iptables-restore — Restore firewall rules

Linux / Network and Firewall / iptables-restore.html

Reads an iptables-save file and applies the whole rule set at once.

Basic Information

What is this command?

iptables-restore reads a rule set and replaces the tables with it.

By default it flushes existing rules, which can lock you out of a remote host.

What problems does it solve?

• Roll back to a backed-up policy.
• Deploy identical rules to many hosts.
• Apply rules automatically at boot.
• Recover rules removed by mistake.

Key features

Restore from file

Point it at a backup file to replace the rules.

• When to use: When a change broke something.
• What you get: The rules from the file take effect.
• Limitations: Current rules are lost, so remote work needs care.

Merge mode

With -n existing rules are kept and new ones are added.

• When to use: When adding only a few rules.
• What you get: Rules are layered on the existing policy.
• Limitations: Duplicate rules can accumulate.

Check before apply

Use -t to test syntax without applying.

• When to use: Before applying on a production host.
• What you get: Errors are reported without changing anything.
• Limitations: Correct syntax can still be a risky policy.

Installation and usage

Check whether it is installed

iptables-restore --version

sudo apt install iptables

Real-world examples

Restore backup

Re-apply a saved rule set.

sudo iptables-restore < /root/iptables.backup

Merge rules

Add rules without flushing.

sudo iptables-restore -n < /root/extra.rules

Syntax test

Validate syntax without applying.

sudo iptables-restore -t < /root/iptables.backup