In this article, we will explore some best practices and design considerations for enterprise switching, including VLANs, redundancy, and security measures.

VLANs

Virtual Local Area Networks (VLANs) are a powerful tool that can be used to segment network traffic and improve network performance. By creating separate VLANs for different types of traffic, such as voice or video, you can reduce congestion and ensure that each type of traffic receives the appropriate level of service.

When designing VLANs, it is essential to consider the number of devices on the network, the type of traffic, and the network topology. By carefully planning VLAN placement and configuration, you can avoid common mistakes such as overloading switches or creating VLANs that are too large.

Redundancy

In any enterprise network, redundancy is critical to ensuring that the network remains operational in the event of a failure. By using redundant links and switches, you can create a resilient network that can survive hardware failures or other disruptions.

When designing a redundant network, it is important to consider the potential failure points and ensure that redundant links or switches are appropriately placed to prevent single points of failure. Additionally, it is important to test and validate the redundancy configuration regularly to ensure that it is functioning correctly.

Security Measures

Security is a critical consideration for any enterprise network. Switches can be configured to provide a variety of security measures, including access control lists (ACLs), port security, and VLAN assignment based on user authentication.

When designing security measures for your network, it is important to consider the level of security required for different types of traffic and users. By carefully configuring security measures, you can ensure that your network is protected from unauthorized access and potential threats.

Common Mistakes

Finally, it is important to consider some common mistakes that can occur when designing and configuring enterprise switching. These mistakes can include overloading switches, creating overly complex VLAN configurations, and failing to properly test and validate redundancy configurations.

To avoid these mistakes, it is important to carefully plan and document the network design, test configurations thoroughly, and ensure that all network components are properly configured and functioning correctly.

In conclusion, enterprise switching is a critical component of any modern business network. By following best practices and carefully considering design considerations such as VLANs, redundancy, and security measures, you can improve network performance and avoid common mistakes.

What is Subnetting?

Subnetting is the process of dividing a larger network into smaller networks or subnets. It is accomplished by borrowing bits from the host portion of an IP address and using them to create subnets. The subnet mask is used to determine the network and host portions of an IP address. The subnet mask is a 32-bit number that consists of a series of ones followed by a series of zeros. The ones represent the network portion of the address, and the zeros represent the host portion of the address.

Why Subnetting is Important?

Subnetting is essential for the following reasons:

Efficient use of IP addresses: Subnetting allows you to use IP addresses more efficiently by dividing a larger network into smaller networks. This way, you can allocate IP addresses only to devices that need them, and avoid wasting IP addresses.

Better network performance: Subnetting can improve network performance by reducing network congestion and improving network efficiency.

Improved security: Subnetting can enhance network security by isolating different segments of a network and restricting access to specific devices.

Subnetting Cheat Sheet

The following subnetting cheat sheet will help you understand the basics of subnetting:

Subnet Mask: A subnet mask is a 32-bit number that determines the network and host portions of an IP address.

Network Address: The network address is the first address in a subnet and is used to identify the network.

Broadcast Address: The broadcast address is the last address in a subnet and is used to send a message to all devices on the network.

IP Address Range: The IP address range is the set of IP addresses available for use in a subnet.

CIDR Notation: CIDR notation is a shorthand notation for representing subnet masks. It is written as a slash (/) followed by the number of bits in the subnet mask.

Subnetting Formula: The subnetting formula is used to calculate the number of subnets and hosts per subnet. The formula is 2^n, where n is the number of bits borrowed for the subnet.

Subnetting Example: To subnet a network, follow these steps:

a. Choose the number of subnets required.
b. Choose the number of host bits required per subnet.
c. Calculate the subnet mask.
d. Calculate the network address and broadcast address.
e. Determine the IP address range.

Subnet Mask	CIDR Notation	Binary Value	Decimal Value
255.255.255.0	/24	11111111.11111111.11111111.00000000	255.255.255.0
255.255.255.128	/25	11111111.11111111.11111111.10000000	255.255.255.128
255.255.255.192	/26	11111111.11111111.11111111.11000000	255.255.255.192
255.255.255.224	/27	11111111.11111111.11111111.11100000	255.255.255.224
255.255.255.240	/28	11111111.11111111.11111111.11110000	255.255.255.240
255.255.255.248	/29	11111111.11111111.11111111.11111000	255.255.255.248
255.255.255.252	/30	11111111.11111111.11111111.11111100	255.255.255.252

Conclusion:

Subnetting is an essential concept in computer networking. It allows you to divide a larger network into smaller networks, use IP addresses more efficiently, improve network performance, and enhance network security. The subnetting cheat sheet provided in this article will help you understand the basics of subnetting and become a subnetting pro. Remember to use the subnetting formula and follow the subnetting example to subnet a network successfully.

Example 1: Subnetting a Class A Network

Let’s say we want to subnet the Class A network 10.0.0.0/8 to create smaller subnets for different departments in our organization. We want to create 4 subnets with a maximum of 2,000 hosts per subnet.

To create 4 subnets, we need to borrow 2 bits from the host portion of the IP address. This leaves us with 14 bits for the host portion of the IP address, which gives us 16,384 IP addresses (2^14) per subnet.

To determine the subnet mask for each subnet, we need to determine the value of the bits we borrowed. In this case, we borrowed the first 2 bits, which gives us a value of 192 (11000000) in binary. Therefore, the subnet mask for each subnet will be 255.255.192.0.

