You are designing a subnet mask for the 172.26.0.0 network. You want 26 subnets with up to 1800 hosts on each subnet. What subnet mask should you use? - Quora
Network Management. Subnet Mask | by Yasemin Çeven | Medium
Solved The subnet mask for the 188.40.35.131/29 is 0 | Chegg.com
IP Subnetting - Part 2: Subnet Masks & Their Effect