What will happen if we expand the subnet mask from 255.255.255.0 to 255.255.240.0 on our SonicWALL router? Our current IP range is 10.0.0.1 - 10.0.0.254. I know the new mask will expand the network to 10.0.0.1 - 10.0.15.254. However, what will happen if we update the mask on the SonicWALL router first before updating all the devices? Will the computers be able to communicate with each other still? I know refreshing the DHCP pool will update all those clients to the new Subnet. However, most of the computers have static IP addresses and they have 255.255.255.0 set in their adapter's IPv4 settings.
Basically, I want to know if I should update the router first or all the devices to the new subnet first.