Hello friends, I want to know what the major determinants in the choice of an IP address are since the class of any IP address automatically chooses the subnet mask.

http://en.wikipedia.org/wiki/Classle...Domain_Routing

Classless Inter-Domain Routing (CIDR) is a method for allocating IP addresses and routing Internet Protocol packets. The Internet Engineering Task Force introduced CIDR in 1993...

" since the class of any IP address automatically chooses the subnet mask"

Where did you get this statement from?

There is a relationship between subnet masks and network class (A, B, C), but it's not necessarily automatic.

The link below is an excellent introduction to subnetting.

Don't be fooled by the HTML 3.0 look. It's clearly written and thoroughly explained. When I first found it, it was at some dot-edu site; my guess is that the author retired and posted it unchanged at a new location.

http://www.ralphb.net/IPSubnet/index.html

See this section for network classes: http://www.ralphb.net/IPSubnet/ipaddr.html

Welcome to LQ!

Most qualified IP addresses which are socially (validly) usable or being currently used in the Internet interaction are given and determined by authorities. This is not a matter of personal choice but a legal privilege.


If you mean the Class C 192.168.xxx.xxx. which is commonly authorized for subnet (local ethernet apart from the Internet) yes you have the option to fix the netmask since it is for you to determine the local subnet. Usually routers "automatically" sets the netmask to 255.255.255.0 but certainly you have the right to fix another mask.

Reading the materials linked by 'FrankBell' above will enlighten you enough.

Hope that helps. Good luck.

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