--- a/pvl/hosts/dhcp.py	Tue Mar 03 11:15:39 2015 +0200
+++ b/pvl/hosts/dhcp.py	Tue Mar 03 11:17:07 2015 +0200
@@ -76,9 +76,12 @@
         extensions = host.extensions.get('dhcp', {})
 
         for block in dhcp_host(host, **extensions):
-            if block.key in blocks:
+            if not block.key:
+                # TODO: check for unique Item-Blocks
+                pass
+            elif block.key in blocks:
                 raise HostDHCPError(host, "dhcp {block} conflict with {other}; hosts on multiple networks must use unique ethernet.XXX=... naming".format(block=block, other=blocks[block.key]))
-
-            blocks[block.key] = host
+            else:
+                blocks[block.key] = host
 
             yield block