DMZ in HA active/passive Mode

Hi MMASLOUH

To meet requirements before HA can be configured.

• The dedicated HA link port must be a member of a zone with the type DMZ, and have a unique IP address on both devices.
• You must turn on SSH, on the DMZ/Custom zone, for both devices. 

You can use Custom Zone for HA : 

https://docs.sophos.com/nsg/sophos-firewall/18.5/Help/en-us/webhelp/onlinehelp/HighAvailablityStartupGuide/AboutHA/HAPrerequisitesStartupGuide/index.html 

Regards

Hello Bharat J,

Thank you.