Index: lib/webrick/httpstatus.rb
===================================================================
--- lib/webrick/httpstatus.rb	(revision 35758)
+++ lib/webrick/httpstatus.rb	(working copy)
@@ -88,12 +88,16 @@ module WEBrick
       415 => 'Unsupported Media Type',
       416 => 'Request Range Not Satisfiable',
       417 => 'Expectation Failed',
+      428 => 'Precondition Required',
+      429 => 'Too Many Requests',
+      431 => 'Request Header Fields Too Large',
       500 => 'Internal Server Error',
       501 => 'Not Implemented',
       502 => 'Bad Gateway',
       503 => 'Service Unavailable',
       504 => 'Gateway Timeout',
-      505 => 'HTTP Version Not Supported'
+      505 => 'HTTP Version Not Supported',
+      511 => 'Network Authentication Required',
     }
 
     # Maps a status code to the corresponding Status class
Index: lib/net/http/response.rb
===================================================================
--- lib/net/http/response.rb	(revision 35761)
+++ lib/net/http/response.rb	(working copy)
@@ -55,6 +55,9 @@
 #       415        HTTPUnsupportedMediaType
 #       416        HTTPRequestedRangeNotSatisfiable
 #       417        HTTPExpectationFailed
+#       428        HTTPPreconditionRequired
+#       429        HTTPTooManyRequests
+#       431        HTTPRequestHeaderFieldsTooLarge
 #
 #     5xx        HTTPServerError
 #       500        HTTPInternalServerError
@@ -63,6 +66,7 @@
 #       503        HTTPServiceUnavailable
 #       504        HTTPGatewayTimeOut
 #       505        HTTPVersionNotSupported
+#       511        HTTPNetworkAuthenticationRequired
 #
 #     xxx        HTTPUnknownResponse
 #
Index: lib/net/http/responses.rb
===================================================================
--- lib/net/http/responses.rb	(revision 35761)
+++ lib/net/http/responses.rb	(working copy)
@@ -116,6 +116,16 @@ end
 class Net::HTTPPreconditionFailed < Net::HTTPClientError            # 412
   HAS_BODY = true
 end
+class Net::HTTPPreconditionRequired < Net::HTTPClientError          # 428
+  HAS_BODY = true
+end
+class Net::HTTPTooManyRequests < Net::HTTPClientError               # 429
+  HAS_BODY = true
+end
+class Net::HTTPRequestHeaderFieldsTooLarge < Net::HTTPClientError   # 431
+  HAS_BODY = true
+end
+
 class Net::HTTPRequestEntityTooLarge < Net::HTTPClientError         # 413
   HAS_BODY = true
 end
@@ -133,22 +143,25 @@ class Net::HTTPExpectationFailed < Net::
   HAS_BODY = true
 end
 
-class Net::HTTPInternalServerError < Net::HTTPServerError   # 500
+class Net::HTTPInternalServerError < Net::HTTPServerError           # 500
+  HAS_BODY = true
+end
+class Net::HTTPNotImplemented < Net::HTTPServerError                # 501
   HAS_BODY = true
 end
-class Net::HTTPNotImplemented < Net::HTTPServerError        # 501
+class Net::HTTPBadGateway < Net::HTTPServerError                    # 502
   HAS_BODY = true
 end
-class Net::HTTPBadGateway < Net::HTTPServerError            # 502
+class Net::HTTPServiceUnavailable < Net::HTTPServerError            # 503
   HAS_BODY = true
 end
-class Net::HTTPServiceUnavailable < Net::HTTPServerError    # 503
+class Net::HTTPGatewayTimeOut < Net::HTTPServerError                # 504
   HAS_BODY = true
 end
-class Net::HTTPGatewayTimeOut < Net::HTTPServerError        # 504
+class Net::HTTPVersionNotSupported < Net::HTTPServerError           # 505
   HAS_BODY = true
 end
-class Net::HTTPVersionNotSupported < Net::HTTPServerError   # 505
+class Net::HTTPNetworkAuthenticationRequired < Net::HTTPServerError # 511
   HAS_BODY = true
 end
 
@@ -198,13 +211,17 @@ class Net::HTTPResponse
     '415' => Net::HTTPUnsupportedMediaType,
     '416' => Net::HTTPRequestedRangeNotSatisfiable,
     '417' => Net::HTTPExpectationFailed,
+    '428' => Net::HTTPPreconditionRequired,
+    '429' => Net::HTTPTooManyRequests,
+    '431' => Net::HTTPRequestHeaderFieldsTooLarge,
 
     '500' => Net::HTTPInternalServerError,
     '501' => Net::HTTPNotImplemented,
     '502' => Net::HTTPBadGateway,
     '503' => Net::HTTPServiceUnavailable,
     '504' => Net::HTTPGatewayTimeOut,
-    '505' => Net::HTTPVersionNotSupported
+    '505' => Net::HTTPVersionNotSupported,
+    '511' => Net::HTTPNetworkAuthenticationRequired,
   }
 end
 
Index: lib/net/http.rb
===================================================================
--- lib/net/http.rb	(revision 35761)
+++ lib/net/http.rb	(working copy)
@@ -347,6 +347,9 @@ module Net   #:nodoc:
   #   HTTPUnsupportedMediaType::            415
   #   HTTPRequestedRangeNotSatisfiable::    416
   #   HTTPExpectationFailed::               417
+  #   HTTPPreconditionRequired::            428
+  #   HTTPTooManyRequests::                 429
+  #   HTTPRequestHeaderFieldsTooLarge::     431
   # HTTPServerError::                    5xx
   #   HTTPInternalServerError::             500
   #   HTTPNotImplemented::                  501
@@ -354,6 +357,7 @@ module Net   #:nodoc:
   #   HTTPServiceUnavailable::              503
   #   HTTPGatewayTimeOut::                  504
   #   HTTPVersionNotSupported::             505
+  #   HTTPNetworkAuthenticationRequired::   511
   #
   # There is also the Net::HTTPBadResponse exception which is raised when
   # there is a protocol error.