diff --git a/linkcheck/dns/ChangeLog b/linkcheck/dns/ChangeLog
index 8367892b..13f10d46 100644
--- a/linkcheck/dns/ChangeLog
+++ b/linkcheck/dns/ChangeLog
@@ -23,5 +23,5 @@ sources:
   Changed: resolver.py
   Added: ifconfig.py
 
-* added search patters for domain names
+* added search patterns for domain names
   Changed: resolver.py
diff --git a/linkcheck/dns/__init__.py b/linkcheck/dns/__init__.py
index c0c1abda..6ea8b197 100644
--- a/linkcheck/dns/__init__.py
+++ b/linkcheck/dns/__init__.py
@@ -18,6 +18,7 @@
 
 __all__ = [
     'dnssec',
+    'e164',
     'exception',
     'flags',
     'inet',
@@ -36,6 +37,7 @@ __all__ = [
     'rdatatype',
     'renderer',
     'resolver',
+    'reversename',
     'rrset',
     'set',
     'tokenizer',
diff --git a/linkcheck/dns/e164.py b/linkcheck/dns/e164.py
new file mode 100644
index 00000000..40bec72e
--- /dev/null
+++ b/linkcheck/dns/e164.py
@@ -0,0 +1,79 @@
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""DNS E.164 helpers
+
+@var public_enum_domain: The DNS public ENUM domain, e164.arpa.
+@type public_enum_domain: linkcheck.dns.name.Name object
+"""
+
+import linkcheck.dns.exception
+import linkcheck.dns.name
+import linkcheck.dns.resolver
+
+public_enum_domain = linkcheck.dns.name.from_text('e164.arpa.')
+
+def from_e164(text, origin=public_enum_domain):
+    """Convert an E.164 number in textual form into a Name object whose
+    value is the ENUM domain name for that number.
+    @param text: an E.164 number in textual form.
+    @type text: str
+    @param origin: The domain in which the number should be constructed.
+    The default is e164.arpa.
+    @type: linkcheck.dns.name.Name object or None
+    @rtype: linkcheck.dns.name.Name object
+    """
+    parts = [d for d in text if d.isdigit()]
+    parts.reverse()
+    return linkcheck.dns.name.from_text('.'.join(parts), origin=origin)
+
+def to_e164(name, origin=public_enum_domain, want_plus_prefix=True):
+    """Convert an ENUM domain name into an E.164 number.
+    @param name: the ENUM domain name.
+    @type name: linkcheck.dns.name.Name object.
+    @param origin: A domain containing the ENUM domain name.  The
+    name is relativized to this domain before being converted to text.
+    @type: linkcheck.dns.name.Name object or None
+    @param want_plus_prefix: if True, add a '+' to the beginning of the
+    returned number.
+    @rtype: str
+    """
+    if not origin is None:
+        name = name.relativize(origin)
+    dlabels = [d for d in name.labels if (d.isdigit() and len(d) == 1)]
+    if len(dlabels) != len(name.labels):
+        raise linkcheck.dns.exception.SyntaxError, 'non-digit labels in ENUM domain name'
+    dlabels.reverse()
+    text = ''.join(dlabels)
+    if want_plus_prefix:
+        text = '+' + text
+    return text
+
+def query(number, domains, resolver=None):
+    """Look for NAPTR RRs for the specified number in the specified domains.
+
+    e.g. lookup('16505551212', ['e164.dnspython.org.', 'e164.arpa.'])
+    """
+    if resolver is None:
+        resolver = linkcheck.dns.resolver.get_default_resolver()
+    for domain in domains:
+        if isinstance(domain, (str, unicode)):
+            domain = linkcheck.dns.name.from_text(domain)
+        qname = linkcheck.dns.e164.from_e164(number, domain)
+        try:
+            return linkcheck.dns.resolver.query(qname, 'NAPTR')
+        except linkcheck.dns.resolver.NXDOMAIN:
+            pass
+    raise linkcheck.dns.resolver.NXDOMAIN
diff --git a/linkcheck/dns/inet.py b/linkcheck/dns/inet.py
index bd85d8bb..662680aa 100644
--- a/linkcheck/dns/inet.py
+++ b/linkcheck/dns/inet.py
@@ -89,3 +89,20 @@ def inet_ntop(family, address):
         return linkcheck.dns.ipv6.inet_ntoa(address)
     else:
         raise NotImplementedError
+
+def is_multicast(text):
+    """Is the textual-form network address a multicast address?
+
+    @param text: the textual address
+    @raises ValueError: the address family cannot be determined from the input.
+    @rtype: bool
+    """
+    try:
+        first = ord(linkcheck.dns.ipv4.inet_aton(text)[0])
+        return (first >= 224 and first <= 239)
+    except:
+        try:
+            first = ord(linkcheck.dns.ipv6.inet_aton(text)[0])
+            return (first == 255)
+        except:
+            raise ValueError
diff --git a/linkcheck/dns/ipv6.py b/linkcheck/dns/ipv6.py
index 159fde4a..3f921e58 100644
--- a/linkcheck/dns/ipv6.py
+++ b/linkcheck/dns/ipv6.py
@@ -14,6 +14,8 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
+"""IPv6 helper functions."""
+
 import re
 
 import linkcheck.dns.exception
diff --git a/linkcheck/dns/message.py b/linkcheck/dns/message.py
index 953353c4..2a696b8f 100644
--- a/linkcheck/dns/message.py
+++ b/linkcheck/dns/message.py
@@ -14,6 +14,8 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
+"""DNS Messages"""
+
 from cStringIO import StringIO
 import random
 import struct
@@ -120,6 +122,10 @@ class Message(object):
     message sequence?  This variable is used when validating TSIG signatures
     on messages which are part of a zone transfer.
     @type first: bool
+    @ivar index: An index of rrsets in the message.  The index key is
+    (section, name, rdclass, rdtype, covers, deleting).  Indexing can be
+    disabled by setting the index to None.
+    @type index: dict
     """
 
     def __init__(self, id=None):
@@ -135,6 +141,7 @@ class Message(object):
         self.edns = -1
         self.ednsflags = 0
         self.payload = 0
+        self.request_payload = 0
         self.keyring = None
         self.keyname = None
         self.request_mac = ''
@@ -149,6 +156,7 @@ class Message(object):
         self.had_tsig = False
         self.multi = False
         self.first = True
+        self.index = {}
 
     def __repr__(self):
         return '<DNS message, ID %r>' % self.id
@@ -200,11 +208,11 @@ class Message(object):
         print >> s, ';ADDITIONAL'
         for rrset in self.additional:
             print >> s, rrset.to_text(origin, relativize, **kw)
-        #
+
         # We strip off the final \n so the caller can print the result without
         # doing weird things to get around eccentricities in Python print
         # formatting
-        #
+
         return s.getvalue()[:-1]
 
     def __eq__(self, other):
@@ -246,6 +254,7 @@ class Message(object):
         """Is other a response to self?
         @rtype: bool"""
         if other.flags & linkcheck.dns.flags.QR == 0 or \
+           self.id != other.id or \
            linkcheck.dns.opcode.from_flags(self.flags) != \
            linkcheck.dns.opcode.from_flags(other.flags):
             return False
@@ -262,6 +271,18 @@ class Message(object):
                 return False
         return True
 
+    def section_number(self, section):
+        if section is self.question:
+            return 0
+        elif section is self.answer:
+            return 1
+        elif section is self.authority:
+            return 2
+        elif section is self.additional:
+            return 3
+        else:
+            raise ValueError, 'unknown section'
+
     def find_rrset(self, section, name, rdclass, rdtype,
                    covers=linkcheck.dns.rdatatype.NONE, deleting=None, create=False,
                    force_unique=False):
@@ -289,14 +310,23 @@ class Message(object):
         @raises KeyError: the RRset was not found and create was False
         @rtype: linkcheck.dns.rrset.RRset object"""
 
+        key = (self.section_number(section),
+               name, rdclass, rdtype, covers, deleting)
         if not force_unique:
-            for rrset in section:
-                if rrset.match(name, rdclass, rdtype, covers, deleting):
+            if not self.index is None:
+                rrset = self.index.get(key)
+                if not rrset is None:
                     return rrset
+            else:
+                for rrset in section:
+                    if rrset.match(name, rdclass, rdtype, covers, deleting):
+                        return rrset
         if not create:
             raise KeyError
         rrset = linkcheck.dns.rrset.RRset(name, rdclass, rdtype, covers, deleting)
         section.append(rrset)
+        if not self.index is None:
+            self.index[key] = rrset
         return rrset
 
     def get_rrset(self, section, name, rdclass, rdtype,
@@ -334,7 +364,7 @@ class Message(object):
             rrset = None
         return rrset
 
-    def to_wire(self, origin=None, max_size=65535, **kw):
+    def to_wire(self, origin=None, max_size=0, **kw):
         """Return a string containing the message in DNS compressed wire
         format.
 
