=====OpenVPN=====

[[https://openvpn.net|website]]
[[https://en.wikipedia.org/wiki/OpenVPN|wikipedia]]

OpenVPN is a software application for setting up VPN connections. It is currently deployed for ExteNet to allow connection the subnet their mNET systems reside on so we can receive traps for them.

====Setup====

To install OpenVPN on Red Hat first the [[https://access.redhat.com/solutions/3358|EPEL repo]] must be added to yum. Please ensure correct version is installed. 

  wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
  sudo rpm -ivh epel-release-6-8.noarch.rpm
  
  
Once that is done it can be installed as normal through yum 

  sudo yum install openvpn

====Configuration====

Configuration files and certs were provided by ExteNet and placed in the following locations to configure the system:

  /etc/openvpn/mnet-vpn.conf
  /etc/openvpn/mnet/ca.crt
  /etc/openvpn/mnet/client02.crt
  /etc/openvpn/mnet/client02.key

To run it just use the openvpn command pointing to the config file, i.e.

  sudo openvpn /etc/openvpn/mnet-vpn.conf
  
====Start/stop as a Background Service====

  sudo service openvpn start
  sudo service openvpn stop


====openvpn logs====

  /var/log/messages
  
  
====Troubleshooting====

If you encounter the following error when starting openvpn at home: 'Can't assign requested address'

Run the following commands:

Step 1. Open a Terminal window. (Found in Applications, Utilities.)
Step 2. Enter the following commands:
  * sudo ifconfig en1 down
  * sudo route flush
  * sudo ifconfig en1 up
OBS! Please make sure to replace en1 with your actual Internet interface. By default you have:
  * en0: ethernet (wired) interface
  * en1: wlan (wireless) interface


source ref: 
https://www.ibvpn.com/billing/knowledgebase/145/OpenVPN-error-write-UDPv4-Canandsharp039t-assign-requested-address-codeequals49.html