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Servers – Ensure Absence of IPv6 Router Advertisements

Support > Fixing Checks > Server

06 March, 2026

This check ensures that IPv6 router advertisements are disabled on the server.

Accepting router advertisements can allow unauthorized systems to modify routing tables, potentially redirecting traffic to malicious destinations.

Check Details

  • Resource: Server
  • Check: Ensure IPv6 router advertisements are not accepted
  • Risk: Accepting router advertisements can allow attackers to manipulate routing paths and redirect network traffic.

Remediation Steps

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

  2. Set the active kernel parameters to disable IPv6 router advertisements:

    sudo sysctl -w net.ipv6.conf.all.accept_ra=0
sudo sysctl -w net.ipv6.conf.default.accept_ra=0
sudo sysctl -w net.ipv6.route.flush=1

  3. Ensure the configuration persists after reboot by editing sysctl configuration file:

    sudo nano /etc/sysctl.conf

  4. Add or update the following lines:

    net.ipv6.conf.all.accept_ra = 0
net.ipv6.conf.default.accept_ra = 0

  5. Apply the changes:

    sudo sysctl -p

  6. Verify the configuration:

    sysctl net.ipv6.conf.all.accept_ra
sysctl net.ipv6.conf.default.accept_ra
  7. Ensure both values are set to 0.