diff --git a/utils/he_ipv6/config.py b/utils/he_ipv6/config.py
index 6ebd174..0567b59 100644
--- a/utils/he_ipv6/config.py
+++ b/utils/he_ipv6/config.py
@@ -6,6 +6,7 @@ import re
 ##
 import netaddr
 import requests
+import requests.auth
 from lxml import etree
 from pyroute2 import IPRoute
 ##
@@ -182,7 +183,7 @@ class Allocation(object):
 
 
 class Tunnel(object):
-    def __init__(self, tun_xml):
+    def __init__(self, tun_xml, he_config):
         self.xml = tun_xml
         self.id = None
         self.client = None
@@ -194,6 +195,7 @@ class Tunnel(object):
         self.radvd_dns = None
         self.allocations = {}  # This is a dict of {}[alloc.id] = Allocation obj
         self.assignments = []  # This is a list of Assignment objs
+        self.heconf = he_config
         self.parse()
 
     def _allocations(self):
@@ -251,39 +253,19 @@ class Tunnel(object):
         return(None)
 
 
-class Config(object):
-    default_xsd = 'http://schema.xml.r00t2.io/projects/he_ipv6.xsd'
+class BaseConfig(object):
+    default_xsd = None
 
-    def __init__(self, xml_path, *args, **kwargs):
-        self.xml_path = os.path.abspath(os.path.expanduser(xml_path))
-        if not os.path.isfile(self.xml_path):
-            raise ValueError('xml_path does not exist')
+    def __init__(self, xml_raw, *args, **kwargs):
+        self.raw = xml_raw
         self.tree = None
         self.ns_tree = None
         self.xml = None
         self.ns_xml = None
-        self.raw = None
         self.xsd = None
         self.defaults_parser = None
         self.obj = None
-        self.tunnels = collections.OrderedDict()
-        self.creds = {}
-        self.parse()
-
-    def _creds(self):
-        creds_xml = self.xml.find('creds')
-        for cred_xml in creds_xml.findall('cred'):
-            cred = Credential(cred_xml)
-            self.creds[cred.id] = cred
-        return(None)
-
-    def _tunnels(self):
-        tunnels_xml = self.xml.find('tunnels')
-        for tun_xml in tunnels_xml.findall('tunnel'):
-            tun = Tunnel(tun_xml)
-            tun.creds = self.creds.get(tun.creds_id)
-            self.tunnels[tun.id] = tun
-        return(None)
+        self.parse_xml()
 
     def get_xsd(self):
         raw_xsd = None
@@ -310,18 +292,14 @@ class Config(object):
         self.xsd = etree.XMLSchema(etree.XML(raw_xsd, base_url = base_url))
         return(None)
 
-    def parse(self):
+    def parse_xml(self):
         self.parse_raw()
         self.get_xsd()
         self.populate_defaults()
         self.validate()
-        self.subparse()
         return(None)
 
     def parse_raw(self, parser = None):
-        if not self.raw:
-            with open(self.xml_path, 'rb') as fh:
-                self.raw = fh.read()
         self.xml = etree.fromstring(self.raw, parser = parser)
         self.ns_xml = etree.fromstring(self.raw, parser = parser)
         self.tree = self.xml.getroottree()
@@ -359,13 +337,88 @@ class Config(object):
             raise ValueError('Did not know how to parse obj parameter')
         return(None)
 
