diff --git a/src/allmydata/test/test_iputil.py b/src/allmydata/test/test_iputil.py
index e4e524fa7..1963ac2d4 100644
--- a/src/allmydata/test/test_iputil.py
+++ b/src/allmydata/test/test_iputil.py
@@ -1,14 +1,22 @@
+#!/usr/bin/env python
+
+from allmydata.util import iputil, testutil
 
 from twisted.trial import unittest
-from allmydata.util import iputil
+import re, sys
+
+DOTTED_QUAD_RE=re.compile("^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$")
 
 class ListAddresses(unittest.TestCase):
+    def test_get_local_ip_for(self):
+        addr = iputil.get_local_ip_for('127.0.0.1')
+        self.failUnless(DOTTED_QUAD_RE.match(addr))
+
     def test_list_async(self):
         d = iputil.get_local_addresses_async()
         def _check(addresses):
             self.failUnless(len(addresses) >= 1) # always have localhost
-            self.failUnless("127.0.0.1" in addresses,
-                            "didn't see 127.0.0.1 in %s" % (addresses,))
+            self.failUnless("127.0.0.1" in addresses, addresses)
         d.addCallbacks(_check)
         return d
-
+    test_list_async.timeout=2
diff --git a/src/allmydata/util/iputil.py b/src/allmydata/util/iputil.py
index f1180bff2..82752cd26 100644
--- a/src/allmydata/util/iputil.py
+++ b/src/allmydata/util/iputil.py
@@ -8,6 +8,7 @@ import re, socket, sys
 
 # from Twisted
 from twisted.internet import defer
+from twisted.python import log
 from twisted.internet import reactor
 from twisted.internet.protocol import DatagramProtocol
 from twisted.internet.utils import getProcessOutput
@@ -23,6 +24,9 @@ def get_local_addresses_async(target='A.ROOT-SERVERS.NET'):
         pass the address of a host that you are actually trying to be
         reachable to.
     """
+    if sys.platform == "cygwin":
+        return _cygwin_hack(target)
+
     addresses = set()
     addresses.add(get_local_ip_for(target))
 
@@ -37,13 +41,10 @@ def get_local_addresses_async(target='A.ROOT-SERVERS.NET'):
 def get_local_ip_for(target):
     """Find out what our IP address is for use by a given target.
 
-    Returns a string that holds the IP address which could be used by
-    'target' to connect to us. It might work for them, it might not.
+    @returns: the IP address as a dotted-quad string which could be used by
+        'target' to connect to us. It might work for them, it might not
     """
-    try:
-        target_ipaddr = socket.gethostbyname(target)
-    except socket.gaierror:
-        return "127.0.0.1"
+    target_ipaddr = socket.gethostbyname(target)
     udpprot = DatagramProtocol()
     port = reactor.listenUDP(0, udpprot)
     udpprot.transport.connect(target_ipaddr, 7)
@@ -91,12 +92,20 @@ _netbsd_re = re.compile('^\s+inet (?P<address>\d+\.\d+\.\d+\.\d+)\s.+$', flags=r
 
 # Irix 6.5
 _irix_path = '/usr/etc/ifconfig'
-_irix_args = ('-a',)
 
 # Solaris 2.x
 _sunos_path = '/usr/sbin/ifconfig'
-_sunos_args = ('-a',)
 
+# k: platform string as provided in the value of _platform_map
+# v: tuple of (path_to_tool, args, regex,)
+_tool_map = {
+    "linux": (_linux_path, (), _linux_re,),
+    "win32": (_win32_path, _win32_args, _win32_re,),
+    "cygwin": (_win32_path, _win32_args, _win32_re,),
+    "bsd": (_netbsd_path, _netbsd_args, _netbsd_re,),
+    "irix": (_irix_path, _netbsd_args, _netbsd_re,),
+    "sunos": (_sunos_path, _netbsd_args, _netbsd_re,),
+    }
 def _find_addresses_via_config():
     # originally by Greg Smith, hacked by Zooko to conform to Brian's API
     
@@ -104,29 +113,22 @@ def _find_addresses_via_config():
     if not platform:
         raise UnsupportedPlatformError(sys.platform)
 
-    if platform in ('win32', 'cygwin',):
-        l = []
-        for executable in which(_win32_path):
-            l.append(_query(executable, _win32_re, _win32_args))
-        dl = defer.DeferredList(l)
-        def _gather_results(res):
-            addresses = set()
-            for r in res:
-                if r[0]:
-                    addresses.update(r[1])
-            return addresses
-        dl.addCallback(_gather_results)
-        return dl
-    elif platform == 'linux':
-        return _query(_linux_path, _linux_re)
-    elif platform == 'bsd':
-        return _query(_netbsd_path, _netbsd_re, _netbsd_args)
-    elif platform == 'irix' :
-        return _query(_irix_path, _netbsd_re, _irix_args)
-    elif platform == 'sunos':
-        return _query(_sunos_path, _netbsd_re, _sunos_args)
+    (pathtotool, args, regex,) = _tool_map[platform]
+    
+    l = []
+    for executable in which(pathtotool):
+        l.append(_query(executable, args, regex))
+    dl = defer.DeferredList(l)
+    def _gather_results(res):
+        addresses = set()
+        for r in res:
+            if r[0]:
+                addresses.update(r[1])
+        return addresses
+    dl.addCallback(_gather_results)
+    return dl
 
-def _query(path, regex, args=()):
+def _query(path, args, regex):
     d = getProcessOutput(path, args)
     def _parse(output):
         addresses = set()
@@ -140,3 +142,15 @@ def _query(path, regex, args=()):
         return addresses
     d.addCallback(_parse)
     return d
+
+def _cygwin_hack(target):
+    res = set()
+    for h in [target, "localhost", "127.0.0.1",]:
+        try:
+            res.add(get_local_ip_for(h))
+        except socket.gaierror:
+            pass
+
+    return defer.succeed(res)
+
+