How would you like to learn how to subnet a Class A network in 8 simple steps? Or maybe you want to take the leap from subnetting Class B or C networks to Class A? No matter which way you slice it, learning how to subnet a Class A network can be done with the help of this guide.
Step 1: Understand the Basics
Subnetting is the process of dividing a network into smaller subnets, each with its own unique IP address range. This can be done for a variety of reasons, such as increasing security or improving performance. As networks grow and more devices are added, it becomes increasingly difficult to keep track of all the devices. By subnetting an existing network and using VLSM (Variable Length Subnet Masking), a network administrator can keep things organized and simple by assigning different ranges to different departments or areas on their network.
For example, one department may need 1-10 IP addresses while another needs 10-20; this makes assigning multiple IP addresses much easier than having one large block that has variable amounts of space allocated depending on what is needed at any given time.
Step 2: Figure Out Where To Put The Numbers
When you’re subnetting, you’re essentially dividing up a network into smaller pieces. So, the first step is to figure out where to put the numbers. To do this, you’ll need to know the following:
-The network address (this is usually given to you)
-The subnet mask (more on this later)
-The number of hosts per subnet (more on this later)
Once you have that information, you can start putting the numbers in place. For example, let’s say we have a network with the address 192.168.1.0 and we want to subnet it into four subnets. We would take our network address and set the 0 to 255. That gives us our base-2 subnet mask. We also need to know how many bits we will divide up for each of our networks. The number of bits are equivalent to the number of hosts per subnet; for example, if I needed 10 hosts per subnet, I would divide my 32-bit address by 4 giving me 6 host bits or 2^6 which equals 64 total possible combinations from 0-63. Therefore, I would set my host portion as follows:
192.168.1.* 255.* *
With those numbers in place, all that’s left is determining what goes in between them!
Step 3: Begin Allocating Addresses
Now that you have your subnets created, it’s time to start allocating addresses. The first step is to create a list of all the devices that will be on each subnet. This includes servers, workstations, printers, and any other devices that will need an IP address. Once you have your list, you can start assigning addresses. For example, if you want 192.168.10.0/24 for 10.1.1-254 and 192.168.20.0/24 for 20.1-254, then we would assign the following:
-PC #1 = 10 1 1
-PC #2 = 10 2 1
-Printer = 20 3 4 (This is just one example)
Step 4: Determine if You Have Enough Addresses
Now that you know what your network’s address and subnet mask are, you can determine if you have enough addresses for your needs. To do this, simply count the number of addresses in your network. Then divide by two (since each half is considered one subnet).
If you need to use all 254 possible IP addresses on your network, then:
254/2 = 127
You will need 2 different networks or 3 networks with 126 IPs per network (126/2=63) or 62 IPs per network (62/2=31). For example, you might want to separate the following networks into their own classful networks. 192.168.1.0 – 192.168.1.127; 192.168.2.0 – 192.168 .2.127; 192.168.3.0 – 192.168.3.127 . There are several options for how to set up your network so that it doesn’t exceed 254 usable IP addresses. You could assign multiple networks in blocks of 63 or 62 usable IPs, depending on how many blocks you need. Alternatively, you could assign just one block of 127 usable IPs and make sure none of those ip-addresses are used on other devices such as printers, tablets, or laptops within the same LAN segment as they would also be counted against the total number of allowed IPs.
Step 5: Fix Underutilized Networks
If you find that you have an underutilized network, there are a few things you can do to fix it. First, check to see if there are any unused addresses that can be reallocated. Second, see if you can increase the size of the subnets.
Finally, if all else fails, you may need to create a new subnet. Once you’ve done this, contact your ISP or server host and request they change your IP address range. Next, tell them about the changes you made so they don’t allocate an address outside of your new subnet. They’ll update their records and assign you a new IP address range. After that, just reboot your computer or restart the router for everything to take effect!
Step 6: Deal With Broadcast Domains
Broadcast domains are an important part of networking, and subnetting a Class A network can help keep your network organized and running smoothly. Here are eight simple steps to subnetting a Class A network:
- understand what broadcast domains are and why they’re important
- determine the size of your network and the number of subnets you need
- create a list of all the IP addresses in your network
- sort the IP addresses into subnets
- determine the network address and broadcast address for each subnet
- deal with any special cases, such as reserved addresses or networks with only one host
- configure your router and test your new network . Your new network should now be up and running. The other computers on your network will now be able to communicate more efficiently because their traffic will be kept on the correct subnet.
- Repeat these steps for any other networks that may need it.
Step 7: Finalize Your Decisions
Now that you’ve gone through all the steps, it’s time to finalize your decisions and create your subnets. Keep in mind the following:
-The number of hosts you need per subnet
-The address range for each subnet
-The broadcast address for each subnet
-The network address for each subnet
-The gateway address for each subnet (if applicable)
Once you have all this information, you can create your subnets using any number of methods, including CIDR notation or IPcalc.