-    def subparse(self):
-        self._creds()
-        self._tunnels()
-        return(None)
-
     def validate(self):
         if not self.xsd:
             self.get_xsd()
         self.xsd.assertValid(self.ns_tree)
         return(None)
+
+
+class Config(BaseConfig):
+    default_xsd = 'http://schema.xml.r00t2.io/projects/he_ipv6.xsd'
+
+    def __init__(self, xml_path, *args, **kwargs):
+        self.xml_path = os.path.abspath(os.path.expanduser(xml_path))
+        if not os.path.isfile(self.xml_path):
+            raise ValueError('xml_path does not exist')
+        else:
+            with open(xml_path, 'rb') as fh:
+                raw_xml = fh.read()
+        super().__init__(raw_xml, *args, **kwargs)
+        self.heconf = None
+        self.creds = {}
+        self.tunnels = collections.OrderedDict()
+        self.subparse()
+
+    def _creds(self):
+        creds_xml = self.xml.find('creds')
+        for cred_xml in creds_xml.findall('cred'):
+            cred = Credential(cred_xml)
+            self.creds[cred.id] = cred
+        return(None)
+
+    def _heconf(self):
+        self.heconf = HEConfig(self.creds)
+        return(None)
+
+    def _tunnels(self):
+        tunnels_xml = self.xml.find('tunnels')
+        for tun_xml in tunnels_xml.findall('tunnel'):
+            tun_id = int(tun_xml.attrib['id'].strip())
+            tun = Tunnel(tun_xml, self.heconf.tunnels[tun_id])
+            tun.creds = self.creds.get(tun.creds_id)
+            self.tunnels[tun_id] = tun
+        return(None)
+
+    def subparse(self):
+        self._creds()
+        self._heconf()
+        self._tunnels()
+        return(None)
+
+
+class HEConfig(BaseConfig):
+    default_xsd = 'http://schema.xml.r00t2.io/projects/tunnelbroker.xsd'
+    nsmap = {None: 'https://tunelbroker.net/tunnelInfo.php',
+             'xsi': 'http://www.w3.org/2001/XMLSchema-instance'}
+    attr_qname = etree.QName('http://www.w3.org/2001/XMLSchema-instance', 'schemaLocation')
+    schema_loc = 'https://tunnelbroker.net/tunnelInfo.php {0}'.format(default_xsd)
+
+    def __init__(self, creds, xml_url = 'https://tunnelbroker.net/tunnelInfo.php', *args, **kwargs):
+        self.creds = creds
+        self.url = xml_url
+        req = requests.get(self.url,
+                           auth = requests.auth.HTTPBasicAuth(self.creds.user, self.creds.password))
+        if not req.ok:
+            raise RuntimeError('Could not fetch remote tunnel information')
+        raw_xml = self._add_ns(req.content)
+        super().__init__(raw_xml, *args, **kwargs)
+        self.tunnels = collections.OrderedDict()
+        self.subparse()
+
+    def subparse(self):
+        pass
+
+    def _add_ns(self, raw_xml):
+        # https://mailman-mail5.webfaction.com/pipermail/lxml/20100323/013260.html
+        _xml = etree.fromstring(raw_xml)
+        _nsmap = copy.deepcopy(_xml.nsmap)
+        _nsmap.update(self.nsmap)
+        mod_xml = etree.Element(_xml.tag, {self.attr_qname: self.schema_loc}, nsmap = _nsmap)
+        mod_xml[:] = _xml[:]
+        return(etree.tostring(mod_xml,
+                              encoding = 'UTF-8',
+                              xml_declaration = True,
+                              pretty_print = True,
+                              with_tail = True,
+                              with_comments = True))
diff --git a/utils/he_ipv6/example.tunnelbroker.xml b/utils/he_ipv6/example.tunnelbroker.xml
index 1a13420..34dbfe1 100644
--- a/utils/he_ipv6/example.tunnelbroker.xml
+++ b/utils/he_ipv6/example.tunnelbroker.xml
@@ -12,15 +12,16 @@
   <creds>
     <!--
     Credentials are kept separate from tunnel configuration because you can have multiple (up to 5) tunnels per user.
-    The updateKey is *not* your password! You can find it in the "Advanced" tab of your tunnel's configuration on
-    your tunnelbroker.net panel.
+    You can find the updateKey in the "Advanced" tab of your tunnel's configuration on your tunnelbroker.net panel.
     -->
     <cred id="ipv6user">
       <user>ipv6user</user>
+      <password>someSecretPassword</password>
       <updateKey>xXxXxXxXxXxXxXXX</updateKey>
     </cred>
     <cred id="anotheruser">
       <user>someotheruser</user>
+      <password>anotherPassword</password>
       <updateKey>0000000000000000</updateKey>
     </cred>
   </creds>
@@ -28,14 +29,11 @@
     <!--
     Each tunnel MUST have an "id" and a "creds" attribute. The "creds" attribute should reference an "id" of a
     creds/cred object.
-    The tunnel ID can be found by logging into your tunnelbroker.net pannel, clicking on the tunnel you wish to use, and
+    The tunnel ID can be found by logging into your tunnelbroker.net panel, clicking on the tunnel you wish to use, and
     looking at the URL in your browser.
     It is in the format of https://www.tunnelbroker.net/tunnel_detail.php?tid=[TUNNEL ID]
     So if it takes you to e.g. https://www.tunnelbroker.net/tunnel_detail.php?tid=12345, your tunnel ID would
     be "12345".
-    The below directives give you a Section and Value Name. This refers to the tunnelbroker.net panel page for the
-    specific tunnel you're configuring. e.g. To use the above example, this information is found at
-      https://www.tunnelbroker.net/tunnel_detail.php?tid=12345
     -->
     <tunnel id="12345" creds="ipv6user">
       <!--
diff --git a/utils/he_ipv6/ref b/utils/he_ipv6/ref
index 5862a51..236416a 100644
--- a/utils/he_ipv6/ref
+++ b/utils/he_ipv6/ref
@@ -1,5 +1,5 @@
+## General Info/Networking Configuration
 # https://wiki.archlinux.org/index.php/IPv6_tunnel_broker_setup
-# https://forums.he.net/index.php?topic=3153.0
 # https://gist.github.com/pklaus/960672
 # https://genneko.github.io/playing-with-bsd/networking/freebsd-tunnelv6-he
 # https://journeymangeek.com/?p=228
@@ -8,3 +8,8 @@
 # https://shorewall.org/6to4.htm#idm143
 # https://shorewall.org/6to4.htm#SixInFour
 # https://wiki.ubuntu.com/IPv6#Configure_your_Ubuntu_box_as_a_IPv6_router
+
+## Tunnelbroker API
+# https://forums.he.net/index.php?topic=3153.0 ("The following scripts conform to the Dyn DNS Update API (as documented at http://dyn.com/support/developers/api/).")
+# https://help.dyn.com/remote-access-api/return-codes/
+#
diff --git a/utils/he_ipv6/tunnelbroker.py b/utils/he_ipv6/tunnelbroker.py
index e3a4971..574ad48 100644
--- a/utils/he_ipv6/tunnelbroker.py
+++ b/utils/he_ipv6/tunnelbroker.py
@@ -1,3 +1,5 @@
+import datetime
+import json
 import logging
 import os
 import socket
@@ -14,6 +16,7 @@ class TunnelBroker(object):
     url_ip = 'https://ipv4.clientinfo.square-r00t.net/'
     params_ip = {'raw': '1'}
     url_api = 'https://ipv4.tunnelbroker.net/nic/update'
+    ip_cache = '~/.cache/he_tunnelbroker.my_ip.json'
 
