Calculate cidr and Number of Subnets

http://doc.m0n0.ch/quickstartpc/intro-CIDR.html

http://www.oav.net/mirrors/cidr.html

http://www.aelius.com/njh/subnet_sheet.html <==IMP

1)
* For cidr:/29 -- we can create 32 Subnets -- 6 Hosts per Subnet
* So, you can create 32 subnets with cidr:/19 like
   - 12.12.12.0/29
   - 12.12.12.8/29
   - 12.12.12.16/29
   - 12.12.12.24/29
     .......
     .......

   - 12.12.12.240/29
   - 12.12.12.248/29

* That is increment by 8 to create new subnets.

*  8 is IP range and we can calculate it from position of first 1 from the right, like.

* cidr:/29 means 29 1s, that is
                                                           8421
11111111 11111111 11111111 11111000

2)
* For cidr:/28 -- we can create 16 Subnets -- 14 Hosts per Subnet
* cidr:/28 means 28 1s, that is
                                                        168421
11111111 11111111 11111111 11110000

* Increment by 16 to create new subnets like.
   - 12.12.12.0/28
   - 12.12.12.16/28
   - 12.12.12.32/28