Sorry, I missed the edit.
It looks to me like the common options are set correctly. By "correctly" I mean that these should work. eBox can, of course, be correctly configured differently.
Are computers on your LAN assigned static IP addresses in the 192.168.198.1 - 192.168.198.254 range? If not, and if you want eBox to dynamically assign addresses to them, you'll have to define some portion (or all, if you wish) of the available address space (the "available range") as a DHCP range under "Ranges."
For example, the eBox I'm behind right now has an available range of 192.168.2.1 - 192.168.2.254. Under "Ranges" I have a range named "Workstations," and that range extends from 192.168.2.100 - 192.168.2.124, for 25 DHCP addresses. The DHCP service assigns dynamic addresses out of that range only.
Are you trying to ping out of eBox itself or from a machine on the LAN?