     def __init__(self, conf_xml, tun_id = None, wan_ip = True, update = True, *args, **kwargs):
         self.conf_file = os.path.abspath(os.path.expanduser(conf_xml))
@@ -26,11 +29,18 @@ class TunnelBroker(object):
             self.tun = self._conf.tunnels[tun_id]
         self.iface_name = 'he-{0}'.format(self.tun.id)
         self.wan = wan_ip
+        self.needs_update = False
         self.force_update = update
+        self.ip_cache = os.path.abspath(os.path.expanduser(self.ip_cache))
+        self.cached_ips = []
         self.my_ip = None
         self.iface_idx = None
 
     def _get_my_ip(self):
+        if os.path.isfile(self.ip_cache):
+            with open(self.ip_cache, 'r') as fh:
+                self.cached_ips = [(datetime.datetime.fromtimestamp(i[0]),
+                                    config.IP4(i[1], 32)) for i in json.loads(fh.read())]
         if self.wan:
             logger.debug('WAN IP tunneling enabled; fetching WAN IP.')
             req = requests.get(self.url_ip, params = self.params_ip)
@@ -49,12 +59,19 @@ class TunnelBroker(object):
             self.my_ip = config.IP4(_defrt[0]['attrs']['RTA_PREFSRC'], 32)
             ipr.close()
             logger.debug('Set my_ip to {0}.'.format(self.my_ip.str))
+        chk_tuple = (datetime.datetime.utcnow(), self.my_ip)
+        if self.my_ip.str != self.cached_ips[-1][1].str:
+            self.needs_update = True
+        if self.needs_update:
+            self.cached_ips.append(chk_tuple)
+            with open(self.ip_cache, 'w') as fh:
+                fh.write(json.dumps([(i[0].timestamp(), i[1].str) for i in self.cached_ips], indent = 4))
         return(None)
 
     def start(self):
-        if self.force_update:
-            logger.debug('IP update forced; updating.')
-            self._get_my_ip()
+        self._get_my_ip()
+        if any((self.force_update, self.needs_update)):
+            logger.debug('IP update forced or needed; updating.')
             self.update()
         logger.debug('Attempting to clean up any pre-existing config')
         try:
@@ -184,8 +201,9 @@ class TunnelBroker(object):
         self.tun.radvd.svc.stop()
         return(None)
 
-    def update(self, oneshot = False):
-        self._get_my_ip()
+    def update(self):
+        if not self.my_ip:
+            self._get_my_ip()
         auth_handler = requests.auth.HTTPBasicAuth(self.tun.creds.user, self.tun.creds.key)
         logger.debug('Set auth handler.')
         logger.debug('Requesting IP update at provider.')