diff --git a/seed/nsd/dictionaries/20_nsd.xml b/seed/nsd/dictionaries/20_nsd.xml
index 65dfcdc..8fc663d 100644
--- a/seed/nsd/dictionaries/20_nsd.xml
+++ b/seed/nsd/dictionaries/20_nsd.xml
@@ -93,6 +93,7 @@
       <param>/etc/nsd/</param>
       <param type="variable">nsd_reverse_name</param>
       <param>reverse</param>
+      <param name="remove_duplicate_value" type="boolean">True</param>
       <param name="join"></param>
       <param name="multi" type="boolean">True</param>
       <target>nsd_reverse_filenames</target>
diff --git a/seed/nsd/funcs/funcs.py b/seed/nsd/funcs/funcs.py
index 31582bb..1cf4c33 100644
--- a/seed/nsd/funcs/funcs.py
+++ b/seed/nsd/funcs/funcs.py
@@ -44,8 +44,8 @@ def get_reverse_name(network: str) -> str:
     if not network:
         return
     network_obj = ip_network(network)
-    if network_obj.prefixlen != 24:
-        raise ValueError('only netmask "255.255.255.0" is supported for DNS reverse name')
+    if network_obj.prefixlen < 24:
+        raise ValueError('only netmask greater than 24 is supported for DNS reverse name')
     o1, o2, o3, o4 = network.split('.')
     return f'{o3}.{o2}.{o1}.in-addr.arpa.'
 
diff --git a/seed/nsd/templates/nsd.reverse b/seed/nsd/templates/nsd.reverse
index 7ac9f94..077d41e 100644
--- a/seed/nsd/templates/nsd.reverse
+++ b/seed/nsd/templates/nsd.reverse
@@ -1,5 +1,5 @@
 %set %%name = None
-%set %%network = %%ip_network(%%nsd_reverse_network[%%rougail_index])
+%set %%network = %%str(%%nsd_reverse_network[%%rougail_index]).rsplit('.', 1)[0]
 %for %%zone in %%nsd_zones
   %set %%suffix = %%normalize_family(%%zone)
   %set %%hostnames = %%nsd["nsd_zone_" + %%suffix]["hostname_" + %%suffix]["hostname_" + %%suffix]
@@ -23,7 +23,7 @@ $TTL 1800
         IN      NS      %%domain_name_eth0.
       %end if
       %set %%ip = %%hostname['ip_' + %%suffix]
-      %if %%ip_address(%%ip) in %%network
+      %if %%ip.startswith(%%network)
 %set %%id = %%ip.rsplit('.', 1)[1]
 %%id       PTR %%hostname.%%{zone}.
       %end if
diff --git a/seed/nsd/templates/risotto.conf b/seed/nsd/templates/risotto.conf
index 261116a..12d81a7 100644
--- a/seed/nsd/templates/risotto.conf
+++ b/seed/nsd/templates/risotto.conf
@@ -17,9 +17,14 @@ zone:
     name: "%%zone"
     zonefile: "%%{zone}.zone.signed"
 %end for
+%set %%reversed = []
 %for %%reverse in %%nsd_reverse_network
+  %if %%reverse.nsd_reverse_name in %%reversed
+    %continue
+  %end if
 
+%%reversed.append(%%reverse.nsd_reverse_name)%slurp
 zone:
     name: "%%reverse.nsd_reverse_name"
-    zonefile: "%%{reverse.nsd_reverse_name}reverse.signed"
+    zonefile: "%%{reverse.nsd_reverse_name.replace('/', '-')}reverse.signed"
 %end for