public String retrieve_associated_ip(int port)
	{
		if (this.ip_port.containsValue(port)) 
		{
			Iterator<String> itr = this.ip_port.keySet().iterator();
			while (itr.hasNext()) 
			{
				String current_ip = itr.next();
				if (this.ip_port.get(current_ip) == port)
					return current_ip;
			}
		}
		return null;
	}