Technical Tip: How to prevent default DoS redirection page from displaying when a DoS policy is enabled

dkochhar · ‎09-07-2023

Description

This article describes how to prevent the default DoS redirection page from getting displayed to users when a DoS policy is enabled.

Scope

FortiGate.

Solution

From the FortiGate GUI:

Remove the HTML <body> section of the 'Network Quarantine DOS Block' replacement message by following the steps below:

In the FortiGate GUI, navigate to System -> Replacement Messages -> Extended view.

Select to edit the 'Network Quarantine DOS Block Page'.

In text/HTML format, select the body part and delete it. Afterwards, save the configuration.

After deleting the body portion from the HTML message, a white blank page is displayed.

To revert this change if there is a need to enable the DOS redirect page, follow the steps below:

In the GUI, navigate to System -> Replacement Message -> Extended view -> select to edit 'Network Quarantine DOS Block page' -> select 'Restore Defaults'.

From the FortiGate CLI:

To remove the DoS redirect page, run the following commands:

config sys replacemsg nac-quar nac-quar-dos

set buffer " "

end

To restore the DOS redirect page, run the following commands:

config sys replacemsg nac-quar nac-quar-dos

unset buffer

end