Bobby Liu.
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Project case study

IPTables Toolkit

A Bash toolkit for learning, applying, backing up, and restoring Linux firewall rules.

Project brief

Built to practice Bash while developing a clearer understanding of networking and host defense.

Core improvements

  • Switches between deny-by-default and accept-by-default policies.
  • Includes rules for ping floods, SYN floods, malformed packets, and smurf attacks.
  • Supports emergency blocking, rule flushing, backups, and restores.

Policy controls

This Bash toolkit collects common iptables commands in one menu so I could practice scripting while learning networking and host-security concepts.

  • Apply a deny-by-default policy.
  • Apply an accept-by-default policy.

Defensive rules

The toolkit includes example rules for several common traffic patterns and network attacks.

  • Ping floods
  • TCP SYN floods
  • Malformed packets
  • Smurf attacks

Recovery controls

  • Block all incoming traffic.
  • Flush all current rules.
  • Back up the current iptables rules.
  • Restore rules from a backup file.

Project demos

Click an image to expand
Back up current rules
Restore rules from backup
Change the default policy
Flush all rules