DomainBlocker Tool is a Bash-based automation tool for Linux firewall management that blocks or unblocks domain access using iptables and ip6tables. The tool accepts domain names as input, resolves them to their corresponding IP addresses, and automatically applies firewall rules to control traffic. The script supports both IPv4 and IPv6 protocols and allows users to specify traffic direction for blocking (incoming, outgoing, or both). It maintains a persistent database file (blocked_rules.db) that stores all configured blocking rules and tracks domain-to-IP mappings. DomainBlocker includes automatic IP resolution capabilities to handle DNS changes and can be configured for scheduled updates via cron jobs. The tool provides an interactive terminal menu for user interaction and requires root access to modify firewall rules. The script is designed for Linux-based systems, including Debian, Ubuntu, and Kali distributions. It depends on standard Linux utilities including iptables, ip6tables, dig (from dnsutils package), and cron for scheduled tasks. The tool is distributed under the MIT license and available as open source on GitHub.