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Servers – Ensure Bogus ICMP Responses are Ignored

Support > Fixing Checks > Server

06 March, 2026

This check ensures that bogus ICMP error responses are ignored by the system.

Ignoring invalid ICMP responses prevents unnecessary logging and protects the system from log flooding caused by misconfigured devices or malicious traffic.

Check Details

  • Resource: Server
  • Check: Ensure Bogus ICMP Responses are ignored.
  • Risk: Logging bogus ICMP responses can fill up log files, leading to resource exhaustion and potential denial of service.

Remediation Steps

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

  2. Verify current configuration:

    sysctl net.ipv4.icmp_ignore_bogus_error_responses
  3. Ensure the output is set to 1.

  4. Check persistent configuration:

    grep "net.ipv4.icmp_ignore_bogus_error_responses" /etc/sysctl.conf /etc/sysctl.d/*

  5. If not set, edit the sysctl configuration file:

    sudo nano /etc/sysctl.conf

  6. Add or update the following line:

    net.ipv4.icmp_ignore_bogus_error_responses = 1

  7. Apply the configuration:

    sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1

  8. Flush routing table to apply changes:

    sudo sysctl -w net.ipv4.route.flush=1
  9. Re-run the audit commands to confirm configuration.
  10. Perform regular audits to ensure compliance.