diff --git a/main.go b/main.go
index 2d0e722..9ea6f6e 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,7 @@ package main
  * https://github.com/joeig/go-powerdns
  * https://github.com/xlzd/gotp
  * https://github.com/dspinhirne/netaddr-go => https://pkg.go.dev/github.com/dspinhirne/netaddr-go
- * https://github.com/go-yaml/yaml/tree/v2.4.0 => 
+ * https://github.com/go-yaml/yaml/tree/v2.4.0 =>
  */
 import (
 	"context"
@@ -40,6 +40,14 @@ func (c *conf) getConf() *conf {
 }
 
 func main() {
+    f, err := os.OpenFile("/tmp/testlogfile", os.O_RDWR | os.O_CREATE | os.O_APPEND, 0666)
+    if err != nil {
+        log.Fatalf("error opening file: %v", err)
+    }
+    defer f.Close()
+
+    log.SetOutput(f)
+
 	var c conf
 	c.getConf()
 
@@ -57,7 +65,8 @@ func main() {
 			if userIP == nil {
 				log.Fatalf("Err %v ", err)
 			}
-			fmt.Fprintf(w, "IP: %q \n", ip)
+			//fmt.Fprintf(w, "IP: %q \n", ip)
+			//fmt.Fprintf(w, "IP: %q \n", ip)
 			log.Println(fmt.Sprintf("TOTP : %q", gotp.NewDefaultTOTP(c.TotpToken).Now()))
 			log.Println(fmt.Sprintf("Token: %q", token))
 
@@ -80,16 +89,33 @@ func main() {
 						new_ipv6 := netaddr.NewIPv6(new_prefix, hostId)
 						log.Println(fmt.Sprintf("Host: %q -> %q needs update: %t", ipv6, new_ipv6, ipv6.Long() != new_ipv6.Long()))
 						if ipv6.Long() != new_ipv6.Long() {
+							fmt.Fprintf(w, "Update Host %q to %q\n", *r.Name, ip)
 							updated = true
 							err = pdns.Records.Change(ctx, c.Zone, record_to_update+"."+c.Zone, powerdns.RRTypeAAAA, 30, []string{new_ipv6.Long()})
 							if err != nil {
-								log.Fatalf("Update err %v ", err)
+                                log.Fatalf("Update err %v ", err)
 							}
+						} else {
+							fmt.Fprintf(w, "No update for host %q\n", *r.Name)
 						}
 					}
 				}
 			}
 			if updated {
+				// increase serial
+				zone, err := pdns.Zones.Get(ctx, c.Zone)
+				if err != nil {
+					log.Fatalf("%v", err)
+				}
+				serial := *zone.Serial
+				zoneChangeSet := &powerdns.Zone{
+					Serial: powerdns.Uint32(serial + 1),
+				}
+
+				if err := pdns.Zones.Change(ctx, c.Zone, zoneChangeSet); err != nil {
+					log.Fatalf("%v", err)
+				}
+
 				pdns.Zones.Notify(ctx, c.Zone)
 				log.Println("Updated...")
 			}