@@ -343,12 +373,23 @@ class Message(object):
 
         @param origin: The origin to be appended to any relative names.
         @type origin: linkcheck.dns.name.Name object
-        @param max_size: The maximum size of the wire format output.
+        @param max_size: The maximum size of the wire format output; default
+        is 0, which means 'the message's request payload, if nonzero, or
+        65536'.
         @type max_size: int
         @raises linkcheck.dns.exception.TooBig: max_size was exceeded
         @rtype: string
         """
 
+        if max_size == 0:
+            if self.request_payload != 0:
+                max_size = self.request_payload
+            else:
+                max_size = 65535
+        if max_size < 512:
+            max_size = 512
+        elif max_size > 65535:
+            max_size = 65535
         r = linkcheck.dns.renderer.Renderer(self.id, self.flags, max_size, origin)
         for rrset in self.question:
             r.add_question(rrset.name, rrset.rdtype, rrset.rdclass)
@@ -396,7 +437,7 @@ class Message(object):
         if keyname is None:
             self.keyname = self.keyring.keys()[0]
         else:
-            if isinstance(keyname, str):
+            if isinstance(keyname, basestring):
                 keyname = linkcheck.dns.name.from_text(keyname)
             self.keyname = keyname
         self.fudge = fudge
@@ -407,23 +448,51 @@ class Message(object):
         self.tsig_error = tsig_error
         self.other_data = other_data
 
-    def use_edns(self, edns, ednsflags, payload):
+    def use_edns(self, edns=0, ednsflags=0, payload=1280, request_payload=None):
         """Configure EDNS behavior.
-        @param edns: The EDNS level to use.  Specifying None or -1 means
-        'do not use EDNS'.
-        @type edns: int or None
+        @param edns: The EDNS level to use.  Specifying None, False, or -1
+        means 'do not use EDNS', and in this case the other parameters are
+        ignored.  Specifying True is equivalent to specifying 0, i.e. 'use
+        EDNS0'.
+        @type edns: int or bool or None
         @param ednsflags: EDNS flag values.
         @type ednsflags: int
         @param payload: The EDNS sender's payload field, which is the maximum
         size of UDP datagram the sender can handle.
         @type payload: int
+        @param request_payload: The EDNS payload size to use when sending
+        this message.  If not specified, defaults to the value of payload.
+        @type request_payload: int or None
         @see: RFC 2671
         """
-        if edns is None:
+        if edns is None or edns is False:
             edns = -1
+        if edns is True:
+            edns = 0
+        if request_payload is None:
+            request_payload = payload
+        if edns < 0:
+            ednsflags = 0
+            payload = 0
+            request_payload = 0
         self.edns = edns
         self.ednsflags = ednsflags
         self.payload = payload
+        self.request_payload = request_payload
+
+    def want_dnssec(self, wanted=True):
+        """Enable or disable 'DNSSEC desired' flag in requests.
+        @param wanted: Is DNSSEC desired?  If True, EDNS is enabled if
+        required, and then the DO bit is set.  If False, the DO bit is
+        cleared if EDNS is enabled.
+        @type wanted: bool
+        """
+        if wanted:
+            if self.edns < 0:
+                self.use_edns()
+            self.ednsflags |= linkcheck.dns.flags.DO
+        elif self.edns >= 0:
+            self.ednsflags &= ~linkcheck.dns.flags.DO
 
     def rcode(self):
         """Return the rcode.
@@ -890,7 +959,8 @@ def from_file(f):
     return m
 
 
-def make_query(qname, rdtype, rdclass = linkcheck.dns.rdataclass.IN):
+def make_query(qname, rdtype, rdclass = linkcheck.dns.rdataclass.IN,
+               use_edns=None, want_dnssec=False):
     """Make a query message.
 
     The query name, type, and class may all be specified either
@@ -905,8 +975,16 @@ def make_query(qname, rdtype, rdclass = linkcheck.dns.rdataclass.IN):
     @type rdtype: int
     @param rdclass: The desired rdata class; the default is class IN.
     @type rdclass: int
-    @rtype: linkcheck.dns.message.Message object"""
-    if isinstance(qname, str):
+    @rtype: linkcheck.dns.message.Message object
+    @param use_edns: The EDNS level to use; the default is None (no EDNS).
+    See the description of dns.message.Message.use_edns() for the possible
+    values for use_edns and their meanings.
+    @type use_edns: int or bool or None
+    @param want_dnssec: Should the query indicate that DNSSEC is desired?
+    @type want_dnssec: bool
+    @rtype: dns.message.Message object"""
+
+    if isinstance(qname, basestring):
         qname = linkcheck.dns.name.from_text(qname)
     if isinstance(rdtype, str):
         rdtype = linkcheck.dns.rdatatype.from_text(rdtype)
@@ -916,6 +994,8 @@ def make_query(qname, rdtype, rdclass = linkcheck.dns.rdataclass.IN):
     m.flags |= linkcheck.dns.flags.RD
     m.find_rrset(m.question, qname, rdclass, rdtype, create=True,
                  force_unique=True)
+    m.use_edns(use_edns)
+    m.want_dnssec(want_dnssec)
     return m
 
 
diff --git a/linkcheck/dns/name.py b/linkcheck/dns/name.py
index 55d8a36a..c6d69aed 100644
--- a/linkcheck/dns/name.py
+++ b/linkcheck/dns/name.py
@@ -22,10 +22,11 @@
 @type empty: linkcheck.dns.name.Name object
 """
 
-import string
+from cStringIO import StringIO
 import struct
 import sys
 
+import encodings.idna
 import linkcheck.dns.exception
 
 NAMERELN_NONE = 0
@@ -321,7 +322,28 @@ class Name(object):
             l = self.labels[:-1]
         else:
             l = self.labels
-        s = string.join(map(_escapify, l), '.')
+        s = '.'.join(map(_escapify, l))
+        return s
+
+    def to_unicode(self, omit_final_dot = False):
+        """Convert name to Unicode text format.
+
+        IDN ACE lables are converted to Unicode.
+
+        @param omit_final_dot: If True, don't emit the final dot (denoting the
+        root label) for absolute names.  The default is False.
+        @rtype: string
+        """
+
+        if len(self.labels) == 0:
+            return u'@'
+        if len(self.labels) == 1 and self.labels[0] == '':
+            return u'.'
+        if omit_final_dot and self.is_absolute():
+            l = self.labels[:-1]
+        else:
+            l = self.labels
+        s = u'.'.join([encodings.idna.ToUnicode(_escapify(x)) for x in l])
         return s
 
     def to_digestable(self, origin=None):
@@ -352,8 +374,9 @@ class Name(object):
         """Convert name to wire format, possibly compressing it.
 
         @param file: the file where the compressed name is emitted (typically
-        a cStringIO file)
-        @type file: file
+        a cStringIO file)  If None, a string containing the wire name
+        will be returned.
+        @type file: file or None
         @param compress: The compression table.  If None (the default) names
         will not be compressed.
         @type compress: dict
@@ -365,6 +388,12 @@ class Name(object):
         if it is missing, then this exception is raised
         """
 
+        if file is None:
+            file = StringIO()
+            want_return = True
+        else:
+            want_return = False
+
         if not self.is_absolute():
             if origin is None or not origin.is_absolute():
                 raise NeedAbsoluteNameOrOrigin
@@ -384,7 +413,7 @@ class Name(object):
                 value = 0xc000 + pos
                 s = struct.pack('!H', value)
                 file.write(s)
-                return
+                break
             else:
                 if not compress is None and len(n) > 1:
                     pos = file.tell()
@@ -394,6 +423,8 @@ class Name(object):
                 file.write(chr(l))
                 if l > 0:
                     file.write(label)
+        if want_return:
+            return file.getvalue()
 
     def __len__(self):
         """The length of the name (in labels).
@@ -498,6 +529,68 @@ class Name(object):
 root = Name([''])
 empty = Name([])
 
+def from_unicode(text, origin = root):
+    """Convert unicode text into a Name object.
+
+    Lables are encoded in IDN ACE form.
+
+    @rtype: dns.name.Name object
+    """
+
+    if not isinstance(text, unicode):
+        raise ValueError, "input to from_unicode() must be a unicode string"
+    if not (origin is None or isinstance(origin, Name)):
+        raise ValueError, "origin must be a Name or None"
+    labels = []
+    label = u''
+    escaping = False
+    edigits = 0
+    total = 0
+    if text == u'@':
+        text = u''
+    if text:
+        if text == u'.':
+            return Name([''])        # no Unicode "u" on this constant!
+        for c in text:
+            if escaping:
+                if edigits == 0:
+                    if c.isdigit():
+                        total = int(c)
+                        edigits += 1
+                    else:
+                        label += c
+                        escaping = False
+                else:
+                    if not c.isdigit():
+                        raise BadEscape
+                    total *= 10
+                    total += int(c)
+                    edigits += 1
+                    if edigits == 3:
+                        escaping = False
+                        label += chr(total)
+            elif c == u'.' or c == u'\u3002' or \
+                 c == u'\uff0e' or c == u'\uff61':
+                if len(label) == 0:
+                    raise EmptyLabel
+                labels.append(encodings.idna.ToASCII(label))
+                label = u''
+            elif c == u'\\':
+                escaping = True
+                edigits = 0
+                total = 0
+            else:
+                label += c
+        if escaping:
+            raise BadEscape
+        if len(label) > 0:
+            labels.append(encodings.idna.ToASCII(label))
+        else:
+            labels.append('')
+    if (len(labels) == 0 or labels[-1] != '') and not origin is None:
+        labels.extend(list(origin.labels))
+    return Name(labels)
+
 def from_text(text, origin = root):
     """Convert text into a Name object.
     @rtype: linkcheck.dns.name.Name object
@@ -505,6 +598,10 @@ def from_text(text, origin = root):
 
