b))
+	broker = strings.TrimSpace(cfg[0])
+	if len(cfg) > 1 {
+		username = cfg[1]
+	}
+	if len(cfg) > 2 {
+		password = cfg[2]
+	}
 	log.Printf("Connecting to MQTT broker %q (configured in %s)", broker, configFn)
 	opts := mqtt.NewClientOptions().AddBroker(broker)
+	opts.SetUsername(username)
+	opts.SetPassword(password)
 	opts.SetClientID("dhcp4d")
 	opts.SetConnectRetry(true)
 	mqttClient := mqtt.NewClient(opts)
diff --git a/internal/dhcp4d/dhcp4d.go b/internal/dhcp4d/dhcp4d.go
index 01f5e0b..eed7acd 100644
--- a/internal/dhcp4d/dhcp4d.go
+++ b/internal/dhcp4d/dhcp4d.go
@@ -345,7 +345,7 @@ func (h *Handler) serveDHCP(p dhcp4.Packet, msgType dhcp4.MessageType, options d
 			Expiry:           now.Add(h.leasePeriodForDevice(hwAddr)),
 			Hostname:         string(options[dhcp4.OptionHostName]),
 			Start:            now,
-			VendorIdentifier: string(options[dhcp4.OptionVendorClassIdentifier]),
+			VendorIdentifier: string(bytes.ToValidUTF8(bytes.ReplaceAll(options[dhcp4.OptionVendorClassIdentifier], []byte{0}, []byte{}), []byte{})),
 		}
 		copy(lease.Addr, reqIP.To4())