SSH Port Changer Script

Description

This Bash script is designed to change the SSH port in the sshd_config file, configure firewall rules, update SELinux policies (if enabled), and restart the SSH service to apply the changes.

Author

Magdi

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Features

• Allows changing the SSH port via command-line arguments.
• Creates a backup of the sshd_config file before modifying it.
• Updates firewall rules (supports firewalld and UFW).
• Configures SELinux policies if enforced.
• Restarts the SSH service after making changes.
• Displays the new SSH port for confirmation.

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Usage

Run the script with the following options:

./ssh_port_changer.sh [-p port_number] [-h]

Options:

• -p PORT : Specify the new SSH port (default is 9999).
• -h : Show the help message and exit.

Example Usage

To change the SSH port to 2222:

./ssh_port_changer.sh -p 2222

If no port is specified, it defaults to 9999:

./ssh_port_changer.sh

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Firewall Configuration

The script automatically updates the firewall:

• If firewalld is installed, it adds the new port and reloads the rules.
• If UFW is installed, it allows the new port and reloads the firewall.
• If no firewall is detected, a warning is displayed to configure it manually.

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SELinux Configuration

If SELinux is in Enforcing mode, the script updates SELinux policies to allow the new SSH port.

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Notes

• Run the script as root to modify system configurations.
• Ensure to update firewall rules before restarting SSH to avoid being locked out.
• After the script runs, verify the new SSH port with:

  sudo sshd -T | grep "port"

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Troubleshooting

• If SSH fails to restart, check logs using:

  sudo journalctl -xe

• If locked out after changing the port, use console access to revert changes.

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