diff --git a/lib/puppet/type/host.rb b/lib/puppet/type/host.rb
index be5c2ed72..7f633d989 100755
--- a/lib/puppet/type/host.rb
+++ b/lib/puppet/type/host.rb
@@ -1,88 +1,101 @@
+require 'ipaddr'
+
 module Puppet
     newtype(:host) do
         ensurable
 
         newproperty(:ip) do
             desc "The host's IP address, IPv4 or IPv6."
+
+        validate do |value|
+            addr = IPAddr.new(value)
+        end
+
         end
 
         newproperty(:alias) do
             desc "Any alias the host might have.  Multiple values must be
                 specified as an array.  Note that this state has the same name
                 as one of the metaparams; using this state to set aliases will
                 make those aliases available in your Puppet scripts and also on
                 disk."
 
            def insync?(is)
                 is == @should
             end
             
             def is_to_s(currentvalue = @is)
                 currentvalue = [currentvalue] unless currentvalue.is_a? Array
                 currentvalue.join(" ")
             end
 
             def retrieve
                 is = super
                 case is
                 when String
                     is = is.split(/\s*,\s*/)
                 when Symbol:
                     is = [is]
                 when Array
                     # nothing
                 else
                     raise Puppet::DevError, "Invalid @is type %s" % is.class
                 end
                 return is
             end
 
             # We actually want to return the whole array here, not just the first
             # value.
             def should
                 if defined? @should
                     if @should == [:absent]
                         return :absent
                     else
                         return @should
                     end
                 else
                     return nil
                 end
             end
 
             def should_to_s(newvalue = @should)
                 newvalue.join(" ")
             end
 
             validate do |value|
                 if value =~ /\s/
                     raise Puppet::Error, "Aliases cannot include whitespace"
                 end
             end
         end
 
         newproperty(:target) do
             desc "The file in which to store service information.  Only used by
                 those providers that write to disk (i.e., not NetInfo)."
 
             defaultto { if @resource.class.defaultprovider.ancestors.include?(Puppet::Provider::ParsedFile)
                     @resource.class.defaultprovider.default_target
                 else
                     nil
                 end
             }
         end
 
         newparam(:name) do
             desc "The host name."
 
             isnamevar
+
+            validate do |value|
+               unless value =~ /^([a-z0-9]([-a-z0-9]*[a-z0-9])?\.)+((a[cdefgilmnoqrstuwxz]|aero|arpa)|(b[abdefghijmnorstvwyz]|biz)|(c[acdfghiklmnorsuvxyz]|cat|com|coop)|d[ejkmoz]|(e[ceghrstu]|edu)|f[ijkmor]|(g[abdefghilmnpqrstuwy]|gov)|h[kmnrtu]|(i[delmnoqrst]|info|int)|(j[emop]|jobs)|k[eghimnprwyz]|l[abcikrstuvy]|(m[acdghklmnopqrstuvwxyz]|mil|mobi|museum)|(n[acefgilopruz]|name|net)|(om|org)|(p[aefghklmnrstwy]|pro)|qa|r[eouw]|s[abcdeghijklmnortvyz]|(t[cdfghjklmnoprtvwz]|travel)|u[agkmsyz]|v[aceginu]|w[fs]|y[etu]|z[amw])$/
+                  raise Puppet::Error, "Invalid host name"
+               end
+            end 
         end
 
         @doc = "Installs and manages host entries.  For most systems, these
             entries will just be in ``/etc/hosts``, but some systems (notably OS X)
             will have different solutions."
     end
 end