when I configure custom option 6 on DHCP, will it be over rides the primary and secondary DNS?

[iarobertson]

Hello @ManojGuttikonda - I assume you're talking about a situation where you have DHCP issuing an address to the NGFW with the NGFW as a DHCP client, but you have statically defined the DNS entries on the NGFW.  You want to know whether using DHCP Option 6, which defines DNS servers for clients, will override those settings.

While I haven't tested this, to the best of my knowledge, the static configuration will override that issued by DHCP.