hfctpl
August 19th, 2008, 11:26 AM
I am currently working with a company that is using ip's of 206.92.35.1 -.254.
In about a month we will be changing the ip scheme to 192.168.1.*. How many ip's will i be able to use by using 192.168.1.*? I am currently using about 200 ip's for pc's and other network equipement and I want to make sure that I have enough available ip's for future growth.
Train
August 19th, 2008, 11:55 AM
Each range from 0 to 255 can be represented by 8 bits, and is therefore called an octet.So you can still use the .1 - 254.
hfctpl
August 19th, 2008, 12:50 PM
Let me reword that.
I know I can use 192.168.1 - .254. But I'm nearing 220 devices right now - and I want more than 254 ip's.
puterfixer
August 20th, 2008, 01:24 AM
192.168.x.x being a private network IP class, you can have as many as 256*256 IP addresses, depending on how you want to "group" them in a subnet. Computers in the same subnet can communicate with one another, but not with other PCs in another subnet even if they share the physical infrastructure. You set the range of your subnet by adjusting the netmask.
The netmask 255.255.255.0 would divide the IP space in 256 subnets with 256 IPs each: 192.168.1.x is one subnet, 192.168.2.x is another one.
The netmask 255.255.254.0 creates 128 subnets with 512 IPs each (192.168.0.0 to 192.168.1.255, 192.168.2.0 to 192.168.3.255, etc.).
The netmask 255.255.252.0 breaks the same IP space in 64 subnets with 1024 IPs each (192.168.0.0-192.168.3.255, 192.168.4.0-192.168.7-255 etc.).
Same way you can use the netmask 255.255.255.192 to limit a subnet to only 64 IP addresses.
It's all basic IP subnetting, should you research this more :) The netmask defines how much of the IP address expressed in binary represents the address of the entire subnet, and what part is reserved for identifying individual hosts in that subnet. An online "subnet calculator" might help you understand better by playing with numbers, although it's clearer if you understand the binary part.
Now, considering that you'll have a network of private IP addresses, they will all be able to communicate with one another in the local network. But these IPs are not routable, meaning they are not directly accessible from the Internet. You will need a router to bridge the local network with the connection from your Internet Service Provider. Make sure that the router you'll be using allows you to extend the subnet to more than 255 IPs (basically allows you to change the netmask). Go through manuals and FAQs online before buying anything; what's on the box is usually a theoretical limit for SOHO equipment. "Share Internet connection with up to 255 PCs" means the built-in DHCP server is able to allocate up to 255 IPs to local network computers, but it will go belly up if more than 32 PCs will attempt to access the Internet at the same time.
Oh, and in any subnet, you always have 2 "unusable" IPs: first IP in range (.0) is considered the address of the entire network, and the last IP in range (.255) is the broadcast address. You shouldn't allocate any of these IPs to any equipment. Take one more IP which is usually assigned to the router or gateway, and that leaves you with 252 usable IPs in a C-class subnet.