diff --git a/elements/nagios3/README.md b/elements/nagios3/README.md
index 37fd9450e..d35dc7312 100644
--- a/elements/nagios3/README.md
+++ b/elements/nagios3/README.md
@@ -17,7 +17,8 @@ can be provided via heat. For example:
         os_password: unset
         os_username: admin
         os_tenant_name: admin
-        initial_network_split_key: ctlplane
+        monitor_networks:
+          - ctlplane
 
 Sample heat template with defaults configured for a boot-stack vm located at:
   https://git.openstack.org/cgit/openstack/tripleo-heat-templates
diff --git a/elements/nagios3/bin/refresh-nagios-from-nova b/elements/nagios3/bin/refresh-nagios-from-nova
new file mode 100755
index 000000000..02756b627
--- /dev/null
+++ b/elements/nagios3/bin/refresh-nagios-from-nova
@@ -0,0 +1,90 @@
+#!/usr/bin/env python
+# Copyright 2014 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import os
+import subprocess
+import sys
+
+from novaclient.v1_1 import client
+from pynag import Model
+
+conn = client.Client(os.environ['OS_USERNAME'],
+                     os.environ['OS_PASSWORD'],
+                     os.environ['OS_TENANT_NAME'],
+                     os.environ['OS_AUTH_URL'])
+
+if len(sys.argv):
+    target_nets = [unicode(x) for x in sys.argv[1:]]
+else:
+    target_net = [u'default-net']
+
+errors = 0
+reload_nagios = False
+
+for net in target_nets:
+    try:
+        Model.Hostgroup.objects.get_by_name(net)
+    except Exception as e:
+        sys.stderr.write("INFO: creating hostgroup %s\n" % net)
+        hg = Model.Hostgroup()
+        hg.name = net
+        hg.hostgroup_name = net
+        if hg.is_dirty():
+            try:
+                if hg.save():
+                    reload_nagios = True
+            except Exception as e:
+                sys.stderr.write("ERROR: %s\n" % e)
+                errors += 1
+                print(hg)
+
+for server in conn.servers.list():
+    server.get()
+    monitor_nets = set(target_nets) & set(server.networks.keys())
+    if not monitor_nets:
+        continue
+    # Prefer first net, and IPv6
+    for net in target_nets:
+        if net in server.networks:
+            addrs = server.networks[net]
+            break
+    # If there is a floating IP, thats what we want.
+    addr = addrs[-1]
+    try:
+        host = Model.Host.objects.get_by_name(server.name)
+    except Exception as e:
+        host = Model.Host()
+        sys.stderr.write("INFO: creating host %s\n" % server.name)
+    host.use = 'generic-host'
+    host.name = server.name
+    host.host_name = server.name
+    host.alias = server.name
+    host.hostgroups = '%s,ssh-servers' % (','.join(monitor_nets),)
+    host.address = addr
+    try:
+        if host.save():
+            reload_nagios = True
+    except Exception as e:
+        sys.stderr.write("ERROR: %s\n" % e)
+        errors += 1
+        print(host)
+
+if errors:
+    sys.stderr.write("ERROR: %d error(s).\n" % errors)
+    sys.exit(1)
+
+if reload_nagios:
+    sys.stderr.write("INFO: reloading nagios.")
