<p>We want to ensure that everyone using our VPN experiences a reliable and stable service. Through the years we have implemented changes to ensure that even if our API fails we can still continue to provide a VPN that can be relied upon.</p> <p>This was a way of resolving <a href="https://mullvad.net/blog/2021/1/20/no-pii-or-privacy-leaks-found-cure53s-infrastructure-audit/">MUL-03-002 WP2 from our Infrastructure Audit</a> in 2020.</p> <p>For our OpenVPN relays we have implemented Fail2ban to block non-authorized or malicious attempts at gaining account time.</p> <p>Fail2ban works by reading from a frequently wiped list of malicious unauthorized IP addresses in RAM (tmpfs). Regular paying customers and successful connections are not included in this, it is only to prevent any bruteforce attempts.