Example 2: Classless Inter-Domain Routing (CIDR) (Super-netting)

Question:

IP                           : 172.16.0.130

Subnet Mask         : 255.255.255.128

Find Network ID?

Answer:

Subnet Mask is used to find Network & Host bit 

IP and Subnet Mask in Binary

For Network ID, Make Host as zero

Make Host as 0's

172.16.0.128 is Network ID