Resolving The Problem

1. Check the recent entries in /var/log/openvpn.log for errors:

   less +G /var/log/openvpn.log

2. If the recent errors look similar to the following, it indicates the allowlisted public IP is not getting through the firewall and establishing a connection:

   us=601809 Attempting to establish TCP connection with [AF_INET]y.y.y.y.y:443 [nonblock]

   This TCP connection error can be resolved by checking the public IP of your data gateway and allowlist.
3.  If the recent errors look similar to the following, it indicates you are able to connect, but the VPN tunnel cannot be established:

   us=601809 Attempting to establish TCP connection with [AF_INET]y.y.y.y.y:443 [nonblock]
   us=602264 TCP connection established with [AF_INET]y.y.y.y:443
   us=602439 TCP_CLIENT link local: (not bound)
   us=602497 TCP_CLIENT link remote: [AF_INET]y.y.y.y:443
   us=659543 Connection reset, restarting [0]
   us=659838 TCP/UDP: Closing socket
   us=660086 SIGUSR1[soft,connection-reset] received, process restarting

   This error indicates the connection gets reset and the socket is closed before the VPN tunnel is established. It is important to note we do not send resets, we simply drop the traffic. Some firewalls block at an application level and further block connections even if TCP 443 is allowed.
4. Check the firewall at your site to ensure it is not filtering VPN.
5. Once the VPN is allowed to connect and you get the correct output from ifconfig tun0, rerun the host add script by using a slightly different command:

   /opt/qradar/bin/setup_qradar_host.py mh_setup interactive –r