Subnet mask

in CCNA & CCENT
Hi,
I'm still really confuse with the subnet mask
What I don't understand is why some Network admin use the 3rd byte from the subnet instead of 2nd byte (look at the 24
it should be at the 2nd byte or?
eg:
62.161.99.115
255.255.248.0
Thanks for your help
I'm still really confuse with the subnet mask
What I don't understand is why some Network admin use the 3rd byte from the subnet instead of 2nd byte (look at the 24

eg:
62.161.99.115
255.255.248.0
Thanks for your help
Comments
Why dont you read a book?This forum is full of info regarding subneting.
The mask is important when deciding how many hosts you want to support on your network.
By the way the 2nd byte is used as well. That is a Class A address with 13 bits borrowed from the host portion, allowing for 8190 subnets with 2046 hosts each. That's the purpose of subnetting, a better use of address space and improve future scalability.