Are you ready to design your own enterprise network? In Part 2 of this series, we will dive deeper into the main office design. Let’s get started!
Contents
Planning the Network
To begin, we need to create a list of VLANs and subnets that will support our devices. We know that we have five servers, 125 workstations, and 125 phones. Each user has a workstation and a phone. However, we haven’t been informed about the number of printers or Wi-Fi devices.
Adding Printers and Wi-Fi
In a real-world scenario, we would gather more information from the customer about their needs. For now, let’s assume there are five printers, which we will include in the workstations network, bringing the host count to 130. As for Wi-Fi, we will assume that it is not required at the moment, but we will plan for its addition in the future. Let’s assume that each staff member has a phone or tablet that connects to Wi-Fi, along with a possible 150 wireless devices.
Assigning Subnets
To start assigning subnets, we will assign the 172.16.0.0/16 network to the main office. This may seem unconventional since it is one large network. However, breaking it down into smaller subnets has its advantages. By beginning all subnets in the main office with 172.16, we can easily troubleshoot issues and keep routing tables simple.
We need to plan for four networks in total, assigning a /24 network to each of them. These networks are all part of the larger 172.16.0.0/16 network. Using /24 networks offers simplicity and allows for up to 254 hosts per network, leaving room for growth and potential additional devices.
Breaking it Down
Breaking the network into smaller subnets instead of having one large subnet for the entire site has its benefits. It improves management by allowing us to easily identify devices based on their IP addresses. We can apply different settings to each subnet and prioritize voice traffic, such as phones, by placing them on a separate VLAN.
Additionally, breaking down the network into smaller subnets allows for better security control between subnets using ACLs or firewalls. Planning well now positions us to add these features in the future easily.
VLAN IDs and IP Assignments
To keep things simple, we can assign VLAN IDs that match the subnets. In this case, we will use VLAN IDs 5, 10, 15, and 20, which correspond to subnets 5, 10, 15, and 20, respectively. This makes it easier to remember and manage.
We can now start assigning IP addresses to the devices in the main office. The core switch will serve as the default gateway for each network, and we can choose any IP address within the subnet for this. Consistency is crucial, so using .1 as the default gateway in each subnet will make it easier to remember without referring to documentation.
For the servers, we can assign any IP addresses within the subnet. Let’s use .10 to .14. However, for the workstations and phones, configuring static IP addresses would be challenging. Instead, we will use a DHCP server to assign IP addresses dynamically.
DHCP Helper and Broadcast Messages
Since routers and layer 3 switches do not forward broadcast packets, we need a solution for DHCP requests from workstations and phones on different subnets. Here, we configure the core switch as a DHCP helper, also known as a DHCP relay. This allows the DHCP requests to reach the real DHCP server.
When a client sends a DHCP discover message, the core switch will forward it to the DHCP server. The server sends its offer message to the switch, which then forwards it back to the client. By configuring a DHCP helper, we don’t need a DHCP server in each subnet.
Conclusion
In this article, we explored the design aspects of the main office network. We learned about subnetting, VLAN IDs, and IP assignments to various devices. By breaking down the network into smaller subnets, we can improve management, apply different settings, and enhance security.
Stay tuned for Part 3, where we will continue discussing network design and explore other essential aspects. For more technology insights and articles, visit Techal.
FAQs
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Q: Why is breaking the network into smaller subnets important?
A: Breaking down the network into smaller subnets improves management, allows for better identification of devices, and enables the application of different settings and security controls. -
Q: What is the purpose of using VLAN IDs that match the subnets?
A: Using VLAN IDs that match the subnets simplifies management and makes it easier to remember the relationship between VLANs and subnets. -
Q: How can DHCP requests reach the server when they are on different subnets?
A: By configuring the core switch as a DHCP helper or DHCP relay, the switch forwards DHCP requests to the server and relays the server’s response back to the clients.
Conclusion
In this article, we explored the design aspects of the main office network. We learned about subnetting, VLAN IDs, and IP assignments to various devices. By breaking down the network into smaller subnets, we can improve management, apply different settings, and enhance security.
Stay tuned for Part 3, where we will continue discussing network design and explore other essential aspects. For more technology insights and articles, visit Techal.
