diff --git a/ostack_validator/schema.py b/ostack_validator/schema.py
index c2e9207..c62ec2c 100644
--- a/ostack_validator/schema.py
+++ b/ostack_validator/schema.py
@@ -165,9 +165,13 @@ class TypeValidatorRegistry:
     return self.__validators[name]
 
 
+class SchemaError(Issue):
+  def __init__(self, message):
+    super(SchemaError, self).__init__(Issue.ERROR, message)
+
 class InvalidValueError(MarkedIssue):
   def __init__(self, message, mark=Mark('', 1, 1)):
-    super(InvalidValueError, self).__init__(Issue.ERROR, message, mark)
+    super(InvalidValueError, self).__init__(Issue.ERROR, 'Invalid value: '+message, mark)
 
 class TypeValidator(object):
   def __init__(self, f):
@@ -187,6 +191,9 @@ def type_validator(name, **kwargs):
     return fn
   return wrap
 
+def isissue(o):
+  return isinstance(o, Issue)
+
 @type_validator('boolean')
 def validate_boolean(s):
   s = s.lower()
@@ -195,42 +202,163 @@ def validate_boolean(s):
   elif s == 'false':
     return False
   else:
-    return InvalidValueError('Invalid value: value should be "true" or "false"')
+    return InvalidValueError('Value should be "true" or "false"')
 
 def validate_enum(s, values=[]):
   if s in values:
     return None
   if len(values) == 0:
-    message = 'there should be no value'
+    message = 'There should be no value'
   elif len(values) == 1:
-    message = 'the only valid value is %s' % values[0]
+    message = 'The only valid value is %s' % values[0]
   else:
-    message = 'valid values are %s and %s' % (', '.join(values[:-1]), values[-1])
-  return InvalidValueError('Invalid value: %s' % message)
+    message = 'Valid values are %s and %s' % (', '.join(values[:-1]), values[-1])
+  return InvalidValueError('%s' % message)
+
+def validate_ipv4_address(s):
+  s = s.strip()
+  parts = s.split('.')
+  if len(parts) == 4:
+    if all([all([c.isdigit() for c in part]) for part in parts]):
+      parts = [int(part) for part in parts]
+      if all([part < 256 for part in parts]):
+        return '.'.join([str(part) for part in parts])
+
+  return InvalidValueError('Value should be ipv4 address')
+
+def validate_ipv4_network(s):
+  s = s.strip()
+  parts = s.split('/')
+  if len(parts) != 2:
+    return InvalidValueError('Should have "/" character separating address and prefix length')
+
+  address, prefix = parts
+  prefix = prefix.strip()
+
+  if prefix.strip() == '':
+    return InvalidValueError('Prefix length is required')
+
+  address = validate_ipv4_address(address)
+  if isissue(address):
+    return address
+
+  if not all([c.isdigit() for c in prefix]):
+    return InvalidValueError('Prefix length should be an integer')
+
+  prefix = int(prefix)
+  if prefix > 32:
+    return InvalidValueError('Prefix length should be less than or equal to 32')
+
+  return '%s/%d' % (address, prefix)
+
+@type_validator('host_address')
+def validate_host_address(s):
+  return validate_ipv4_address(s)
+
+@type_validator('network_address')
+def validate_network_address(s):
+  return validate_ipv4_network(s)
+
+@type_validator('host_and_port')
+def validate_host_and_port(s, default_port=None):
+  parts = s.strip().split(':', 2)
+
+  host_address = validate_host_address(parts[0])
+  if isissue(host_address):
+    return host_address
+
+  if len(parts) == 2:
+    port = validate_port(parts[1])
+    if isissue(port):
+      return port
+  elif default_port:
+    port = default_port
+  else:
+    return InvalidValueError('No port specified')
+
+  return (host_address, port)
 
-@type_validator('host')
 @type_validator('string')
-@type_validator('stringlist')
 def validate_string(s):
   return s
 