     if not isinstance(text, str):
         raise ValueError, "input to from_text() must be a byte string"
+        if isinstance(text, unicode):
+            return from_unicode(text, origin)
+        else:
+            raise ValueError, "input to from_text() must be a string"
     if not (origin is None or isinstance(origin, Name)):
         raise ValueError, "origin must be a Name or None"
     labels = []
diff --git a/linkcheck/dns/query.py b/linkcheck/dns/query.py
index ed1b6a13..e5239678 100644
--- a/linkcheck/dns/query.py
+++ b/linkcheck/dns/query.py
@@ -47,18 +47,25 @@ def _compute_expiration(timeout):
 
 
 def _wait_for(ir, iw, ix, expiration):
-    if expiration is None:
-        timeout = None
-    else:
-        timeout = expiration - time.time()
-        if timeout <= 0.0:
+    done = False
+    while not done:
+        if expiration is None:
+            timeout = None
+        else:
+            timeout = expiration - time.time()
+            if timeout <= 0.0:
+                raise linkcheck.dns.exception.Timeout
+        try:
+            if timeout is None:
+                (r, w, x) = select.select(ir, iw, ix)
+            else:
+                (r, w, x) = select.select(ir, iw, ix, timeout)
+        except select.error, e:
+            if e.args[0] != errno.EINTR:
+                raise e
+        done = True
+        if len(r) == 0 and len(w) == 0 and len(x) == 0:
             raise linkcheck.dns.exception.Timeout
-    if timeout is None:
-        (r, w, x) = select.select(ir, iw, ix)
-    else:
-        (r, w, x) = select.select(ir, iw, ix, timeout)
-    if len(r) == 0 and len(w) == 0 and len(x) == 0:
-        raise linkcheck.dns.exception.Timeout
 
 def _wait_for_readable(s, expiration):
     _wait_for([s], [], [s], expiration)
@@ -68,7 +75,8 @@ def _wait_for_writable(s, expiration):
     _wait_for([], [s], [s], expiration)
 
 
-def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0):
+def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0,
+        ignore_unexpected=False):
     """Return the response obtained after sending a query via UDP.
 
     @param q: the query
@@ -90,6 +98,9 @@ def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0):
     @param source_port: The port from which to send the message.
     The default is 0.
     @type source_port: int
+    @param ignore_unexpected: If True, ignore responses from unexpected
+    sources.  The default is False.
+    @type ignore_unexpected: bool
     """
     wire = q.to_wire()
     if af is None:
@@ -113,12 +124,19 @@ def udp(q, where, timeout=None, port=53, af=None, source=None, source_port=0):
             s.bind(source)
         _wait_for_writable(s, expiration)
         s.sendto(wire, destination)
-        _wait_for_readable(s, expiration)
-        (wire, from_address) = s.recvfrom(65535)
+        while 1:
+            _wait_for_readable(s, expiration)
+            (wire, from_address) = s.recvfrom(65535)
+            if from_address == destination or \
+               (linkcheck.dns.inet.is_multicast(where) and \
+                from_address[1] == destination[1]):
+                break
+            if not ignore_unexpected:
+                raise UnexpectedSource, \
+                      'got a response from %s instead of %s' % (from_address,
+                                                                destination)
     finally:
         s.close()
-    if from_address != destination:
-        raise UnexpectedSource
     r = linkcheck.dns.message.from_wire(wire, keyring=q.keyring, request_mac=q.mac)
     if not q.is_response(r):
         raise BadResponse
@@ -331,23 +349,23 @@ def xfr (where, zone, rdtype=linkcheck.dns.rdatatype.AXFR,
         if soa_rrset is None:
             if not r.answer or r.answer[0].name != oname:
                 raise linkcheck.dns.exception.FormError, "first RRset is not an SOA"
-            answer_index = 1
             rrset = r.answer[0]
             if rrset.rdtype != linkcheck.dns.rdatatype.SOA:
                 raise linkcheck.dns.exception.FormError
+            answer_index = 1
             soa_rrset = rrset.copy()
             if rdtype == linkcheck.dns.rdatatype.IXFR:
                 if soa_rrset[0].serial == serial:
-                    #
+
                     # We're already up-to-date.
-                    #
+
                     done = True
                 else:
                     expecting_SOA = True
-        #
+
         # Process SOAs in the answer section (other than the initial
         # SOA in the first message).
-        #
+
         for rrset in r.answer[answer_index:]:
             if done:
                 raise linkcheck.dns.exception.FormError, "answers after final SOA"
@@ -362,11 +380,11 @@ def xfr (where, zone, rdtype=linkcheck.dns.rdatatype.AXFR,
                 if rrset == soa_rrset and not delete_mode:
                     done = True
             elif expecting_SOA:
-                #
+
                 # We made an IXFR request and are expecting another
                 # SOA RR, but saw something else, so this must be an
                 # AXFR response.
-                #
+
                 rdtype = linkcheck.dns.rdatatype.AXFR
                 expecting_SOA = False
         if done and q.keyring and not r.had_tsig:
diff --git a/linkcheck/dns/rdata.py b/linkcheck/dns/rdata.py
index 8b79eba6..50d7f614 100644
--- a/linkcheck/dns/rdata.py
+++ b/linkcheck/dns/rdata.py
@@ -171,6 +171,14 @@ class Rdata(object):
 
         raise NotImplementedError
 
+    def validate(self):
+        """Check that the current contents of the rdata's fields are
+        valid.  If you change an rdata by assigning to its fields,
+        it is a good idea to call validate() when you are done making
+        changes.
+        """
+        linkcheck.dns.rdata.from_text(self.rdclass, self.rdtype, self.to_text())
+
     def __repr__(self):
         covers = self.covers()
         if covers == linkcheck.dns.rdatatype.NONE:
@@ -401,11 +409,11 @@ def from_text(rdclass, rdtype, tok, origin = None, relativize = True):
         tok.unget(token)
         if token[0] == linkcheck.dns.tokenizer.IDENTIFIER and \
            token[1] == r'\#':
-            #
+
             # Known type using the generic syntax.  Extract the
             # wire form from the generic syntax, and then run
             # from_wire on it.
-            #
+
             rdata = GenericRdata.from_text(rdclass, rdtype, tok, origin,
                                            relativize)
             return from_wire(rdclass, rdtype, rdata.data, 0, len(rdata.data),
diff --git a/linkcheck/dns/rdataset.py b/linkcheck/dns/rdataset.py
index c7ac6de5..5873923d 100644
--- a/linkcheck/dns/rdataset.py
+++ b/linkcheck/dns/rdataset.py
@@ -26,6 +26,9 @@ import linkcheck.dns.rdataclass
 import linkcheck.dns.rdata
 import linkcheck.dns.set
 
+# define SimpleSet here for backwards compatibility
+SimpleSet = linkcheck.dns.set.Set
+
 class DifferingCovers(linkcheck.dns.exception.DNSException):
     """Raised if an attempt is made to add a SIG/RRSIG whose covered type
     is not the same as that of the other rdatas in the rdataset."""
@@ -100,12 +103,12 @@ class Rdataset(linkcheck.dns.set.Set):
         @param ttl: The TTL
         @type ttl: int"""
 
-        #
+
         # If we're adding a signature, do some special handling to
         # check that the signature covers the same type as the
         # other rdatas in this rdataset.  If this is the first rdata
         # in the set, initialize the covers field.
-        #
+
         if self.rdclass != rd.rdclass or self.rdtype != rd.rdtype:
             raise IncompatibleTypes
         if not ttl is None:
@@ -194,11 +197,11 @@ class Rdataset(linkcheck.dns.set.Set):
         else:
             rdclass = self.rdclass
         if len(self) == 0:
-            #
+
             # Empty rdatasets are used for the question section, and in
             # some dynamic updates, so we don't need to print out the TTL
             # (which is meaningless anyway).
-            #
+
             print >> s, '%s%s%s %s' % (ntext, pad,
                                        linkcheck.dns.rdataclass.to_text(rdclass),
                                        linkcheck.dns.rdatatype.to_text(self.rdtype))
@@ -208,9 +211,9 @@ class Rdataset(linkcheck.dns.set.Set):
                       (ntext, pad, self.ttl, linkcheck.dns.rdataclass.to_text(rdclass),
                        linkcheck.dns.rdatatype.to_text(self.rdtype),
                        rd.to_text(origin=origin, relativize=relativize, **kw))
-        #
+
         # We strip off the final \n for the caller's convenience in printing
-        #
+
         return s.getvalue()[:-1]
 
     def to_wire(self, name, file, compress=None, origin=None,
diff --git a/linkcheck/dns/rdatatype.py b/linkcheck/dns/rdatatype.py
index 493504c6..1e4a8cff 100644
--- a/linkcheck/dns/rdatatype.py
+++ b/linkcheck/dns/rdatatype.py
@@ -72,9 +72,12 @@ OPT = 41
 APL = 42
 DS = 43
 SSHFP = 44
+IPSECKEY = 45
 RRSIG = 46
 NSEC = 47
 DNSKEY = 48
+DHCID = 49
+SPF = 99
 UNSPEC = 103
 TKEY = 249
 TSIG = 250
@@ -126,9 +129,12 @@ _by_text = {
     'APL' : APL,
     'DS' : DS,
     'SSHFP' : SSHFP,
+    'IPSECKEY' : IPSECKEY,
     'RRSIG' : RRSIG,
     'NSEC' : NSEC,
     'DNSKEY' : DNSKEY,
+    'DHCID' : DHCID,
+    'SPF' : SPF,
     'UNSPEC' : UNSPEC,
     'TKEY' : TKEY,
     'TSIG' : TSIG,
diff --git a/linkcheck/dns/rdtypes/ANY/LOC.py b/linkcheck/dns/rdtypes/ANY/LOC.py
index b6b84edd..88408c65 100644
--- a/linkcheck/dns/rdtypes/ANY/LOC.py
+++ b/linkcheck/dns/rdtypes/ANY/LOC.py
@@ -59,7 +59,7 @@ def _tuple_to_float(what):
     value += float(what[1]) / 60.0
     value += float(what[2]) / 3600.0
     value += float(what[3]) / 3600000.0
-    return value
+    return sign * value
 
