diff --git a/app/models/aaaa.rb b/app/models/aaaa.rb
new file mode 100644
index 0000000..c0ac10a
--- /dev/null
+++ b/app/models/aaaa.rb
@@ -0,0 +1,4 @@
+class AAAA < Record
+  validates :content, presence: true, ipv6: true
+  validates :name, presence: true, hostname: true
+end
diff --git a/lib/ipv6_validator.rb b/lib/ipv6_validator.rb
new file mode 100644
index 0000000..09780c3
--- /dev/null
+++ b/lib/ipv6_validator.rb
@@ -0,0 +1,21 @@
+require 'ipaddr'
+require 'socket'
+
+class Ipv6Validator < ActiveModel::EachValidator
+
+  def valid_v6?(addr)
+    return false if addr['/'] # IPAddr accepts addr/mask format
+    return false if addr['[']
+    return false if addr[']']
+    IPAddr.new(addr, Socket::AF_INET6)
+    true
+  rescue IPAddr::AddressFamilyError, IPAddr::InvalidAddressError
+    false
+  end
+
+  def validate_each(record, attribute, value)
+    return if valid_v6?(value)
+
+    record.errors[attribute] << 'is not a valid IPv6 address'
+  end
+end
diff --git a/test/factories/aaaa.rb b/test/factories/aaaa.rb
new file mode 100644
index 0000000..75bfcf7
--- /dev/null
+++ b/test/factories/aaaa.rb
@@ -0,0 +1,7 @@
+FactoryGirl.define do
+  factory :aaaa, class: 'AAAA' do
+    domain
+    name { generate(:subdomain) }
+    content '::1'
+  end
+end
diff --git a/test/models/aaaa_test.rb b/test/models/aaaa_test.rb
new file mode 100644
index 0000000..0589acd
--- /dev/null
+++ b/test/models/aaaa_test.rb
@@ -0,0 +1,34 @@
+require 'test_helper'
+
+class AAAAATest < ActiveSupport::TestCase
+  [
+    '::',
+    '2001:db8::',
+    '2001:db8::1',
+    '2001:0db8:0000:0000:0000:0000:0000:0001',
+    '2001:DB8::1',
+  ].each { |ip|
+    test "content valid #{ip}" do
+      rec = build(:aaaa, content: ip)
+      rec.valid?
+      assert_empty rec.errors[:content], "#{ip} should be valid!"
+    end
+  }
+
+  [
+    'noip',
+    'no ip',
+    '1.2.3.4.5',
+    ':',
+    '2001:db8::1::1',
+    '[2001:db8::1]',
+    '2001:0db8:0000:0000:0000:0000:0000:0000:0001',
+  ].each { |ip|
+    test "content invalid #{ip}" do
+      rec = build(:aaaa, content: ip)
+      rec.valid?
+      assert_not_empty rec.errors[:content], "#{name} should be invalid!"
+    end
+  }
+
+end