diff --git a/ldap.go b/ldap.go
index e5e3ba7..0eefe8b 100644
--- a/ldap.go
+++ b/ldap.go
@@ -3,15 +3,36 @@ package main
 import (
 	"crypto/tls"
 	"fmt"
+	"strconv"
 	"strings"
 
 	"github.com/go-ldap/ldap/v3"
 )
 
 func fetchDataFromLDAP() ([]Person, error) {
-	l, err := ldap.DialTLS("tcp", ldapConfig.Server+":"+ldapConfig.Port, &tls.Config{InsecureSkipVerify: true})
+	var l *ldap.Conn
+	var err error
+
+	// Port überprüfen und entsprechende Verbindung herstellen
+	port, err := strconv.Atoi(ldapConfig.Port)
 	if err != nil {
-		return nil, fmt.Errorf("failed to connect to LDAP server: %v", err)
+		return nil, fmt.Errorf("ungültiger Port: %v", err)
+	}
+
+	if port == 636 {
+		// SSL/TLS-Verbindung für Port 636
+		l, err = ldap.DialTLS("tcp", ldapConfig.Server+":"+ldapConfig.Port, &tls.Config{InsecureSkipVerify: true})
+		if err != nil {
+			return nil, fmt.Errorf("failed to connect to LDAP server (TLS): %v", err)
+		}
+	} else if port == 389 {
+		// Unverschlüsselte Verbindung für Port 389
+		l, err = ldap.Dial("tcp", ldapConfig.Server+":"+ldapConfig.Port)
+		if err != nil {
+			return nil, fmt.Errorf("failed to connect to LDAP server: %v", err)
+		}
+	} else {
+		return nil, fmt.Errorf("unsupported LDAP port: %s, use 389 for unencrypted or 636 for TLS/SSL", ldapConfig.Port)
 	}
 	defer l.Close()
 
@@ -122,4 +143,4 @@ func isValidContact(entry *ldap.Entry) bool {
 	telephoneNumber := entry.GetAttributeValue("telephoneNumber")
 
 	return firstName != "" && lastName != "" && telephoneNumber != config.PhoneRules.InvalidNumber
-}
+}
\ No newline at end of file