Mike, Just for your information, there is also a third lesser known range 172.[16-31].x.y Each of the three ranges are available for private use, and are illegal on the Internet. Which you use is completely up to you and is generally based upon your own individual needs. If you take the first part of any address, and represent it in binary, it will tell you the address "class". 0.... -> Class A address 10... -> Class B address 110.. -> Class C address 1110. -> Class D address 11110 -> Class E address 10 -> 0000 1010 -> Class A - Default mask is 255.0.0.0 - CIDR /8 172 -> 1010 1100 -> Class B - Default mask is 255.255.0.0 - CIDR /16 192 -> 1100 0000 -> Class C - Default mask is 255.255.255.0 - CIDR /24 Class D was reserved for multi-cast addresses. Most of these you will see in the 224.x.y.z range 224 -> 1110 0000 -> Class D - Default mask is 255.255.255.255 - CIDR /32 Class E was reserved, but never used, and never will be now that IPv6 is here. Using a class A address reserves 8 bits for the network address (i.e. 10) and 24 bits for the hosts, which leaves you with 2^24 or 16,777,216 hosts - 2 (network broadcast, and network addresses) Using a class B address reserves 16 bits for the network (i.e. 172.16) and 16 bits for the hosts, which leaves you with 2^16 or 8,65,536 hosts - 2 (network broadcast, and network address) Using a class C address reserves 24 bits for the network (i.e. 192.168.1) and 8 bits for the host, which leaves you with 2^8 or 256 - the same 2 addresses. Your broadcast address is where all bits in the host part are 1, and your network address is where all host bits are 0. I hope this helps you understand the difference between addresses, and helps you pick the right one for your needs. Kevin Fries On Thu, 2012-03-08 at 10:18 -0700, Michael Havens wrote: > What is the difference between the 192.168.x.y and the 10.x.y.z range? > They are both the private network ranges but why would one decide to > use one but not the other? > > -- > :-)~MIKE~(-: > --------------------------------------------------- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss --------------------------------------------------- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss