What network security measures are in place (ex. firewall rules, etc.)?

The firewall solution we have currently deployed is ConfigServer Security & Firewall (CSF).  CSF is a firewall configuration tool that provides several benefits for server security.

Firewall protection:  

CSF provides a robust and flexible firewall configuration that allows users to filter incoming and outgoing traffic, block IP addresses, and configure other firewall rules to protect against attacks

Brute-force protection:  CSF includes built-in protection against brute-force attacks by monitoring login attempts and automatically blocking IP addresses that exceed a set threshold.

Security notifications:  CSF can be configured to send security notifications to the server administrator when certain events occur, such as failed login attempts, firewall blocks, or other security-related events.

Server hardening:  CSF includes several server hardening features that help to protect against common attack vectors, such as disabling unused services, hardening SSH configuration, and more.

IP reputation checking:  CSF can be configured to check the reputation of incoming IP addresses against various threat databases, helping to block known malicious actors.

DDoS Protection:  CSF includes several features that help to protect against DDoS attacks, such as connection tracking and rate limiting. This helps to ensure that the server remains available and responsive during periods of high traffic.

IPv6 Support:  CSF fully supports IPv6, allowing users to apply firewall rules to both IPv4 and IPv6 traffic. This helps to ensure that the server is fully protected against all types of network traffic.

Stateful Packet Inspection (SPI) firewall:  This is a login and intrusion detection mechanism, and a general security application for Linux.