Calculating sub netmask

what is different calculation for subnetmask 255.255.255.192, 255.255.255.254 etc?i have read your artical but not really understand.can u give more explanation for that?

Not sure what you mean by different caculation. I assume your talking about wild card masks which is the opposite of subnets. And are used in Access Lists or OSPF network statements I think Eigrp also cant remember. But the opposite of 255.255.255.192 would be 0.0.0.63. I may be way off here but i think thats what you need. I think of it this way 255 is the MAX number per octect. So if you need the opposite you take what ever number in that octect and subtract 255 so 255 - 255 = 0 so... 0.0.0. would make the first 3 octets(sp?) so the last number 192 - 255 = 63 makeing 0.0.0.63.

Hope that helps

so when we use sub net 255.255.255.192, what is the range of ip that can exist within this network?

so when we use sub net 255.255.255.192, what is the range of ip that can exist within this network?

--24 bits in the first 3 octets and the first 2 bits from the last octed from the left for the Networks and 6 bits in the last octet for the hosts. Figure the IP's.