Subnetting can improve network performance, security, and overall network administration. But what is it, and why does your organization need it?
Let’s find out.
What is Subnetting?
Subnetting is a straightforward concept. Put simply, it involves splitting a large network into smaller, more manageable segments called subnets.
When organizations logically partition an Internet Protocol (IP) network into multiple, smaller network segments, they can better manage and monitor it, improving its security, flexibility, and performance.
How Subnetting Works
Before we demonstrate how subnetting works, it’s best to orient yourself with the basic components.
A subnet contains three core elements:
- Network address (subnet ID): This is the first address of the subnet.
- Broadcast address: This is the last address of the subnet.
- Subnet mask: A bitmask that is used to identify the subnet of an IP address.
The subnetting process involves using a subnet mask to divide all the available IP addresses into smaller clusters called subnetworks. The subnet mask determines which portion of an IP address belongs to your network and which portion identifies the host within that same network.
To put it in a more easy-to-understand way:
- Network admins take all the IP addresses and decide how to split them.
- Each device gets a unique address that includes a network and host address.
- The subnet mask creates boundaries between each network and broadcast address.
How a Subnet Connects with IP and IP Addresses
Subnetting is closely related to IP addressing. Any device connected to a network needs a unique IP address for identification and communication. Additionally, each IP address consists of two parts, which are the host identifier and the network identifier.
If you’re subnetting your network, you’re essentially taking bits from the host portion of your IP address to create additional network identifiers. This process means you can more efficiently use your IP address space and better organize the devices within your network.
Benefits of Subnetting
Subnetting unlocks big network management and performance benefits. Let’s examine the main reasons why subnetting can help your organization.
More robust security
Subnets help isolate network segments. This makes security threats easier to contain, and your business can also implement access controls more efficiently.
Faster networks
Smaller broadcasting domains and less unneeded traffic help teams optimize network performance and prioritize essential services.
Improved network management
Managing multiple smaller subnets means network administration, troubleshooting, and maintenance is far simpler.
IP address utilization
Subnetting means that the allocation of IP addresses with your organization is more flexible and efficient.
Reduced network congestion
Finally, subnetting allows you to minimize network congestion because traffic is confined to particular subnets.
Why Subnetting Matters for Network Monitoring?
While subnetting offers the excellent benefits listed above, it also greatly enhances network monitoring. Here, we’ll examine why subnetting matters to this important process.
Granular visibility
Breaking down a network into smaller, more manageable subnets means visibility becomes more granular, making network monitoring easier in the following ways:
- If network problems occur, admins can quickly identify and isolate them, reducing the time it takes to troubleshoot and resolve them. Subnets also minimize the impact of problems across the entire network, meaning less downtime in the event of an issue.
- You can also assign subnets to particular departments or locations within your organization. Splitting your network into these segments allows you to monitor each area’s activity, performance, and resource needs.
- Finally, subnetting facilitates a hierarchical approach to network monitoring. Administrators can take a high-level overview before drilling down to individual or grouped subnets, allowing for a better understanding of network activity.
Better performance analysis
Subnetting can also positively impact network analysis and optimization.
Here’s how:
- When you monitor activity in and between subnets, you can gain valuable insights into data flow and identify bottlenecks or unusual patterns.
- Subnetting allows for more precise monitoring of resource usage within specific network segments, which helps to balance loads and allocate resources more effectively.
- Subnets also facilitate better bandwidth management, allowing administrators to implement and monitor QOS policies that ensure that critical apps and services get the resources they need.
Enhanced security
Subnetting also plays a key role in improving network security across your organization. Here are a few reasons why.
- Security tools can focus on particular subnets, making it easier to detect anomalies and potential security breaches within those segments.
- In the event of a security incident, subnetting allows for rapid isolation of affected areas, preventing threats from spreading to other parts of the network.
- You can also add different security and monitoring rules to individual subnets. This process allows you to have suitable and effective security protocols that reflect the needs of each segment or department.
Best Practices for Subnetting in Network Monitoring
Here are some subnetting best practices that you can implement to boost your network monitoring.
1) Plan Subnets Logically
You must take a logical approach to planning and defining subnets. Some of the best ways to split these groups include by different departments, geographical locations, or even by security requirements.
A well-planned subnet structure can significantly improve network performance and manageability. For example, when you separate subsets by floor or departments, you can reduce network congestion and improve overall performance.
2) Document Subnet Configurations
If you want to to manage your network effectively, detailed subnet scheme documentation is necessary.
Some of the areas that your documentation should contain include:
- IP address ranges.
- Subnet masks.
- VLAN assignments.
Add to this documentation as your network evolves and grows. If you have solid documentation, it simplifies troubleshooting, helps prevent IP address conflicts, and assists with capacity planning.
3) Use VLANs Where Applicable
You can implement Virtual LANs (VLANs) alongside your subsets to further segment your network and gain additional security benefits. VLANs help you create logical network segments (as described in best practice #1) that can cater to multiple physical locations. These processes provide serious flexibility in the design and management of your network.
Here are some tips for using VLANs with subnets:
- Assign each VLAN to a dedicated subnet.
- Isolate sensitive traffic with VLANs.
- Implement access control lists (ACLs) between VLANs for more robust security.
4) Leverage Monitoring Tools
If you want to unlock the full range of benefits outlined above, use network monitoring tools like Domotz that do subnet-aware analysis and reporting. Tools of this caliber offer deep insights into network performance security and allow you to:
- Identify performance bottlenecks.
- Detecting unusual traffic patterns.
- Monitor subnet utilization.
IP address management and detailed network performance reports are critical for identifying problems and ensuring you get the absolute most from your network.
Further reading:
- VLAN vs Subnet – Monitoring Networks With Subnets and VLANs
- How to Make a Network Topology Diagram
