Spectre & Meltdown

In Flowmon version 12.5.0 and later, there is a new feature for stopping Spectre & Meltdown protection, so that overall performance may be improved (if needed). Stopping this protection makes the appliance vulnerable to Spectre & Meltdown exploits and must be evaluated on a case-by-case basis as a tradeoff between protection and performance. The feature should never be used without prior consultation with Flowmon Support at the Flowmon Support and Learning Hub.

Starting the feature means disabling the protection and vice versa.

The feature is stopped by default (meaning that the Spectre & Meltdown protection is active).

The full list of controls is as follows:

• Start (a reboot required for the change to take effect):

  • sudo /usr/sbin/spec-melt-vulnerability.sh start

  • sudo shutdown --reboot now

• Stop (a reboot is required for the change to take effect):

  • sudo /usr/sbin/spec-melt-vulnerability.sh stop

  • sudo shutdown --reboot now

• Is-started (check the current configuration, which will apply after a reboot):

  • sudo /usr/sbin/spec-melt-vulnerability.sh is-started

    • Returns 1 if Spectre & Meltdown protection will be applied after a reboot
    • Returns 0 if Spectre & Meltdown protection will be removed after a reboot

• Protection-status (check the currently-applied configuration):

  • sudo /usr/sbin/spec-melt-vulnerability.sh protection-status

    • Returns 1 if Spectre & Meltdown protection is active
    • Returns 0 if Spectre & Meltdown protection is disabled