diff --git a/dcl-rdns-generate.py b/dcl-rdns-generate.py
new file mode 100755
index 0000000..1ada5e2
--- /dev/null
+++ b/dcl-rdns-generate.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+
+import ipaddress
+import sys
+
+def hexstr2int(string):
+    return int(string.replace(':', ''), 16)
+
+FIRST_MAC = hexstr2int('02:00:b3:39:79:4d')
+FIRST_V4  = ipaddress.ip_address('185.203.112.2')
+FIRST_V6 =  "2a0a:e5c0:0:2:400:b3ff:fe39:794d"
+
+V6_NAT64_BASE = ipaddress.ip_address("2a0a:e5c0:0:1:0:1::")
+
+def v4_from_mac(mac):
+    """Calculates the IPv4 address from a MAC address.
+
+    mac: string (the colon-separated representation)
+    returns: ipaddress.ip_address object with the v4 address
+    """
+    return FIRST_V4 + (hexstr2int(mac) - FIRST_MAC)
+
+def v4_from_v6(ipv6ip):
+    """Calculates the IPv4 address from the IPv4 address
+
+    ipv6ip: the ip
+    returns: ipaddress.ip_address object with the v4 address
+    """
+
+    return FIRST_V4 + (hexstr2int(ipv6ip) - (hexstr2int(FIRST_V6)))
+
+def v6_from_v4(ipv4):
+    v4addr = ipaddress.ip_address(ipv4)
+    return V6_NAT64_BASE + int(v4addr)
+
+if __name__ == "__main__":
+    first_addr = ipaddress.ip_address(sys.argv[1])
+    last_addr = ipaddress.ip_address(sys.argv[2])
+
+    while True:
+        addr = first_addr.reverse_pointer
+        name = "{}.place5.ungleich.ch".format(str(first_addr).replace(":",""))
+        record = "{}. IN PTR {}.".format(addr, name)
+
+        print(record)
+
+        if first_addr == last_addr:
+            break
+
+        first_addr += 1
+
+    sys.exit(0)
+
+    out = []
+
+    try:
+        out.append(v4_from_v6(addr))
+    except:
+        pass
+
+    try:
+        out.append(v6_from_v4(addr))
+    except:
+        pass
+
+
+    print("{}".format(out))
+
+# test.ch
+# 2a0a:e5c0:0:1:0:1:504a:8a8c
+# 80.74.138.140
+# 1347062412
+#