To set the subnet mask you just log on to the sensor and use the command
set sensor ip <IP Address> <Subnet Mask>
You can just enter the existing IP address and the new subnet mask separated by a space if you only want to change the subnet.
You can't change it from the manager.
You don't need a central manager. If you have multiple regional managers the central manager just allows you to configure your policies etc. in one place.
Hey Peter thanks for your respond
We used to have IBM ISS SiteProtector (IDS system) it had a Proventia appliance
Through Proventia appliance within web browser we could change the network configs
Thats i would like to know is there any chance to not connect to Sensor and make changes remotely ?