Linux has several firewall options, including iptables, nftables, and firewalld, which can be used to filter and control network traffic.

Iptables is a CLI utility that is used to filter and block network traffic based on predefined rules.

Nftables is a newer firewall tool that replaces iptables and provides more flexibility and functionality.

Firewalld is a dynamic firewall management tool that provides a more user-friendly interface for configuring the firewall.

The Linux firewall should be configured to block all incoming traffic by default, except for traffic that is explicitly allowed.

Rules can be created based on source and destination IP addresses, ports, and protocols.

Firewalls can be configured to allow or block specific types of traffic, such as HTTP, SSH, or FTP.

Firewall configurations should be tested thoroughly to ensure that the rules are working as expected.