diff -r 0bf8c07e1072 Lib/ftplib.py
--- a/Lib/ftplib.py	Sun Oct 18 23:12:37 2009 +0200
+++ b/Lib/ftplib.py	Sun Oct 18 23:55:30 2009 +0200
@@ -104,6 +104,7 @@ class FTP:
     file = None
     welcome = None
     passiveserver = 1
+    passive_ignore_host = False
 
     # Initialization method (called by class instantiation).
     # Initialize host to localhost, port to standard ftp port
@@ -150,11 +151,16 @@ class FTP:
         self.debugging = level
     debug = set_debuglevel
 
-    def set_pasv(self, val):
+    def set_pasv(self, val, ignore_host=False):
         '''Use passive or active mode for data transfers.
         With a false argument, use the normal PORT mode,
-        With a true argument, use the PASV command.'''
+        With a true argument, use the PASV command.
+        
+        If `ignore_host` is True, the host address returned as part of
+        the PASV response by the server will be ignored. This is to work
+        with servers which return a bogus (e.g. private) address.'''
         self.passiveserver = val
+        self.passive_ignore_host = ignore_host
 
     # Internal: "sanitize" a string for printing
     def sanitize(self, s):
@@ -301,6 +307,8 @@ class FTP:
             host, port = parse227(self.sendcmd('PASV'))
         else:
             host, port = parse229(self.sendcmd('EPSV'), self.sock.getpeername())
+        if self.passive_ignore_host:
+            host = self.host
         return host, port
 
     def ntransfercmd(self, cmd, rest=None):
diff -r 0bf8c07e1072 Lib/test/test_ftplib.py
--- a/Lib/test/test_ftplib.py	Sun Oct 18 23:12:37 2009 +0200
+++ b/Lib/test/test_ftplib.py	Sun Oct 18 23:55:30 2009 +0200
@@ -37,6 +37,8 @@ class DummyDTPHandler(asynchat.async_cha
 
 
 class DummyFTPHandler(asynchat.async_chat):
+    # If non-False, returns a bogus (unroutable) IP as part of a PASV response.
+    bogus_pasv_host = False
 
     def __init__(self, conn):
         asynchat.async_chat.__init__(self, conn)
@@ -90,6 +92,8 @@ class DummyFTPHandler(asynchat.async_cha
         sock.listen(5)
         sock.settimeout(2)
         ip, port = sock.getsockname()[:2]
+        if self.bogus_pasv_host:
+            ip = self.bogus_pasv_host
         ip = ip.replace('.', ','); p1 = port / 256; p2 = port % 256
         self.push('227 entering passive mode (%s,%d,%d)' %(ip, p1, p2))
         conn, addr = sock.accept()
@@ -361,6 +365,15 @@ class TestFTPClass(TestCase):
         # IPv4 is in use, just make sure send_epsv has not been used
         self.assertEqual(self.server.handler.last_received_cmd, 'pasv')
 
+    def test_bogus_pasv(self):
+        self.server.handler.bogus_pasv_host = '255.255.255.255'
+        try:
+            self.client.set_pasv(True, ignore_host=True)
+            received = []
+            self.client.retrbinary('retr', received.append)
+            self.assertEqual(''.join(received), RETR_DATA)
+        finally:
+            self.server.handler.bogus_pasv_host = False
 
 class TestIPv6Environment(TestCase):