diff --git a/hooks/charmhelpers/contrib/network/ip.py b/hooks/charmhelpers/contrib/network/ip.py
index 17df06f..e62e565 100644
--- a/hooks/charmhelpers/contrib/network/ip.py
+++ b/hooks/charmhelpers/contrib/network/ip.py
@@ -140,7 +140,8 @@ def _get_for_address(address, key):
         if address.version == 4 and netifaces.AF_INET in addresses:
             addr = addresses[netifaces.AF_INET][0]['addr']
             netmask = addresses[netifaces.AF_INET][0]['netmask']
-            cidr = netaddr.IPNetwork("%s/%s" % (addr, netmask))
+            network = netaddr.IPNetwork("%s/%s" % (addr, netmask))
+            cidr = network.cidr
             if address in cidr:
                 if key == 'iface':
                     return iface
@@ -149,11 +150,14 @@ def _get_for_address(address, key):
         if address.version == 6 and netifaces.AF_INET6 in addresses:
             for addr in addresses[netifaces.AF_INET6]:
                 if not addr['addr'].startswith('fe80'):
-                    cidr = netaddr.IPNetwork("%s/%s" % (addr['addr'],
-                                                        addr['netmask']))
+                    network = netaddr.IPNetwork("%s/%s" % (addr['addr'],
+                                                           addr['netmask']))
+                    cidr = network.cidr
                     if address in cidr:
                         if key == 'iface':
                             return iface
+                        elif key == 'netmask' and cidr:
+                            return str(cidr).split('/')[1]
                         else:
                             return addr[key]
     return None
diff --git a/hooks/charmhelpers/core/sysctl.py b/hooks/charmhelpers/core/sysctl.py
new file mode 100644
index 0000000..0f29963
--- /dev/null
+++ b/hooks/charmhelpers/core/sysctl.py
@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+__author__ = 'Jorge Niedbalski R. <jorge.niedbalski@canonical.com>'
+
+import yaml
+
+from subprocess import check_call
+
+from charmhelpers.core.hookenv import (
+    log,
+    DEBUG,
+)
+
+
+def create(sysctl_dict, sysctl_file):
+    """Creates a sysctl.conf file from a YAML associative array
+
+    :param sysctl_dict: a dict of sysctl options eg { 'kernel.max_pid': 1337 }
+    :type sysctl_dict: dict
+    :param sysctl_file: path to the sysctl file to be saved
+    :type sysctl_file: str or unicode
+    :returns: None
+    """
+    sysctl_dict = yaml.load(sysctl_dict)
+
+    with open(sysctl_file, "w") as fd:
+        for key, value in sysctl_dict.items():
+            fd.write("{}={}\n".format(key, value))
+
+    log("Updating sysctl_file: %s values: %s" % (sysctl_file, sysctl_dict),
+        level=DEBUG)
+
+    check_call(["sysctl", "-p", sysctl_file])