 @type_validator('integer')
-@type_validator('port', min=1, max=65535)
 def validate_integer(s, min=None, max=None):
   leading_whitespace_len = 0
-  while s[leading_whitespace_len].isspace(): leading_whitespace_len += 1
+  while leading_whitespace_len < len(s) and s[leading_whitespace_len].isspace(): leading_whitespace_len += 1
 
   s = s.strip()
+  if s == '':
+    return InvalidValueError('Should not be empty')
+
   for i, c in enumerate(s):
     if not c.isdigit() and not ((c == '-') and (i == 0)):
-      return InvalidValueError('Invalid value: only digits are allowed, but found char "%s"' % c, Mark('', 1, i+1+leading_whitespace_len))
+      return InvalidValueError('Only digits are allowed, but found char "%s"' % c, Mark('', 1, i+1+leading_whitespace_len))
 
   v = int(s)
   if min and v < min:
-    return InvalidValueError('Invalid value: should be greater than or equal to %d' % min, Mark('', 1, leading_whitespace_len))
+    return InvalidValueError('Should be greater than or equal to %d' % min, Mark('', 1, leading_whitespace_len))
   if max and v > max:
-    return InvalidValueError('Invalid value: should be less than or equal to %d' % max, Mark('', 1, leading_whitespace_len))
+    return InvalidValueError('Should be less than or equal to %d' % max, Mark('', 1, leading_whitespace_len))
 
   return v
 
+@type_validator('port')
+def validate_port(s, min=1, max=65535):
+  return validate_integer(s, min=min, max=max)
+
+@type_validator('string_list')
+def validate_list(s, element_type='string'):
+  element_type_validator = TypeValidatorRegistry.get_validator(element_type)
+  if not element_type_validator:
+    return SchemaError('Invalid element type "%s"' % element_type)
+
+  result = []
+  s = s.strip()
+
+  if s == '':
+    return result
+
+  values = s.split(',')
+  for value in values:
+    validated_value = element_type_validator.validate(value.strip())
+    if isinstance(validated_value, Issue):
+      # TODO: provide better position reporting
+      return validated_value
+    result.append(validated_value)
+
+  return result
+
+@type_validator('string_dict')
+def validate_dict(s, element_type='string'):
+  element_type_validator = TypeValidatorRegistry.get_validator(element_type)
+  if not element_type_validator:
+    return SchemaError('Invalid element type "%s"' % element_type)
+
+  result = {}
+  s = s.strip()
+
+  if s == '':
+    return result
+
+  pairs = s.split(',')
+  for pair in pairs:
+    key_value = pair.split(':', 2)
+    if len(key_value) < 2:
+      return InvalidValueError('Value should be NAME:VALUE pairs separated by ","')
+
+    key, value = key_value
+    key = key.strip()
+    value = value.strip()
+
+    if key == '':
+      # TODO: provide better position reporting
+      return InvalidValueError('Key name should not be empty')
+
+    validated_value = element_type_validator.validate(value)
+    if isinstance(validated_value, Issue):
+      # TODO: provide better position reporting
+      return validated_value
+    result[key] = validated_value
+  return result
 
diff --git a/ostack_validator/test_type_validators.py b/ostack_validator/test_type_validators.py
index 7552203..417b655 100644
--- a/ostack_validator/test_type_validators.py
+++ b/ostack_validator/test_type_validators.py
@@ -76,9 +76,57 @@ class IntegerTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
     v = self.validator.validate('123')
     self.assertEqual(123, v)
 
