diff --git a/install.py b/install.py
index 08e2152..d42276d 100755
--- a/install.py
+++ b/install.py
@@ -203,18 +203,22 @@ def create_if(name, cfg, mac, dhcp_server_cfg):
         result['BOOTPROTO']='dhcp'
         # default: all <= 192.0.0.0
         # others have to be added explicitly
-        dhcp_server_cfg.append((('0.0.0.0','128.0.0.0'), []))
-        dhcp_server_cfg.append((('128.0.0.0','192.0.0.0'), []))
+        dhcp_server_cfg.append(('0.0.0.0/128.0.0.0', []))
+        dhcp_server_cfg.append(('128.0.0.0/192.0.0.0', []))
         for nw in cfg.split(',')[1:]:
             nw = IPv4Interface(cfg).network
             dhcp_server_cfg.append((nw.with_netmask.split('/'), []))
     else:
         cfgip = IPv4Interface(cfg)
         network = cfgip.network
-        if network.prefixlen == 32:
-            otherip = IPv4Interface('%s/31' % cfgip.ip)
+        if network.prefixlen == 32:  # or no prefix specified
+            otherip = IPv4Interface('%s/24' % cfgip.ip)
             network = otherip.network
-            cfgip = network.network_address + (1 - int(otherip) % 2)
+            if str(cfgip.ip).endswith('.1'):
+                cfgip = network.network_address + 2
+            else:
+                cfgip = network.network_address + 1
+            print(name, network.network_address, cfgip, otherip.ip)
             dhcp_server_cfg.append((network.with_netmask, [(str(otherip.ip), str(otherip.ip))]))
             result['IPADDR'] = str(cfgip)
         else:  # subnet with multiple adresses -> static adresses only. dhcp range not yet implemented
@@ -344,13 +348,13 @@ def handle_config():
                 show.dirty = True
     if cfgfile is None:
         return False
+    to_start = {}
     ifname = ''
     parser = ConfigParser()
-    dh = []
+    dhcp_server_cfg = []
     try:
         parser.read(cfgfile)
         network = dict(parser['NETWORK'])
-        dhcp_server_cfg = []
         for ifname in IFNAMES:
             content = create_if(ifname, network.pop(ifname, 'off'), netaddr_dict[ifname], dhcp_server_cfg)
             content = '\n'.join('%s=%s' % kv for kv in content.items())
@@ -358,19 +362,25 @@ def handle_config():
             if todo and more_info == 'NONE':
                 print('change', ifname)
                 show.dirty = True
-        if dh:
+                to_start[ifname] = 'if_restart'
+        if dhcp_server_cfg:
             content = [DHCP_HEADER]
             for subnet, rangelist in dhcp_server_cfg:
-                dh.append('subnet %s netmask %s {\n' % subnet)
-                dh.append('    option netmask %s;\n' % subnet[1])
+                adr, mask = subnet.split('/')
+                content.append('subnet %s netmask %s {\n' % (adr, mask))
+                #content.append('    option netmask %s;\n' % mask)
                 for rng in rangelist:
-                    dh.append('    range %s %s;\n' % rng)
-                dh.append('}\n')
+                    content.append('    range %s %s;\n' % rng)
+                content.append('}\n')
             content = ''.join(content)
             todo = write_when_new('/etc/dhcp/dhcpd.conf', content)
             if todo:
-                print('change ', ifname)
+                print('change dhcpd.conf')
+                to_start['dhcpd'] = 'restart'
             show.dirty = True
+        elif doit:
+            unix_cmd('systemctl stop dhcpd')
+            unix_cmd('systemctl disable dhcpd')
         content = []
         dirty = False
         for section in parser.sections():
@@ -389,7 +399,6 @@ def handle_config():
         raise
         return False
 
-    to_start = {}
     reload_systemd = False
     for service, template_func in SERVICES.items():
         section = service.upper()
@@ -428,9 +437,13 @@ def handle_config():
         unix_cmd('systemctl daemon-reload')
     for service, action in to_start.items():
         show.dirty = True
-        if action == 'restart':
-            unix_cmd('systemctl restart %s' % service)
-        unix_cmd('systemctl enable %s' % service)
+        if action == 'if_restart':
+            unix_cmd('ifdown %s' % service)
+            unix_cmd('ifup %s' % service)
+        else:
+            if action == 'restart':
+                unix_cmd('systemctl restart %s' % service)
+            unix_cmd('systemctl enable %s' % service)
     return True