--- a/pvl/hosts/host.py	Wed Feb 25 14:59:48 2015 +0200
+++ b/pvl/hosts/host.py	Wed Feb 25 15:06:28 2015 +0200
@@ -146,11 +146,11 @@
             ip          - ipaddr.IPv4Address
             ip6         - ipaddr.IPv6Address
             ethernet    - { index: ethernet }
-            alias       - list
+            alias       - [ str ]: generate CNAMEs for given relative names
             owner       - str: LDAP uid
             location    - location (name, domain) or None
-            alias4      - list (CNAME -> A)
-            alias6      - list (CNAME -> AAAA)
+            alias4      - [ str ]: generate additional A records for given relative names
+            alias6      - [ str ]: generate additional AAAA records for given relative names
             forward     - None: generate forward zone A/AAAA records per ip/ip6
                           False: omit A/AAAA records (and any alias= CNAMEs)
                           str: generate forward zone CNAME to given fqdn

--- a/pvl/hosts/tests.py	Wed Feb 25 14:59:48 2015 +0200
+++ b/pvl/hosts/tests.py	Wed Feb 25 15:06:28 2015 +0200
@@ -155,6 +155,41 @@
             ('*.test', 'CNAME'): ['host'],
         })
 
+    def testHostAlias46(self):
+        h = host.Host.build('host', 'domain',
+                ip      = '192.0.2.1',
+                ip6     = '2001:db8::192.0.2.1',
+                alias4  = 'test4',
+                alias6  = 'test6',
+        )
+
+        self.assertZoneEquals(zone.host_forward(h, 'domain'), {
+            ('host', 'A'): ['192.0.2.1'],
+            ('host', 'AAAA'): ['2001:db8::c000:201'],
+            ('test4', 'A'): ['192.0.2.1'],
+            ('test6', 'AAAA'): ['2001:db8::c000:201'],
+        })
+
+    def testHostAlias4Missing(self):
+        h = host.Host.build('host', 'domain',
+                ip6     = '2001:db8::192.0.2.1',
+                alias4  = 'test4',
+                alias6  = 'test6',
+        )
+
+        with self.assertRaises(zone.HostZoneError):
+            self.assertZoneEquals(zone.host_forward(h, 'domain'), { })
+
+    def testHostAlias6Missing(self):
+        h = host.Host.build('host', 'domain',
+                ip      = '192.0.2.1',
+                alias4  = 'test4',
+                alias6  = 'test6',
+        )
+
+        with self.assertRaises(zone.HostZoneError):
+            self.assertZoneEquals(zone.host_forward(h, 'domain'), { })
+
     def testHostForwardAlias(self):
         h = host.Host.build('host', 'domain',
                 forward = 'host.example.net',

--- a/pvl/hosts/zone.py	Wed Feb 25 14:59:48 2015 +0200
+++ b/pvl/hosts/zone.py	Wed Feb 25 15:06:28 2015 +0200
@@ -83,10 +83,16 @@
         yield pvl.dns.ZoneRecord.CNAME(resolve(origin, host.domain, alias), label)
 
     for alias in host.alias4:
+        if not host.ip:
+            raise HostZoneError(host, "alias4={host.alias4} without ip=".format(host=host))
+
         yield pvl.dns.ZoneRecord.A(resolve(origin, host.domain, alias), host.ip)
 
     for alias in host.alias6:
-         yield pvl.dns.ZoneRecord.AAAA(resolve(origin, host.domain, alias), host.ip6)
+        if not host.ip6:
+            raise HostZoneError(host, "alias6={host.alias6} without ip6=".format(host=host))
+
+        yield pvl.dns.ZoneRecord.AAAA(resolve(origin, host.domain, alias), host.ip6)
 
 def host_reverse (host, prefix) :
     """