+class HostAddressTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'host_address'
+
+  def test_ipv4_address(self):
+    self.assertValid('127.0.0.1')
+
+  def test_returns_address(self):
+    s = '10.0.0.1'
+    v = self.validator.validate(s)
+    self.assertEqual(s, v)
+
+  def test_value_with_less_than_4_numbers_separated_by_dots(self):
+    self.assertInvalid('10.0.0')
+
+  def test_ipv4_like_string_with_numbers_greater_than_255(self):
+    self.assertInvalid('10.0.256.1')
+
+
+class NetworkAddressTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'network_address'
+
+  def test_ipv4_network(self):
+    self.assertValid('127.0.0.1/24')
+
+  def test_returns_address(self):
+    s = '10.0.0.1/32'
+    v = self.validator.validate(s)
+    self.assertEqual(s, v)
+
+  def test_value_with_less_than_4_numbers_separated_by_dots(self):
+    self.assertInvalid('10.0.0/24')
+
+  def test_ipv4_like_string_with_numbers_greater_than_255(self):
+    self.assertInvalid('10.0.256.1/24')
+
+  def test_no_prefix_length(self):
+    self.assertInvalid('10.0.0.0')
+    self.assertInvalid('10.0.0.0/')
+
+  def test_non_integer_prefix_length(self):
+    self.assertInvalid('10.0.0.0/1a')
+
+  def test_prefix_greater_than_32(self):
+    self.assertInvalid('10.0.0.0/33')
+
 class PortTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
   type_name = 'port'
 
+  def test_empty(self):
+    self.assertInvalid('')
+
   def test_positive_integer(self):
     self.assertValid('123')
 
@@ -109,6 +157,78 @@ class PortTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
     v = self.validator.validate('123')
     self.assertEqual(123, v)
 
+class HostAndPortTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'host_and_port'
+
+  def test_ipv4_address(self):
+    self.assertValid('127.0.0.1:80')
+
+  def test_returns_address(self):
+    s = '10.0.0.1:80'
+    v = self.validator.validate(s)
+    self.assertEqual(('10.0.0.1', 80), v)
+
+  def test_value_with_less_than_4_numbers_separated_by_dots(self):
+    self.assertInvalid('10.0.0:1234')
+
+  def test_ipv4_like_string_with_numbers_greater_than_255(self):
+    self.assertInvalid('10.0.256.1:1234')
+
+  def test_no_port(self):
+    self.assertInvalid('10.0.0.1')
+    self.assertInvalid('10.0.0.1:')
+
+  def test_port_is_not_an_integer(self):
+    self.assertInvalid('10.0.0.1:abc')
+
+  def test_port_is_greater_than_65535(self):
+    self.assertInvalid('10.0.0.1:65536')
+
+class StringListTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'string_list'
+
+  def test_empty_value(self):
+    v = self.validator.validate('')
+    self.assertEqual([], v)
+
+  def test_single_value(self):
+    v = self.validator.validate(' foo bar ')
+
+    self.assertIsInstance(v, list)
+    self.assertEqual('foo bar', v[0])
+    self.assertEqual(1, len(v))
+
+  def test_list_of_values(self):
+    v = self.validator.validate(' foo bar, baz ')
+
+    self.assertIsInstance(v, list)
+    self.assertEqual('foo bar', v[0])
+    self.assertEqual('baz', v[1])
+    self.assertEqual(2, len(v))
+
+class StringDictTypeValidatorTests(TypeValidatorTestHelper, unittest.TestCase):
+  type_name = 'string_dict'
+
+  def test_empty_value(self):
+    v = self.validator.validate('')
+    self.assertEqual({}, v)
+
+  def test_single_value(self):
+    v = self.validator.validate(' foo: bar ')
+
+    self.assertIsInstance(v, dict)
+    self.assertEqual('bar', v['foo'])
+    self.assertEqual(1, len(v))
+
+  def test_list_of_values(self):
+    v = self.validator.validate(' foo: bar, baz: 123 ')
+
+    self.assertIsInstance(v, dict)
+    self.assertEqual('bar', v['foo'])
+    self.assertEqual('123', v['baz'])
+    self.assertEqual(2, len(v))
+
+
 if __name__ == '__main__':
   unittest.main()