 def _encode_size(what, desc):
     what = long(what);
diff --git a/linkcheck/dns/rdtypes/ANY/SPF.py b/linkcheck/dns/rdtypes/ANY/SPF.py
new file mode 100644
index 00000000..eb5c7e09
--- /dev/null
+++ b/linkcheck/dns/rdtypes/ANY/SPF.py
@@ -0,0 +1,22 @@
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+import linkcheck.dns.rdtypes.txtbase
+
+class SPF(linkcheck.dns.rdtypes.txtbase.TXTBase):
+    """SPF record
+
+    @see: RFC 4408"""
+    pass
diff --git a/linkcheck/dns/rdtypes/ANY/TXT.py b/linkcheck/dns/rdtypes/ANY/TXT.py
index 4fdd48b9..90ef2ccf 100644
--- a/linkcheck/dns/rdtypes/ANY/TXT.py
+++ b/linkcheck/dns/rdtypes/ANY/TXT.py
@@ -14,73 +14,8 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
-import linkcheck.dns.exception
-import linkcheck.dns.rdata
-import linkcheck.dns.tokenizer
+import linkcheck.dns.rdtypes.txtbase
 
-class TXT(linkcheck.dns.rdata.Rdata):
-    """TXT record
-
-    @ivar strings: the text strings
-    @type strings: list of string
-    @see: RFC 1035"""
-
-    __slots__ = ['strings']
-
-    def __init__(self, rdclass, rdtype, strings):
-        super(TXT, self).__init__(rdclass, rdtype)
-        if isinstance(strings, str):
-            strings = [ strings ]
-        self.strings = strings[:]
-
-    def to_text(self, origin=None, relativize=True, **kw):
-        txt = ''
-        prefix = ''
-        for s in self.strings:
-            txt += '%s"%s"' % (prefix, linkcheck.dns.rdata._escapify(s))
-            prefix = ' '
-        return txt
-
-    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
-        strings = []
-        while 1:
-            (ttype, s) = tok.get()
-            if ttype == linkcheck.dns.tokenizer.EOL or ttype == linkcheck.dns.tokenizer.EOF:
-                break
-            if ttype != linkcheck.dns.tokenizer.QUOTED_STRING:
-                raise linkcheck.dns.exception.DNSSyntaxError, "expected a quoted string"
-            if len(s) > 255:
-                raise linkcheck.dns.exception.DNSSyntaxError, "string too long"
-            strings.append(s)
-        if len(strings) == 0:
-            raise linkcheck.dns.exception.UnexpectedEnd
-        return cls(rdclass, rdtype, strings)
-
-    from_text = classmethod(from_text)
-
-    def to_wire(self, file, compress = None, origin = None):
-        for s in self.strings:
-            l = len(s)
-            assert l < 256
-            byte = chr(l)
-            file.write(byte)
-            file.write(s)
-
-    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
-        strings = []
-        while rdlen > 0:
-            l = ord(wire[current])
-            current += 1
-            rdlen -= 1
-            if l > rdlen:
-                raise linkcheck.dns.exception.FormError
-            s = wire[current : current + l]
-            current += l
-            rdlen -= l
-            strings.append(s)
-        return cls(rdclass, rdtype, strings)
-
-    from_wire = classmethod(from_wire)
-
-    def _cmp(self, other):
-        return cmp(self.strings, other.strings)
+class TXT(linkcheck.dns.rdtypes.txtbase.TXTBase):
+    """TXT record"""
+    pass
diff --git a/linkcheck/dns/rdtypes/ANY/__init__.py b/linkcheck/dns/rdtypes/ANY/__init__.py
index 57312633..156a7b59 100644
--- a/linkcheck/dns/rdtypes/ANY/__init__.py
+++ b/linkcheck/dns/rdtypes/ANY/__init__.py
@@ -21,6 +21,7 @@ __all__ = [
     'CERT',
     'CNAME',
     'DNAME',
+    'DNSKEY',
     'DS',
     'GPOS',
     'HINFO',
@@ -29,16 +30,16 @@ __all__ = [
     'LOC',
     'MX',
     'NS',
+    'NSEC',
     'NXT',
     'PTR',
     'RP',
+    'RRSIG',
     'RT',
     'SIG',
     'SOA',
+    'SPF',
+    'SSHFP',
     'TXT',
     'X25',
-    'RRSIG',
-    'NSEC',
-    'DNSKEY',
-    'SSHFP',
 ]
diff --git a/linkcheck/dns/rdtypes/IN/DHCID.py b/linkcheck/dns/rdtypes/IN/DHCID.py
new file mode 100644
index 00000000..9eccd761
--- /dev/null
+++ b/linkcheck/dns/rdtypes/IN/DHCID.py
@@ -0,0 +1,61 @@
+# -*- coding: iso-8859-1 -*-
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+import linkcheck.dns.exception
+
+class DHCID(linkcheck.dns.rdata.Rdata):
+    """DHCID record
+
+    @ivar data: the data (the content of the RR is opaque as far as the
+    DNS is concerned)
+    @type data: string
+    @see: RFC 4701"""
+
+    __slots__ = ['data']
+
+    def __init__(self, rdclass, rdtype, data):
+        super(DHCID, self).__init__(rdclass, rdtype)
+        self.data = data
+
+    def to_text(self, origin=None, relativize=True, **kw):
+        return linkcheck.dns.rdata._base64ify(self.data)
+
+    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
+        chunks = []
+        while 1:
+            t = tok.get()
+            if t[0] == linkcheck.dns.tokenizer.EOL or t[0] == linkcheck.dns.tokenizer.EOF:
+                break
+            if t[0] != linkcheck.dns.tokenizer.IDENTIFIER:
+                raise linkcheck.dns.exception.SyntaxError
+            chunks.append(t[1])
+        b64 = ''.join(chunks)
+        data = b64.decode('base64_codec')
+        return cls(rdclass, rdtype, data)
+
+    from_text = classmethod(from_text)
+
+    def to_wire(self, file, compress = None, origin = None):
+        file.write(self.data)
+
+    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
+        data = wire[current : current + rdlen]
+        return cls(rdclass, rdtype, data)
+
+    from_wire = classmethod(from_wire)
+
+    def _cmp(self, other):
+        return cmp(self.data, other.data)
diff --git a/linkcheck/dns/rdtypes/IN/IPSECKEY.py b/linkcheck/dns/rdtypes/IN/IPSECKEY.py
new file mode 100644
index 00000000..be1c5d8d
--- /dev/null
+++ b/linkcheck/dns/rdtypes/IN/IPSECKEY.py
@@ -0,0 +1,160 @@
+# -*- coding: iso-8859-1 -*-
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+from cStringIO import StringIO
+import struct
+
+import linkcheck.dns.exception
+import linkcheck.dns.inet
+import linkcheck.dns.name
+
+class IPSECKEY(linkcheck.dns.rdata.Rdata):
+    """IPSECKEY record
+
+    @ivar precedence: the precedence for this key data
+    @type precedence: int
+    @ivar gateway_type: the gateway type
+    @type gateway_type: int
+    @ivar algorithm: the algorithm to use
+    @type algorithm: int
+    @ivar gateway: the public key
+    @type gateway: None, IPv4 address, IPV6 address, or domain name
+    @ivar key: the public key
+    @type key: string
+    @see: RFC 4025"""
+
+    __slots__ = ['precedence', 'gateway_type', 'algorithm', 'gateway', 'key']
+
+    def __init__(self, rdclass, rdtype, precedence, gateway_type, algorithm,
+                 gateway, key):
+        super(IPSECKEY, self).__init__(rdclass, rdtype)
+        if gateway_type == 0:
+            if gateway != '.' and not gateway is None:
+                raise SyntaxError, 'invalid gateway for gateway type 0'
+            gateway = None
+        elif gateway_type == 1:
+            # check that it's OK
+            junk = linkcheck.dns.inet.inet_pton(linkcheck.dns.inet.AF_INET, gateway)
+        elif gateway_type == 2:
+            # check that it's OK
+            junk = linkcheck.dns.inet.inet_pton(linkcheck.dns.inet.AF_INET6, gateway)
+        elif gateway_type == 3:
+            pass
+        else:
+            raise SyntaxError, \
+                  'invalid IPSECKEY gateway type: %d' % gateway_type
+        self.precedence = precedence
+        self.gateway_type = gateway_type
+        self.algorithm = algorithm
+        self.gateway = gateway
+        self.key = key
+
+    def to_text(self, origin=None, relativize=True, **kw):
+        if self.gateway_type == 0:
+            gateway = '.'
+        elif self.gateway_type == 1:
+            gateway = self.gateway
+        elif self.gateway_type == 2:
+            gateway = self.gateway
+        elif self.gateway_type == 3:
+            gateway = str(self.gateway.choose_relativity(origin, relativize))
+        else:
+            raise ValueError, 'invalid gateway type'
+        return '%d %d %d %s %s' % (self.precedence, self.gateway_type,
+                                   self.algorithm, gateway,
+                                   linkcheck.dns.rdata._base64ify(self.key))
+
+    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
+        precedence = tok.get_uint8()
+        gateway_type = tok.get_uint8()
+        algorithm = tok.get_uint8()
+        if gateway_type == 3:
+            gateway = tok.get_name().choose_relativity(origin, relativize)
+        else:
+            gateway = tok.get_string()
+        chunks = []
+        while 1:
+            t = tok.get()
+            if t[0] == linkcheck.dns.tokenizer.EOL or t[0] == linkcheck.dns.tokenizer.EOF:
+                break
+            if t[0] != linkcheck.dns.tokenizer.IDENTIFIER:
+                raise linkcheck.dns.exception.SyntaxError
+            chunks.append(t[1])
+        b64 = ''.join(chunks)
+        key = b64.decode('base64_codec')
+        return cls(rdclass, rdtype, precedence, gateway_type, algorithm,
+                   gateway, key)
+
+    from_text = classmethod(from_text)
+
+    def to_wire(self, file, compress = None, origin = None):
+        header = struct.pack("!BBB", self.precedence, self.gateway_type,
+                             self.algorithm)
+        file.write(header)
+        if self.gateway_type == 0:
+            pass
+        elif self.gateway_type == 1:
+            file.write(linkcheck.dns.inet.inet_pton(linkcheck.dns.inet.AF_INET, self.gateway))
+        elif self.gateway_type == 2:
+            file.write(linkcheck.dns.inet.inet_pton(linkcheck.dns.inet.AF_INET6, self.gateway))
+        elif self.gateway_type == 3:
+            self.gateway.to_wire(file, None, origin)
+        else:
+            raise ValueError, 'invalid gateway type'
+        file.write(self.key)
+
+    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
+        if rdlen < 3:
+            raise linkcheck.dns.exception.FormError
+        header = struct.unpack('!BBB', wire[current : current + 3])
+        gateway_type = header[1]
+        current += 3
+        rdlen -= 3
+        if gateway_type == 0:
+            gateway = None
+        elif gateway_type == 1:
+            gateway = linkcheck.dns.inet.inet_ntop(linkcheck.dns.inet.AF_INET,
+                                         wire[current : current + 4])
+            current += 4
+            rdlen -= 4
+        elif gateway_type == 2:
+            gateway = linkcheck.dns.inet.inet_ntop(linkcheck.dns.inet.AF_INET6,
+                                         wire[current : current + 16])
+            current += 16
+            rdlen -= 16
+        elif gateway_type == 3:
+            (gateway, cused) = linkcheck.dns.name.from_wire(wire[: current + rdlen],
+                                                  current)
+            current += cused
+            rdlen -= cused
+        else:
+            raise linkcheck.dns.exception.FormError, 'invalid IPSECKEY gateway type'
+        key = wire[current : current + rdlen]
+        return cls(rdclass, rdtype, header[0], gateway_type, header[2],
+                   gateway, key)
+
+    from_wire = classmethod(from_wire)
+
+    def _cmp(self, other):
+        f = StringIO()
+        self.to_wire(f)
+        wire1 = f.getvalue()
+        f.seek(0)
+        f.truncate()
+        other.to_wire(f)
+        wire2 = f.getvalue()
+        f.close()
+        return cmp(wire1, wire2)
diff --git a/linkcheck/dns/rdtypes/IN/NAPTR.py b/linkcheck/dns/rdtypes/IN/NAPTR.py
index cd809d94..ed1e6fc9 100644
--- a/linkcheck/dns/rdtypes/IN/NAPTR.py
+++ b/linkcheck/dns/rdtypes/IN/NAPTR.py
@@ -120,7 +120,7 @@ class NAPTR(linkcheck.dns.rdata.Rdata):
 
