10.10.100.1 to 10.10.200.254

when in addresses or dhcp will it be something like:
10.10.100.0/16
mask
10.10.250.255

?

thanks,

That's not a valid IP network. You should read up on TCP/IP subnetting.

How many IP addresses do you need to support? What do you want the router IP address to be? Plug that information into a subnet calculator such as this one: http://www.subnetmask.info/

yeah there was a mistake writing the mask

but i need my system to give out ip to users:

start 10.10.100.1
stop 10.10.200.254

if mask is 255.255.255.0 that means 255 ip /24
if mask is 255.255.0.0 that means 255x255 ip /16
if mask is 255.0.0.0 that means 255x255x255 ip /8

knowing these i only need 100x255 ips
but i need it to be no less no more no out of this range
x.x.100.1 up to x.x.200.254

thanks

It doesn't break down like that.

The smallest possible network that contains 10.10.100.1 - 10.10.200.254 is 10.10.0.0/16. You can then of course set your IP pool to 10.10.100.1 - 10.10.200.254, but 10.10.0.1 - 10.10.99.254 and 10.10.201.0 - 10.10.255.254 will also be available though of course you don't have to use them.

Edit: changed "The only possible network that contains" to "The smallest possible network that contains".

It doesn't break down like that.

The only possible network that contains 10.10.100.1 - 10.10.200.254 is 10.10.0.0/16. You can then of course set your IP pool to 10.10.100.1 - 10.10.200.254

yeah, I like this approach and I'll just leave out what I don't need.

These IP's are used static to be assigned to users.

thanks a lot bro,