The table below shows the network address, subnet mask, and valid host range for each subnet:

In this example, we created 4 subnets, each with a subnet mask of 255.255.192.0. This means that each subnet has 16,384 IP addresses available for hosts.

Example 2: Subnetting a Class B Network

As previously mentioned, we have been assigned the IP address 172.16.0.0/16, which means we have 65,536 IP addresses (2^16) available for our network. However, we want to divide this network into smaller subnets.

To subnet this network, we need to borrow bits from the host portion of the IP address. Let’s say we decide to borrow 4 bits to create 16 subnets (2^4). This leaves us with 12 bits for the host portion of the IP address, which gives us 4,096 IP addresses (2^12) per subnet.

To determine the subnet mask for each subnet, we need to determine the value of the bits we borrowed. In this case, we borrowed the first 4 bits, which gives us a value of 240 (11110000) in binary. Therefore, the subnet mask for each subnet will be 255.255.240.0.

The table below shows the network address, subnet mask, and valid host range for each subnet:

In this example, we created 8 subnets, each with a subnet mask of 255.255.248.0. This means that each subnet has 8,192 IP addresses available for hosts.

Example 3: Subnetting a Class C Network

A Class C network has an IP address range of 192.0.0.0 to 223.255.255.0. Let’s say we have been assigned the IP address 192.168.0.0/24 and we want to subnet it. This means we have 256 IP addresses (2^8) available for our network. However, we want to divide this network into smaller subnets.

To subnet this network, we need to borrow bits from the host portion of the IP address. In this case, we will borrow 3 bits to create 8 subnets (2^3). This leaves us with 5 bits for the host portion of the IP address, which gives us 32 IP addresses (2^5) per subnet.

To determine the subnet mask for each subnet, we need to determine the value of the bits we borrowed. In this case, we borrowed the first 3 bits, which gives us a value of 224 (11100000) in binary. Therefore, the subnet mask for each subnet will be 255.255.255.224.

The table below shows the network address, subnet mask, and valid host range for each subnet:

Conclusion

Subnetting can seem daunting at first, but it is an important tool for managing IP addresses and optimizing network performance. By dividing a larger network into smaller subnets, we can reduce broadcast traffic and improve network security. The examples above demonstrate how subnetting works and how to determine the subnet mask and valid host range for each subnet.

If you’re new to subnetting, it’s important to take the time to understand the basics before diving into more complex examples.

For additional resources and information on subnetting;

Subnetting Practice: https://www.subnettingpractice.com/
IP Subnet Calculator: https://www.calculator.net/ip-subnet-calculator.html

In this article, we will provide a step-by-step guide to help you understand IP subnetting.

Step 1: Determine the IP Address Class

The first step in subnetting is to determine the IP address class. IP addresses are divided into 5 classes: A, B, C, D, and E. Classes A, B, and C are commonly used for networking.

Class A networks have a default subnet mask of 255.0.0.0, Class B networks have a default subnet mask of 255.255.0.0, and Class C networks have a default subnet mask of 255.255.255.0.

Step 2: Determine the Number of Subnets Needed

The next step is to determine the number of subnets needed. This is based on the number of departments, locations, or other factors that require separate networks. To determine the number of subnets, you need to borrow bits from the host portion of the IP address.

For example, if you need 4 subnets, you need to borrow 2 bits (2^2 = 4) from the host portion of the IP address.

Step 3: Determine the Number of Hosts Needed per Subnet

The next step is to determine the number of hosts needed per subnet. This is based on the number of devices that need to be connected to the network in each subnet.

To determine the number of hosts per subnet, you need to subtract 2 from the total number of IP addresses in the subnet. The first IP address is used for the network address, and the last IP address is used for the broadcast address.

For example, if you need 100 hosts per subnet, you need to have a subnet that provides at least 102 IP addresses (100 + 2).

Step 4: Create the Subnet Mask

The subnet mask determines the range of IP addresses available for hosts in each subnet. To create the subnet mask, you need to determine the value of the bits you borrowed from the host portion of the IP address.

For example, if you borrowed 2 bits from the host portion of the IP address, you need to determine the binary value of those bits. In this case, the binary value would be 11 (2 bits).

The subnet mask for this example would be 255.255.255.192 (or /26 in CIDR notation). This subnet mask provides 64 IP addresses (2^6 = 64) per subnet.

Step 5: Determine the Valid Host Range

The valid host range is the range of IP addresses available for hosts in each subnet. To determine the valid host range, you need to subtract 2 from the total number of IP addresses in the subnet.

For example, if you have a subnet with a subnet mask of 255.255.255.192, the total number of IP addresses in the subnet is 64. Subtracting 2 gives you 62, which is the number of valid IP addresses in the subnet.

The first IP address in the subnet is used for the network address, and the last IP address is used for the broadcast address. Therefore, the valid host range for this example would be 192.168.1.1 – 192.168.1.62.

Conclusion

Subnetting is an important tool that allows you to optimize your network performance and improve security. By dividing a larger network into smaller subnets, you can reduce network congestion, increase efficiency, and create separate segments for different departments or functions within your organization.

Follow another step by step walkthrough here – https://www.expertnetworkconsultant.com/subnetting/step-by-step-guide-to-understanding-ip-subnetting/