     def _cmp(self, other):
         sp = struct.pack("!HH", self.order, self.preference)
-        op = struct.pack("!HH", other.order, self.preference)
+        op = struct.pack("!HH", other.order, other.preference)
         v = cmp(sp, op)
         if v == 0:
             v = cmp(self.flags, other.flags)
diff --git a/linkcheck/dns/rdtypes/IN/__init__.py b/linkcheck/dns/rdtypes/IN/__init__.py
index b0ca89ac..62bf237e 100644
--- a/linkcheck/dns/rdtypes/IN/__init__.py
+++ b/linkcheck/dns/rdtypes/IN/__init__.py
@@ -20,11 +20,12 @@ __all__ = [
     'A',
     'AAAA',
     'APL',
+    'DHCID',
     'KX',
-    'PX',
     'NAPTR',
     'NSAP',
     'NSAP_PTR',
+    'PX',
     'SRV',
     'WKS',
 ]
diff --git a/linkcheck/dns/rdtypes/sigbase.py b/linkcheck/dns/rdtypes/sigbase.py
index 5abf8747..7f3f5f09 100644
--- a/linkcheck/dns/rdtypes/sigbase.py
+++ b/linkcheck/dns/rdtypes/sigbase.py
@@ -102,7 +102,7 @@ class SIGBase(linkcheck.dns.rdata.Rdata):
         type_covered = linkcheck.dns.rdatatype.from_text(tok.get_string())
         algorithm = linkcheck.dns.dnssec.algorithm_from_text(tok.get_string())
         labels = tok.get_int()
-        original_ttl = tok.get_uint32()
+        original_ttl = tok.get_ttl()
         expiration = sigtime_to_posixtime(tok.get_string())
         inception = sigtime_to_posixtime(tok.get_string())
         key_tag = tok.get_int()
diff --git a/linkcheck/dns/rdtypes/txtbase.py b/linkcheck/dns/rdtypes/txtbase.py
new file mode 100644
index 00000000..99503120
--- /dev/null
+++ b/linkcheck/dns/rdtypes/txtbase.py
@@ -0,0 +1,88 @@
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""TXT-like base class."""
+
+import linkcheck.dns.exception
+import linkcheck.dns.rdata
+import linkcheck.dns.tokenizer
+
+class TXTBase(linkcheck.dns.rdata.Rdata):
+    """Base class for rdata that is like a TXT record
+
+    @ivar strings: the text strings
+    @type strings: list of string
+    @see: RFC 1035"""
+
+    __slots__ = ['strings']
+
+    def __init__(self, rdclass, rdtype, strings):
+        super(TXTBase, self).__init__(rdclass, rdtype)
+        if isinstance(strings, str):
+            strings = [ strings ]
+        self.strings = strings[:]
+
+    def to_text(self, origin=None, relativize=True, **kw):
+        txt = ''
+        prefix = ''
+        for s in self.strings:
+            txt += '%s"%s"' % (prefix, linkcheck.dns.rdata._escapify(s))
+            prefix = ' '
+        return txt
+
+    def from_text(cls, rdclass, rdtype, tok, origin = None, relativize = True):
+        strings = []
+        while 1:
+            (ttype, s) = tok.get()
+            if ttype == linkcheck.dns.tokenizer.EOL or ttype == linkcheck.dns.tokenizer.EOF:
+                break
+            if ttype != linkcheck.dns.tokenizer.QUOTED_STRING and \
+               ttype != linkcheck.dns.tokenizer.IDENTIFIER:
+                raise linkcheck.dns.exception.SyntaxError, "expected a string"
+            if len(s) > 255:
+                raise linkcheck.dns.exception.SyntaxError, "string too long"
+            strings.append(s)
+        if len(strings) == 0:
+            raise linkcheck.dns.exception.UnexpectedEnd
+        return cls(rdclass, rdtype, strings)
+
+    from_text = classmethod(from_text)
+
+    def to_wire(self, file, compress = None, origin = None):
+        for s in self.strings:
+            l = len(s)
+            assert l < 256
+            byte = chr(l)
+            file.write(byte)
+            file.write(s)
+
+    def from_wire(cls, rdclass, rdtype, wire, current, rdlen, origin = None):
+        strings = []
+        while rdlen > 0:
+            l = ord(wire[current])
+            current += 1
+            rdlen -= 1
+            if l > rdlen:
+                raise linkcheck.dns.exception.FormError
+            s = wire[current : current + l]
+            current += l
+            rdlen -= l
+            strings.append(s)
+        return cls(rdclass, rdtype, strings)
+
+    from_wire = classmethod(from_wire)
+
+    def _cmp(self, other):
+        return cmp(self.strings, other.strings)
diff --git a/linkcheck/dns/resolver.py b/linkcheck/dns/resolver.py
index 1429ea05..5230189b 100644
--- a/linkcheck/dns/resolver.py
+++ b/linkcheck/dns/resolver.py
@@ -343,7 +343,13 @@ class Resolver(object):
         a string, it is used as the name of the file to open; otherwise it
         is treated as the file itself."""
         if isinstance(f, basestring):
-            f = open(f, 'r')
+            try:
+                f = open(f, 'r')
+            except IOError:
+                # /etc/resolv.conf doesn't exist, can't be read, etc.
+                # We'll just use the default resolver configuration.
+                self.nameservers = ['127.0.0.1']
+                return
             want_close = True
         else:
             want_close = False
@@ -405,10 +411,27 @@ class Resolver(object):
         for h in addrinfo[2]:
             self.localhosts.add(h.lower())
 
