Computer networks have become an integral part of businesses and organizations, enabling them to interconnect remote workstations, computers, and servers. The internet has also transformed the way organizations operate, and connectivity has become vital for remote collaboration, data sharing, and process automation. However, managing a network can become complicated as it grows, becomes harder to diagnose, and starts to consume more resources. IP subnetting has emerged as a powerful strategy to make networks more manageable, scalable, and efficient.
Private IP address space
Businesses today often use private IP address space to manage their internal devices. These private IP addresses are not visible to the internet and are reserved for private networks. The most common IP addresses for private networks are from Class A, B, and C, each with their own specific ranges and sub-ranges. When a device with a private IP address needs to communicate with the internet, the traffic is routed through a Network Address Translation (NAT) device that translates the source address to a public IP address.
The role of a default gateway in subnet communication
When a device within a subnet needs to communicate with other devices outside of its subnet, it uses a default gateway or router to route the traffic to the right destination. The default gateway has an IP address that is in the same subnet as the device, and it acts as a bridge between subnets. Routing tables in the default gateway map the network topology, allowing the router to make intelligent decisions about where to send the traffic.
The Impact of Broadcast Traffic on IP Subnets
In very large IP subnets, broadcast traffic can consume a significant amount of network throughput, slowing down or even halting other traffic. Broadcast traffic refers to any traffic that is sent to all devices within a subnet, regardless of the intended recipient. Examples of broadcast traffic include Address Resolution Protocol (ARP) requests, Dynamic Host Configuration Protocol (DHCP) broadcasts, and Network Discovery protocols. To mitigate the impact of broadcast traffic, administrators can use VLANs or create smaller subnets.
Understanding IP Address Space for Long-Term Network Planning
Before administrators start designing an IP address scheme that will last the lifespan of a production network, they must consider the types of IP address space required to accommodate existing hosts and potential growth. Since IPv4 addresses run out eventually, new devices that come online will require an IP address. IPv6 addresses are a more robust option and provide almost unlimited addresses. However, the adoption of IPv6 is still in its early stages, and many organizations still use IPv4.
IP subnet mask as a network address designator
An IP subnet mask is a 32-bit address that designates which portion of an IP address is the network address and which is part of the pool of individual endpoint addresses. The network portion of the IP address is reserved for network details such as routing, management, and other network utilities, while the rest of the address space can be allocated to hosts.
Determining the Right IP Subnet for Accommodating Hosts
To determine the correct IP subnet to accommodate hosts, network administrators must first determine the maximum number of devices on the subnet. For example, if an administrator wants to create an IP subnet that can support up to 254 hosts, they need to find out which IP subnet can meet this requirement. In this scenario, a subnet mask of 255.255.255.0 can be used, which assigns the first three octets to the IP network in total and the last octet to the individual host.
Creating Multiple IP Subnets for Large-Scale Networks
For large-scale networks, administrators can create multiple IP subnets to manage devices more efficiently. Doing so allows the creation of 254 unique IP subnets, each of which can accommodate up to 254 host addresses. Multiple subnets make it easier to organize devices based on their functions, departments, or geography, among other criteria.
Designing Sufficient IP Subnet Space for Expansion
Enterprises that plan to expand substantially within a LAN should design their networks to include plenty of IP subnet spaces. With adequate IP subnet space reserved for future expansion, administrators can add new devices without disrupting the existing network or having to reconfigure the IP addressing scheme.
Allocating IP subnet space for remote locations
Organizations that want to scale their networks beyond the corporate LAN can allocate IP subnet space for remote data centers, clouds, and remote work sites. When doing so, network administrators create independent IP subnets that are interconnected through VPNs or other connectivity solutions. For security reasons, they often use private IP addresses for remote networks, making it harder for unauthorized access or interception.
IP subnetting is a powerful strategy to manage networks more efficiently, improve scalability, and security while reducing operational costs. By subnetting large networks into smaller ones, network administrators can manage their devices better, avoid broadcast storms, and plan for future growth. While IP subnetting requires planning, it is a proven method for organizations to manage their networks and connect their devices with optimized performance, reliability, and security.