What hardware can I put in my network to prevent DoS attacks occurring through a private VPN? [on hold]

Suppose I allow a friend to remotely connect to my web server through VPN. However, a DoS attack is occurring on my web server. My friend told me he is not the one doing the DoS attack. What can I add to my network to stop th… Continue reading What hardware can I put in my network to prevent DoS attacks occurring through a private VPN? [on hold]