+    def _determine_split_char(self, entry):
+        #
+        # The windows registry irritatingly changes the list element
+        # delimiter in between ' ' and ',' (and vice-versa) in various
+        # versions of windows.
+        #
+        if entry.find(' ') >= 0:
+            split_char = ' '
+        elif entry.find(',') >= 0:
+            split_char = ','
+        else:
+            # probably a singleton; treat as a space-separated list.
+            split_char = ' '
+        return split_char
+
     def _config_win32_nameservers (self, nameservers, split_char=','):
         """Configure a NameServer registry entry."""
         # we call str() on nameservers to convert it from unicode to ascii
-        ns_list = str(nameservers).split(split_char)
+        nameservers = str(nameservers)
+        split_char = self._determine_split_char(nameservers)
+        ns_list = nameservers.split(split_char)
         for ns in ns_list:
             if not ns in self.nameservers:
                 self.nameservers.append(ns)
@@ -421,7 +444,9 @@ class Resolver(object):
     def _config_win32_search (self, search):
         """Configure a Search registry entry."""
         # we call str() on search to convert it from unicode to ascii
-        search_list = str(search).split(',')
+        search = str(search)
+        split_char = self._determine_split_char(search)
+        search_list = search.split(split_char)
         for s in search_list:
             if not s in self.search:
                 self.search.add(linkcheck.dns.name.from_text(s))
@@ -512,16 +537,10 @@ class Resolver(object):
                             guid = _winreg.EnumKey(interfaces, i)
                             i += 1
                             key = _winreg.OpenKey(interfaces, guid)
+                            if not self._win32_is_nic_enabled(lm, guid, key):
+                                continue
                             try:
-                                # enabled interfaces seem to have a non-empty
-                                # NTEContextList
-                                try:
-                                    (nte, ttype) = _winreg.QueryValueEx(key,
-                                                             'NTEContextList')
-                                except WindowsError:
-                                    nte = None
-                                if nte:
-                                    self._config_win32_fromkey(key)
+                                self._config_win32_fromkey(key)
                             finally:
                                 key.Close()
                         except EnvironmentError:
@@ -531,6 +550,61 @@ class Resolver(object):
         finally:
             lm.Close()
 
+    def _win32_is_nic_enabled(self, lm, guid, interface_key):
+         # Look in the Windows Registry to determine whether the network
+         # interface corresponding to the given guid is enabled.
+         #
+         # (Code contributed by Paul Marks, thanks!)
+         #
+         try:
+             # This hard-coded location seems to be consistent, at least
+             # from Windows 2000 through Vista.
+             connection_key = _winreg.OpenKey(
+                 lm,
+                 r'SYSTEM\CurrentControlSet\Control\Network'
+                 r'\{4D36E972-E325-11CE-BFC1-08002BE10318}'
+                 r'\%s\Connection' % guid)
+
+             try:
+                 # The PnpInstanceID points to a key inside Enum
+                 (pnp_id, ttype) = _winreg.QueryValueEx(
+                     connection_key, 'PnpInstanceID')
+
+                 if ttype != _winreg.REG_SZ:
+                     raise ValueError
+
+                 device_key = _winreg.OpenKey(
+                     lm, r'SYSTEM\CurrentControlSet\Enum\%s' % pnp_id)
+
+                 try:
+                     # Get ConfigFlags for this device
+                     (flags, ttype) = _winreg.QueryValueEx(
+                         device_key, 'ConfigFlags')
+
+                     if ttype != _winreg.REG_DWORD:
+                         raise ValueError
+
+                     # Based on experimentation, bit 0x1 indicates that the
+                     # device is disabled.
+                     return not (flags & 0x1)
+
+                 finally:
+                     device_key.Close()
+             finally:
+                 connection_key.Close()
+         except (EnvironmentError, ValueError):
+             # Pre-vista, enabled interfaces seem to have a non-empty
+             # NTEContextList; this was how dnspython detected enabled
+             # nics before the code above was contributed.  We've retained
+             # the old method since we don't know if the code above works
+             # on Windows 95/98/ME.
+             try:
+                 (nte, ttype) = _winreg.QueryValueEx(interface_key,
+                                                     'NTEContextList')
+                 return nte is not None
+             except WindowsError:
+                 return False
+
     def _compute_timeout(self, start):
         now = time.time()
         if now < start:
@@ -538,7 +612,7 @@ class Resolver(object):
                 # Time going backwards is bad.  Just give up.
                 raise Timeout
             else:
-                # Time went backwards, but only a little. This can
+                # Time went backwards, but only a little.  This can
                 # happen, e.g. under vmware with older linux kernels.
                 # Pretend it didn't happen.
                 now = start
@@ -571,11 +645,7 @@ class Resolver(object):
         @raises NoNameservers: no non-broken nameservers are available to
         answer the question."""
 
-        if isinstance(qname, str):
-            qname = linkcheck.dns.name.from_text(qname, None)
-        elif isinstance(qname, unicode):
-            # Unicode domain names: http://www.faqs.org/rfcs/rfc3490.html
-            qname = encodings.idna.ToASCII(qname)
+        if isinstance(qname, basestring):
             qname = linkcheck.dns.name.from_text(qname, None)
         if isinstance(rdtype, str):
             rdtype = linkcheck.dns.rdatatype.from_text(rdtype)
diff --git a/linkcheck/dns/reversename.py b/linkcheck/dns/reversename.py
new file mode 100644
index 00000000..f5448bcf
--- /dev/null
+++ b/linkcheck/dns/reversename.py
@@ -0,0 +1,75 @@
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""DNS Reverse Map Names.
+
+@var ipv4_reverse_domain: The DNS IPv4 reverse-map domain, in-addr.arpa.
+@type ipv4_reverse_domain: dns.name.Name object
+@var ipv6_reverse_domain: The DNS IPv6 reverse-map domain, ip6.arpa.
+@type ipv6_reverse_domain: dns.name.Name object
+"""
+
+import linkcheck.dns.name
+import linkcheck.dns.ipv6
+import linkcheck.dns.ipv4
+
+ipv4_reverse_domain = linkcheck.dns.name.from_text('in-addr.arpa.')
+ipv6_reverse_domain = linkcheck.dns.name.from_text('ip6.arpa.')
+
+def from_address(text):
+    """Convert an IPv4 or IPv6 address in textual form into a Name object whose
+    value is the reverse-map domain name of the address.
+    @param text: an IPv4 or IPv6 address in textual form (e.g. '127.0.0.1',
+    '::1')
+    @type text: str
+    @rtype: linkcheck.dns.name.Name object
+    """
+    try:
+        parts = list(linkcheck.dns.ipv6.inet_aton(text).encode('hex_codec'))
+        origin = ipv6_reverse_domain
+    except:
+        parts = ['%d' % ord(byte) for byte in linkcheck.dns.ipv4.inet_aton(text)]
+        origin = ipv4_reverse_domain
+    parts.reverse()
+    return linkcheck.dns.name.from_text('.'.join(parts), origin=origin)
+
+def to_address(name):
+    """Convert a reverse map domain name into textual address form.
+    @param name: an IPv4 or IPv6 address in reverse-map form.
+    @type name: linkcheck.dns.name.Name object
+    @rtype: str
+    """
+    if name.is_subdomain(ipv4_reverse_domain):
+        name = name.relativize(ipv4_reverse_domain)
+        labels = list(name.labels)
+        labels.reverse()
+        text = '.'.join(labels)
+        # run through inet_aton() to check syntax and make pretty.
+        return linkcheck.dns.ipv4.inet_ntoa(linkcheck.dns.ipv4.inet_aton(text))
+    elif name.is_subdomain(ipv6_reverse_domain):
+        name = name.relativize(ipv6_reverse_domain)
+        labels = list(name.labels)
+        labels.reverse()
+        parts = []
+        i = 0
+        l = len(labels)
+        while i < l:
+            parts.append(''.join(labels[i:i+4]))
+            i += 4
+        text = ':'.join(parts)
+        # run through inet_aton() to check syntax and make pretty.
+        return linkcheck.dns.ipv6.inet_ntoa(linkcheck.dns.ipv6.inet_aton(text))
+    else:
+        raise linkcheck.dns.exception.SyntaxError, 'unknown reverse-map address family'
diff --git a/linkcheck/dns/rrset.py b/linkcheck/dns/rrset.py
index ba8cf962..2b149ee4 100644
--- a/linkcheck/dns/rrset.py
+++ b/linkcheck/dns/rrset.py
@@ -108,6 +108,13 @@ class RRset(linkcheck.dns.rdataset.Rdataset):
         return super(RRset, self).to_wire(self.name, file, compress, origin,
                                           self.deleting, **kw)
 
+    def to_rdataset(self):
+        """Convert an RRset into an Rdataset.
+
+        @rtype: dns.rdataset.Rdataset object
+        """
+        return linkcheck.dns.rdataset.from_rdata_list(self.ttl, list(self))
+
 
 def from_text_list(name, ttl, rdclass, rdtype, text_rdatas):
     """Create an RRset with the specified name, TTL, class, and type, and with
@@ -116,7 +123,7 @@ def from_text_list(name, ttl, rdclass, rdtype, text_rdatas):
     @rtype: linkcheck.dns.rrset.RRset object
     """
 
-    if isinstance(name, str):
+    if isinstance(name, basestring):
         name = linkcheck.dns.name.from_text(name, None)
     if isinstance(rdclass, str):
         rdclass = linkcheck.dns.rdataclass.from_text(rdclass)
@@ -145,7 +152,7 @@ def from_rdata_list(name, ttl, rdatas):
     @rtype: linkcheck.dns.rrset.RRset object
     """
 
