Network Zones

When creating the network zone (i usually let comodo do this automatically by default), what is the best option to choose from (See attached screen)

The range of ip addresses is as specified on my router’s set up page, but is this less secure than just letting comodo add zones the default way?

PS The ip address mask greyed out on the screen is the default setting from when comodo automatically detected my network.

[attachment deleted by admin]