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Servers – Ensure Packet Redirect Sending is Disabled

Secure Configuration Checks > Server

This check ensures that packet redirect sending is disabled on the server.

Disabling ICMP redirects prevents malicious actors from manipulating routing paths and enhances overall network security.

Check Details

  • Resource: Server
  • Check: Ensure packet redirect sending is disabled
  • Risk: Enabled packet redirects can allow attackers to manipulate routing paths and redirect traffic to malicious systems.

Remediation Steps

  1. Open a terminal session with root or sudo privileges.

  2. Verify current configuration:

    sysctl net.ipv4.conf.all.send_redirects
sysctl net.ipv4.conf.default.send_redirects
  3. Ensure both values are set to 0.

  4. Edit the sysctl configuration file:

    sudo nano /etc/sysctl.conf

  5. Add or update the following lines:

    net.ipv4.conf.all.send_redirects = 0
net.ipv4.conf.default.send_redirects = 0

  6. Apply the configuration changes immediately:

    sudo sysctl -w net.ipv4.conf.all.send_redirects=0
sudo sysctl -w net.ipv4.conf.default.send_redirects=0
sudo sysctl -w net.ipv4.route.flush=1

  7. Reload sysctl configuration:

    sudo sysctl -p
  8. Re-run the audit commands to confirm the configuration.
  9. Perform periodic audits to ensure compliance is maintained.

Updated on 06 March, 2026