-    if isinstance(name, str):
+    if isinstance(name, basestring):
         name = linkcheck.dns.name.from_text(name, None)
 
     if len(rdatas) == 0:
diff --git a/linkcheck/dns/tokenizer.py b/linkcheck/dns/tokenizer.py
index ea33a56f..50f059a8 100644
--- a/linkcheck/dns/tokenizer.py
+++ b/linkcheck/dns/tokenizer.py
@@ -279,10 +279,10 @@ class Tokenizer(object):
                 elif c == '\n':
                     raise linkcheck.dns.exception.DNSSyntaxError, 'newline in quoted string'
             elif c == '\\':
-                #
+
                 # Treat \ followed by a delimiter as the
                 # delimiter, otherwise leave it alone.
-                #
+
                 c = self._get_char()
                 if c == '' or not c in self.delimiters:
                     self._unget_char(c)
@@ -419,3 +419,9 @@ class Tokenizer(object):
             raise linkcheck.dns.exception.DNSSyntaxError, \
                   'expected EOL or EOF, got %d "%s"' % (ttype, t)
         return t
+
+    def get_ttl(self):
+        (ttype, t) = self.get()
+        if ttype != IDENTIFIER:
+            raise linkcheck.dns.exception.SyntaxError, 'expecting an identifier'
+        return linkcheck.dns.ttl.from_text(t)
diff --git a/linkcheck/dns/ttl.py b/linkcheck/dns/ttl.py
index 4eeebd22..27ba229c 100644
--- a/linkcheck/dns/ttl.py
+++ b/linkcheck/dns/ttl.py
@@ -33,30 +33,33 @@ def from_text(text):
     """
 
     if text.isdigit():
-        return int(text)
-    if not text[0].isdigit():
-        raise BadTTL
-    total = 0
-    current = 0
-    for c in text:
-        if c.isdigit():
-            current *= 10
-            current += int(c)
-        else:
-            c = c.lower()
-            if c == 'w':
-                total += current * 604800
-            elif c == 'd':
-                total += current * 86400
-            elif c == 'h':
-                total += current * 3600
-            elif c == 'm':
-                total += current * 60
-            elif c == 's':
-                total += current
+        total = long(text)
+    else:
+        if not text[0].isdigit():
+            raise BadTTL
+        total = 0L
+        current = 0L
+        for c in text:
+            if c.isdigit():
+                current *= 10
+                current += long(c)
             else:
-                raise BadTTL, "unknown unit '%s'" % c
-            current = 0
-    if not current == 0:
-        raise BadTTL, "trailing integer"
+                c = c.lower()
+                if c == 'w':
+                    total += current * 604800L
+                elif c == 'd':
+                    total += current * 86400L
+                elif c == 'h':
+                    total += current * 3600L
+                elif c == 'm':
+                    total += current * 60L
+                elif c == 's':
+                    total += current
+                else:
+                    raise BadTTL, "unknown unit '%s'" % c
+                current = 0
+        if not current == 0:
+            raise BadTTL, "trailing integer"
+    if total < 0L or total > 2147483647L:
+        raise BadTTL, "TTL should be between 0 and 2^31 - 1 (inclusive)"
     return total
diff --git a/linkcheck/dns/update.py b/linkcheck/dns/update.py
index b5218104..5336d7d4 100644
--- a/linkcheck/dns/update.py
+++ b/linkcheck/dns/update.py
@@ -47,10 +47,8 @@ class Update(linkcheck.dns.message.Message):
         self.flags |= linkcheck.dns.opcode.to_flags(linkcheck.dns.opcode.UPDATE)
         if isinstance(zone, str):
             zone = linkcheck.dns.name.from_text(zone)
-        else:
-            zone = zone.copy()
         self.origin = zone
-        if isinstance(rdclass, str):
+        if isinstance(rdclass, basestring):
             rdclass = linkcheck.dns.rdataclass.from_text(rdclass)
         self.zone_rdclass = rdclass
         self.find_rrset(self.question, self.origin, rdclass, linkcheck.dns.rdatatype.SOA,
@@ -81,7 +79,7 @@ class Update(linkcheck.dns.message.Message):
 
                 - ttl, rdtype, string..."""
 
-        if isinstance(name, str):
+        if isinstance(name, basestring):
             name = linkcheck.dns.name.from_text(name, None)
         if isinstance(args[0], linkcheck.dns.rdataset.Rdataset):
             for rds in args:
@@ -131,7 +129,7 @@ class Update(linkcheck.dns.message.Message):
 
                 - rdtype, [string...]"""
 
-        if isinstance(name, str):
+        if isinstance(name, basestring):
             name = linkcheck.dns.name.from_text(name, None)
         if len(args) == 0:
             rrset = self.find_rrset(self.authority, name, linkcheck.dns.rdataclass.ANY,
@@ -189,7 +187,7 @@ class Update(linkcheck.dns.message.Message):
 
                 - rdtype, string..."""
 
-        if isinstance(name, str):
+        if isinstance(name, basestring):
             name = linkcheck.dns.name.from_text(name, None)
         if len(args) == 0:
             rrset = self.find_rrset(self.answer, name,
@@ -217,7 +215,7 @@ class Update(linkcheck.dns.message.Message):
         """Require that an owner name (and optionally an rdata type) does
         not exist as a prerequisite to the execution of the update."""
 
-        if isinstance(name, str):
+        if isinstance(name, basestring):
             name = linkcheck.dns.name.from_text(name, None)
         if rdtype is None:
             rrset = self.find_rrset(self.answer, name,
@@ -232,7 +230,7 @@ class Update(linkcheck.dns.message.Message):
                                     linkcheck.dns.rdatatype.NONE, None,
                                     True, True)
 
-    def to_wire(self, origin=None, max_size=65535, **kw):
+    def to_wire(self, origin=None, max_size=65535):
         """Return a string containing the update in DNS compressed wire
         format.
         @rtype: string"""
diff --git a/linkcheck/dns/version.py b/linkcheck/dns/version.py
index 12ea3ad3..d270d03e 100644
--- a/linkcheck/dns/version.py
+++ b/linkcheck/dns/version.py
@@ -17,8 +17,8 @@
 """dnspython release version information."""
 
 MAJOR = 1
-MINOR = 3
-MICRO = 2
+MINOR = 6
+MICRO = 0
 RELEASELEVEL = 0x0f
 SERIAL = 0
 
diff --git a/linkcheck/dns/zone.py b/linkcheck/dns/zone.py
index 5216885f..a288f34c 100644
--- a/linkcheck/dns/zone.py
+++ b/linkcheck/dns/zone.py
@@ -39,6 +39,10 @@ class NoNS(BadZone):
     """The zone has no NS RRset at its origin."""
     pass
 
+class UnknownOrigin(BadZone):
+    """The zone's origin is unknown."""
+    pass
+
 class Zone(object):
     """A DNS zone.
 
@@ -101,7 +105,7 @@ class Zone(object):
         return not self.__eq__(other)
 
     def _validate_name(self, name):
-        if isinstance(name, str):
+        if isinstance(name, basestring):
             name = linkcheck.dns.name.from_text(name, None)
         elif not isinstance(name, linkcheck.dns.name.Name):
             raise KeyError, \
@@ -127,22 +131,22 @@ class Zone(object):
         del self.nodes[key]
 
     def __iter__(self):
-        return self.nodes.keys()
+        return self.nodes.iterkeys()
 
     def iterkeys(self):
-        return self.nodes.keys()
+        return self.nodes.iterkeys()
 
     def keys(self):
         return self.nodes.keys()
 
     def itervalues(self):
-        return self.nodes.values()
+        return self.nodes.itervalues()
 
     def values(self):
         return self.nodes.values()
 
     def iteritems(self):
-        return self.nodes.items()
+        return self.nodes.iteritems()
 
     def items(self):
         return self.nodes.items()
@@ -419,7 +423,7 @@ class Zone(object):
             rdtype = linkcheck.dns.rdatatype.from_text(rdtype)
         if isinstance(covers, str):
             covers = linkcheck.dns.rdatatype.from_text(covers)
-        for (name, node) in self.items():
+        for (name, node) in self.iteritems():
             for rds in node:
                 if rdtype == linkcheck.dns.rdatatype.ANY or \
                    (rds.rdtype == rdtype and rds.covers == covers):
@@ -442,7 +446,7 @@ class Zone(object):
             rdtype = linkcheck.dns.rdatatype.from_text(rdtype)
         if isinstance(covers, str):
             covers = linkcheck.dns.rdatatype.from_text(covers)
-        for (name, node) in self.items():
+        for (name, node) in self.iteritems():
             for rds in node:
                 if rdtype == linkcheck.dns.rdatatype.ANY or \
                    (rds.rdtype == rdtype and rds.covers == covers):
@@ -467,16 +471,11 @@ class Zone(object):
         @type nl: string or None
         """
 
