My personal opinion, if you're using RFC1918 addresses for internal > networks, you should only use 255.255.255.0 netmasks everywhere, even > though it's a network for one machine only. Dealing with netmasks is a > PITA, and should be avoided unless there's a real reason to use it, > for instance with valid IPs. JohnStanley Writes: One of the reasons that I take the trouble in doing it is that it Isolates the different Subnets and the Applications that are are on it. Also to keep nosey clients from browsing them if you don't want them to. I take more of security issue in perspective than an ease of use. Using a SNB of 20 don't give you but 14 host per sn. 1,048,575 what a mess that would be. But the issue is containing them in VLAN configurations and that can well be worth the hassel in doing it. on a large WAN, /24 vlan segments are often too small. we use /20 slices of 10-net for VLAN's here. /all/ 10-net vlans are /20. we also use some 172.16-31 and 192.168 spaces, those are all /24