Subnetting

jzaagman

I have been struggling with subnetting and figuring out questions that ask which subnet a router belongs on. Troubleshooting stuff. Can direct me on where to master subnetting?

thanks

john[/code]

Webmaster

www.learntosubnet.com also try searching our forums on subnetting.

cheeblie

In order to determine a subnet mask of an IP you must first determine which IP address class it belongs to.

IP addresses in the range of 1 - 126 are considered class A. IP addresses in the range of 128 - 191 are considered class B. IP addresses in the range of 192 - 223 are considered class C.

Now, if you have a class A IP your subnet mask should be 255.0.0.0. The reason for this is because a class A IP address uses the first octet for the network address, and uses the last three octets for the node address.

If you have a class B IP your subnet mask should be 255.255.0.0. The reason for this is because a class B IP address uses the first two octets for the network address, and uses the last two octets for the node address.

If you have a class C IP your subnet mask should be 255.255.255.0. The reason for this is because a class C IP address uses the first three octets for the network address, and uses the last octet for the node address.

Just remember that these values are default subnet masks and can be different as long as the values don't exceed 255. The important thing to understand is how many octets the mask takes up. I hope I was able to explain it well.[/b]

bellboy

jzaagman wrote:

I have been struggling with subnetting and figuring out questions that ask which subnet a router belongs on

surely a router will have an entity on all subnets where it is used at default gateway?