+    subprocess.call(["service","nagios3","reload"])
diff --git a/elements/nagios3/element-deps b/elements/nagios3/element-deps
index fceae001c..583462c41 100644
--- a/elements/nagios3/element-deps
+++ b/elements/nagios3/element-deps
@@ -1,5 +1,4 @@
 apache2
-openstack-clients
 os-apply-config
 os-refresh-config
 postfix
diff --git a/elements/nagios3/install.d/17-nagios b/elements/nagios3/install.d/17-nagios
index e50785f97..5f39387bd 100755
--- a/elements/nagios3/install.d/17-nagios
+++ b/elements/nagios3/install.d/17-nagios
@@ -9,8 +9,14 @@ sed -i "s/check_external_commands=0/check_external_commands=1/" /etc/nagios3/nag
 if [ -f /etc/nagios3/conf.d/extinfo_nagios2.cfg ]; then
   sed -i "s/base\/debian/debian/g" /etc/nagios3/conf.d/extinfo_nagios2.cfg
 fi
-# set all servers as having ssh
-sed -i '0,/ssh-servers/! s/localhost/*/' /etc/nagios3/conf.d/hostgroups_nagios2.cfg
+mkdir -p /etc/nagios3/pynag
+if ! grep -q '^cfg_dir=/etc/nagios3/pynag' /etc/nagios3/nagios.cfg ; then
+    echo "cfg_dir=/etc/nagios3/pynag" >> /etc/nagios3/nagios.cfg
+fi
+install -m 0755 -o root -g root $(dirname $0)/../bin/refresh-nagios-from-nova /usr/local/bin
+install -m 0644 -o root -g root $(dirname $0)/nagios3-crontab /etc/cron.d/nagios3
+virtualenv /opt/stack/venvs/nagios-tools
+/opt/stack/venvs/nagios-tools/bin/pip install pynag python-novaclient
 # some cleanup
 chmod g+x /var/lib/nagios3/rw
 chmod g+x /var/lib/nagios3
diff --git a/elements/nagios3/install.d/nagios3-crontab b/elements/nagios3/install.d/nagios3-crontab
new file mode 100644
index 000000000..4cb62301f
--- /dev/null
+++ b/elements/nagios3/install.d/nagios3-crontab
@@ -0,0 +1,2 @@
+# Refresh from nova periodically
+*/5 * * * * root bash -c '. /opt/stack/venvs/nagios-tools/bin/activate ; . /etc/nagios3/nova_access_info ; /usr/local/bin/refresh-nagios-from-nova $monitor_networks'
diff --git a/elements/nagios3/os-apply-config/etc/nagios3/nova_access_info b/elements/nagios3/os-apply-config/etc/nagios3/nova_access_info
index c5c918073..e0f12720b 100644
--- a/elements/nagios3/os-apply-config/etc/nagios3/nova_access_info
+++ b/elements/nagios3/os-apply-config/etc/nagios3/nova_access_info
@@ -6,5 +6,5 @@ export OS_TENANT_NAME={{nagios3.os_tenant_name}}
 export COMPUTE_API_VERSION=1.1
 export OS_NO_CACHE=True
 # add initial split network.
-split_key={{nagios3.initial_network_split_key}}
+monitor_networks="{{#nagios3.monitor_networks}}{{.}} {{/nagios3.monitor_networks}}"
 nagiosadmin_pass={{nagios3.adm_web_passwd}}
diff --git a/elements/nagios3/os-refresh-config/post-configure.d/17-nagios b/elements/nagios3/os-refresh-config/post-configure.d/17-nagios
index dc2225095..dbefd52a1 100755
--- a/elements/nagios3/os-refresh-config/post-configure.d/17-nagios
+++ b/elements/nagios3/os-refresh-config/post-configure.d/17-nagios
@@ -1,28 +1,7 @@
 #!/bin/bash
-set -eux
+set -eu
 
-# exit if we cann't source our required data
+# exit if we can't source our required data
 DEFAULTS=/etc/nagios3/nova_access_info
-[ -e $DEFAULTS ] || exit 0
 source $DEFAULTS
-echo "defaults loaded."
 htpasswd -bc /etc/nagios3/htpasswd.users nagiosadmin $nagiosadmin_pass
-nova_ip_list=$(nova list | awk -F"|" '/'$split_key'/ { split($7,x,"="); print x[2] }')
-echo "Found $nova_ip_list"
-for node_ip in $nova_ip_list
-do
-    echo "setup cfg file for $node_ip."
-    # TODO: make host_name & alias real names
-    if [ ! -f /etc/nagios3/conf.d/$node_ip.cfg ]; then
-        cat << _EOF_ >> /etc/nagios3/conf.d/$node_ip.cfg
-define host{
-        use                     generic-host
-        host_name               $node_ip
-        alias                   $node_ip
-        address                 $node_ip
-        }
-_EOF_
-    fi
-done
-
-service nagios3 restart