-        if sys.hexversion >= 0x02030000:
-            # allow Unicode filenames
-            str_type = basestring
-        else:
-            str_type = str
         if nl is None:
             opts = 'w'
         else:
             opts = 'wb'
-        if isinstance(f, str_type):
+        if isinstance(f, basestring):
             f = file(f, opts)
             want_close = True
         else:
@@ -486,7 +485,7 @@ class Zone(object):
                 names = self.keys()
                 names.sort()
             else:
-                names = self.keys()
+                names = self.iterkeys()
             for n in names:
                 l = self[n].to_text(n, origin=self.origin,
                                     relativize=relativize)
@@ -538,11 +537,14 @@ class _MasterReader(object):
     (None if no $INCLUDE is active).
     @ivar allow_include: is $INCLUDE allowed?
     @type allow_include: bool
+    @ivar check_origin: should sanity checks of the origin node be done?
+    The default is True.
+    @type check_origin: bool
     """
 
     def __init__(self, tok, origin, rdclass, relativize, zone_factory=Zone,
-                 allow_include=False):
-        if isinstance(origin, str):
+                 allow_include=False, check_origin=True):
+        if isinstance(origin, basestring):
             origin = linkcheck.dns.name.from_text(origin)
         self.tok = tok
         self.current_origin = origin
@@ -553,6 +555,7 @@ class _MasterReader(object):
         self.saved_state = []
         self.current_file = None
         self.allow_include = allow_include
+        self.check_origin = check_origin
 
     def _eat_line(self):
         while 1:
@@ -672,6 +675,8 @@ class _MasterReader(object):
                     elif u == '$ORIGIN':
                         self.current_origin = self.tok.get_name()
                         self.tok.get_eol()
+                        if self.zone.origin is None:
+                            self.zone.origin = self.current_origin
                     elif u == '$INCLUDE' and self.allow_include:
                         token = self.tok.get()
                         if token[0] != linkcheck.dns.tokenizer.QUOTED_STRING:
@@ -712,15 +717,19 @@ class _MasterReader(object):
                   "%s:%d: %s" % (filename, line_number, detail)
 
         # Now that we're done reading, do some basic checking of the zone.
-        self.zone.check_origin()
+        if self.check_origin:
+            self.zone.check_origin()
 
-def from_text(text, origin, rdclass = linkcheck.dns.rdataclass.IN, relativize = True,
-              zone_factory=Zone, filename=None, allow_include=False):
+def from_text(text, origin, rdclass = linkcheck.dns.rdataclass.IN,
+              relativize = True, zone_factory=Zone, filename=None,
+              allow_include=False, check_origin=True):
     """Build a zone object from a master file format string.
 
     @param text: the master file format input
     @type text: string.
-    @param origin: The origin of the zone.
+    @param origin: The origin of the zone; if not specified, the first
+    $ORIGIN statement in the master file will determine the origin of the
+    zone.
     @type origin: linkcheck.dns.name.Name object or string
     @param rdclass: The zone's rdata class; the default is class IN.
     @type rdclass: int
@@ -730,9 +739,12 @@ def from_text(text, origin, rdclass = linkcheck.dns.rdataclass.IN, relativize =
     @type zone_factory: function returning a Zone
     @param filename: The filename to emit when describing where an error
     occurred; the default is '<string>'.
+    @type filename: string
     @param allow_include: is $INCLUDE allowed?
     @type allow_include: bool
-    @type filename: string
+    @param check_origin: should sanity checks of the origin node be done?
+    The default is True.
+    @type check_origin: bool
     @raises linkcheck.dns.zone.NoSOA: No SOA RR was found at the zone origin
     @raises linkcheck.dns.zone.NoNS: No NS RRset was found at the zone origin
     @rtype: linkcheck.dns.zone.Zone object
@@ -746,17 +758,21 @@ def from_text(text, origin, rdclass = linkcheck.dns.rdataclass.IN, relativize =
         filename = '<string>'
     tok = linkcheck.dns.tokenizer.Tokenizer(text, filename)
     reader = _MasterReader(tok, origin, rdclass, relativize, zone_factory,
-                           allow_include=allow_include)
+                           allow_include=allow_include,
+                           check_origin=check_origin)
     reader.read()
     return reader.zone
 
 def from_file(f, origin, rdclass = linkcheck.dns.rdataclass.IN, relativize = True,
-              zone_factory=Zone, filename=None, allow_include=True):
+              zone_factory=Zone, filename=None,
+              allow_include=True, check_origin=True):
     """Read a master file and build a zone object.
 
     @param f: file or string.  If I{f} is a string, it is treated
     as the name of a file to open.
-    @param origin: The origin of the zone.
+    @param origin: The origin of the zone; if not specified, the first
+    $ORIGIN statement in the master file will determine the origin of the
+    zone.
     @type origin: linkcheck.dns.name.Name object or string
     @param rdclass: The zone's rdata class; the default is class IN.
     @type rdclass: int
@@ -770,22 +786,18 @@ def from_file(f, origin, rdclass = linkcheck.dns.rdataclass.IN, relativize = Tru
     @type filename: string
     @param allow_include: is $INCLUDE allowed?
     @type allow_include: bool
+    @param check_origin: should sanity checks of the origin node be done?
+    The default is True.
+    @type check_origin: bool
     @raises linkcheck.dns.zone.NoSOA: No SOA RR was found at the zone origin
     @raises linkcheck.dns.zone.NoNS: No NS RRset was found at the zone origin
     @rtype: linkcheck.dns.zone.Zone object
     """
 
-    if sys.hexversion >= 0x02030000:
-        # allow Unicode filenames; turn on universal newline support
-        str_type = basestring
-        opts = 'rU'
-    else:
-        str_type = str
-        opts = 'r'
-    if isinstance(f, str_type):
+    if isinstance(f, basestring):
         if filename is None:
             filename = f
-        f = file(f, opts)
+        f = file(f, 'rU')
         want_close = True
     else:
         if filename is None:
@@ -794,7 +806,7 @@ def from_file(f, origin, rdclass = linkcheck.dns.rdataclass.IN, relativize = Tru
 
     try:
         z = from_text(f, origin, rdclass, relativize, zone_factory,
-                      filename, allow_include)
+                      filename, allow_include, check_origin)
     finally:
         if want_close:
             f.close()
@@ -807,7 +819,7 @@ def from_xfr(xfr, zone_factory=Zone, relativize=True):
     @type xfr: generator of linkcheck.dns.message.Message objects
     @param relativize: should names be relativized?  The default is True.
     It is essential that the relativize setting matches the one specified
-    to dns.query.xfr()
+    to dns.query.xfr().
     @type relativize: bool
     @raises linkcheck.dns.zone.NoSOA: No SOA RR was found at the zone origin
     @raises linkcheck.dns.zone.NoNS: No NS RRset was found at the zone origin
@@ -817,7 +829,10 @@ def from_xfr(xfr, zone_factory=Zone, relativize=True):
     z = None
     for r in xfr:
         if z is None:
-            origin = r.answer[0].name
+            if relativize:
+                origin = r.origin
+            else:
+                origin = r.answer[0].name
             rdclass = r.answer[0].rdclass
             z = zone_factory(origin, rdclass, relativize=relativize)
         for rrset in r.answer:
diff --git a/tests/dns/test_bugs.py b/tests/dns/test_bugs.py
new file mode 100644
index 00000000..5bf1b662
--- /dev/null
+++ b/tests/dns/test_bugs.py
@@ -0,0 +1,44 @@
+# Copyright (C) 2006, 2007 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+import unittest
+
+import linkcheck.dns.rdata
+import linkcheck.dns.rdataclass
+import linkcheck.dns.rdatatype
+import linkcheck.dns.ttl
+
+class BugsTestCase(unittest.TestCase):
+
+    def test_float_LOC(self):
+        rdata = linkcheck.dns.rdata.from_text(linkcheck.dns.rdataclass.IN, linkcheck.dns.rdatatype.LOC,
+                                    "30 30 0.000 N 100 30 0.000 W 10.00m 20m 2000m 20m")
+        self.failUnless(rdata.float_latitude == 30.5)
+        self.failUnless(rdata.float_longitude == -100.5)
+
+    def test_SOA_BIND8_TTL(self):
+        rdata1 = linkcheck.dns.rdata.from_text(linkcheck.dns.rdataclass.IN, linkcheck.dns.rdatatype.SOA,
+                                     "a b 100 1s 1m 1h 1d")
+        rdata2 = linkcheck.dns.rdata.from_text(linkcheck.dns.rdataclass.IN, linkcheck.dns.rdatatype.SOA,
+                                     "a b 100 1 60 3600 86400")
+        self.failUnless(rdata1 == rdata2)
+
+    def test_TTL_bounds_check(self):
+        def bad():
+            ttl = linkcheck.dns.ttl.from_text("2147483648")
+        self.failUnlessRaises(linkcheck.dns.ttl.BadTTL, bad)
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/tests/dns/test_message.py b/tests/dns/test_message.py
index e36edf64..b14a5cf7 100644
--- a/tests/dns/test_message.py
+++ b/tests/dns/test_message.py
@@ -129,7 +129,13 @@ class TestMessage (unittest.TestCase):
     def test_TooBig(self):
         def bad():
             q = linkcheck.dns.message.from_text(query_text)
-            w = q.to_wire(max_size=15)
+            for i in xrange(0, 25):
+                rrset = linkcheck.dns.rrset.from_text('foo%d.' % i, 3600,
+                                            linkcheck.dns.rdataclass.IN,
+                                            linkcheck.dns.rdatatype.A,
+                                            '10.0.0.%d' % i)
+                q.additional.append(rrset)
+            w = q.to_wire(max_size=512)
         self.assertRaises(linkcheck.dns.exception.TooBig, bad)
 
     def test_answer1(self):