Firewalls can potentially block connections over VPN, depending on the configuration and security policies set in place. Some firewalls may not recognize VPN traffic as legitimate and may block it as a result. However, most modern VPNs are designed to work with firewalls, and many VPN providers offer features that can help bypass firewall restrictions. It's important to ensure that your VPN is configured correctly and that your firewall settings are not inadvertently blocking your VPN connection. If you encounter issues, you may need to adjust your firewall settings or contact your VPN provider for assistance.