diff --git a/IM/ConfManager.py b/IM/ConfManager.py
index dc7db25fd..f0253e34e 100644
--- a/IM/ConfManager.py
+++ b/IM/ConfManager.py
@@ -147,6 +147,9 @@ def run(self):
 		while not self._stop:
 			if self.init_time + self.max_ctxt_time < time.time():
 				ConfManager.logger.debug("Inf ID: " + str(self.inf.id) + ": Max contextualization time passed. Exit thread.")
+				# Kill the ansible processes
+				for vm in self.inf.get_vm_list():
+					vm.kill_check_ctxt_process()
 				return
 
 			vms_configuring = self.check_running_pids(vms_configuring)
diff --git a/IM/VirtualMachine.py b/IM/VirtualMachine.py
index 1ad5e8f7e..255342fbb 100644
--- a/IM/VirtualMachine.py
+++ b/IM/VirtualMachine.py
@@ -525,6 +525,22 @@ def launch_check_ctxt_process(self):
 		t = threading.Thread(target=eval("self.check_ctxt_process"))
 		t.daemon = True
 		t.start()
+		
+	def kill_check_ctxt_process(self):
+		"""
+		Kill the check_ctxt_process thread
+		"""
+		if self.ctxt_pid:
+			if self.ctxt_pid != self.WAIT_TO_PID:
+				ssh = self.inf.vm_master.get_ssh(retry = True)
+				try:
+					ssh.execute("kill -9 " + str(self.ctxt_pid))
+				except:
+					VirtualMachine.logger.exception("Error killing ctxt process with pid: " + str(self.ctxt_pid))
+					pass
+		
+			self.ctxt_pid = None
+			self.configured = False
 	
 	def check_ctxt_process(self):
 		"""
@@ -543,7 +559,7 @@ def check_ctxt_process(self):
 		wait = 0
 		while self.ctxt_pid:
 			if self.ctxt_pid != self.WAIT_TO_PID:
-				ssh = self.inf.vm_master.get_ssh()
+				ssh = self.inf.vm_master.get_ssh(retry = True)
 
 				if self.state in VirtualMachine.NOT_RUNNING_STATES:
 					try:
diff --git a/README b/README
index 16ed92b82..af797df30 100644
--- a/README
+++ b/README
@@ -39,6 +39,8 @@ However, if you install IM from sources you should install:
  * The YAML library for Python, typically available as the 'python-yaml' or 'PyYAML' package.
 
  * The SOAPpy library for Python, typically available as the 'python-soappy' or 'SOAPpy' package.
+ 
+ * The Netaddr library for Python, typically available as the 'python-netaddr' package.
 
  * Ansible (http://www.ansibleworks.com/) to configure nodes in the infrastructures.
    In particular, Ansible 1.4.2+ must be installed.
diff --git a/README.md b/README.md
index 2b5074207..e7f0719ff 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,8 @@ However, if you install IM from sources you should install:
  + The YAML library for Python, typically available as the 'python-yaml' or 'PyYAML' package.
 
  + The SOAPpy library for Python, typically available as the 'python-soappy' or 'SOAPpy' package.
+ 
+ + The Netaddr library for Python, typically available as the 'python-netaddr' package.
 
  + Ansible (http://www.ansibleworks.com/) to configure nodes in the infrastructures.
    In particular, Ansible 1.4.2+ must be installed.
diff --git a/doc/source/manual.rst b/doc/source/manual.rst
index f657c6827..8d43d1785 100644
--- a/doc/source/manual.rst
+++ b/doc/source/manual.rst
@@ -13,6 +13,8 @@ IM needs at least Python 2.6 to run, as well as the next libraries:
 * `PyYAML <http://pyyaml.org/>`_, a YAML parser.
 * `SOAPpy <http://pywebsvcs.sourceforge.net/>`_, a full-featured SOAP library
   (we know it is not actively supported by upstream anymore).
+* `Netaddr <http://pythonhosted.org/netaddr//>`_, A Python library for representing 
+  and manipulating network addresses.
 
 Also, IM uses `Ansible <http://www.ansible.com>`_ (1.4.2 or later) to configure the
 infrastructure nodes.
@@ -20,12 +22,15 @@ infrastructure nodes.
 These components are usually available from the distribution repositories. To
 install them in Debian and Ubuntu based distributions, do::
 
-   $ apt-get install python-ply python-paramiko python-yaml python-soappy ansible
+   $ apt-get install python-ply python-paramiko python-yaml python-soappy python-netaddr ansible
 
 In Red Hat based distributions (RHEL, CentOS, Amazon Linux, Oracle Linux,
 Fedora, etc.), do::
 
-   $ yum install python-ply python-paramiko PyYAML SOAPpy ansible
+   $ yum install python-ply python-paramiko python-netaddr PyYAML SOAPpy ansible
+   
+**WARNING: In some GNU/Linux distributions (RHEL 6 or equivalents) you must NOT install
+the packages 'python-paramiko' and 'python-crypto' with yum. You MUST use pip to install them**
 
 Finally, check the next values in the Ansible configuration file
 :file:`ansible.cfg`, (usually found in :file:`/etc/ansible`)::
diff --git a/setup.py b/setup.py
index 95ccecff3..f2e50f959 100644
--- a/setup.py
+++ b/setup.py
@@ -42,5 +42,5 @@
         long_description="IM is a tool that ease the access and the usability of IaaS clouds by automating the VMI selection, deployment, configuration, software installation, monitoring and update of Virtual Appliances. It supports APIs from a large number of virtual platforms, making user applications cloud-agnostic. In addition it integrates a contextualization system to enable the installation and configuration of all the user required applications providing the user with a fully functional infrastructure.",
         description="IM is a tool to manage virtual infrastructures on Cloud deployments",
         platforms=["any"],
-	install_requires=["ansible >= 1.4","paramiko >= 1.14","PyYAML","SOAPpy","boto >= 2.29","apache-libcloud >= 0.17","ply", "bottle"]
+	install_requires=["ansible >= 1.4","paramiko >= 1.14","PyYAML","SOAPpy","boto >= 2.29","apache-libcloud >= 0.17","ply", "bottle", "netaddr"]
 )