Help on IP addresses and subnet masking homework?

Im having trouble with my hw assignment, Im suppose to assign IP addresses using subnet mask technology to the following:





Network A is an Ethernet LAN with totally 400 computers


Network B is a WAN with totally 300,000 computers.





I read alot about masking subnet and IP addresses but I dont understand, can someone do the first problem for me so I can get an understanding of it. Thanks.Help on IP addresses and subnet masking homework?
With Network A you're going to use a subnet mask of /23, or 255.255.254. This will make available to the network 510 addresses. If you use 23 bits for the subnet mask, this leaves you with 9 bits for ip addresses, right? the last eight bits add up to 256. The last bit in the third octet will bring you up to 512. Subtracting two for the broadcast and network id, bringing you to 510 IP addresses. You can see this in binary form like this:


11111111.11111111.11111110.00000000


where the ones show you the subnet mask.Help on IP addresses and subnet masking homework?
I could answer this question, but since it's homework if someone does your homework. then you will pay for it when it's exam time.





This is the best website ever for subnetting. Go over it all and by the end you'll be an expert!!!





www.learntosubnet.com





but for this little one, i'll see what i can do for ya.





Network A = 400 computers.


On a class C subnet you can get a max of 256-2=254 hosts total.


So 255.255.255.0 = 254 hosts.


so 255.255.254.0 = 256 * 256 - 2 =65,534 hosts.


and so forth.





the octet ranges go in this order.


0,128,192,224,240,248,252,254,255.





each step allows 256-2 hosts (2 = ID and broadcast) = 254





so from what i started above...


255.255.255.0 = 254 (Class C)


255.255.254.0 = 65,534 (Class B)


255.255.252.0 = (256*256*256) - 2 = 1703934 hosts....and so on.





Do that whole webpage and you'll be better than your teacher in the end!!





Good luck





By the way, its been years since i done this stuff, so i too am a little rusty.
Here are some sites to learn and practice subnetting:





http://easysubnet.com/


http://subnettingquestions.com/custom/br鈥?/a>