VLAN CAPACITY TOOL
Plan VLAN count, IPv4 prefix, address capacity and growth headroom.
Set the engineering assumptions and design parameters.
Review calculated capacity, limits and design checks.
The planner combines users, additional devices per user and infrastructure endpoints, then applies the selected growth allowance. It divides that demand by the target hosts per VLAN and selects the smallest conventional IPv4 prefix that can contain the calculated demand per VLAN.
The result reports the required VLAN count, recommended prefix, usable addresses per VLAN, total capacity, utilization, remaining headroom and the proposed VLAN ID range. It does not allocate actual network addresses or replace an IP address management plan.
For an office, school or branch network, count wired clients, Wi-Fi clients, phones, printers, access points, cameras and management interfaces. Separate security or operational zones where required instead of placing every device in one large broadcast domain.
Base growth on the design horizon, hiring forecast, device replacement and planned IoT adoption. Before deployment, also reserve gateway and DHCP addresses, check switch and firewall scale, review broadcast behavior, and leave contiguous address space for future VLANs and route aggregation.
RFC 1918 defines the private IPv4 blocks commonly used inside enterprise networks. Select a non-overlapping block and coordinate it with VPN, cloud and partner routes.
RFC 4632 describes CIDR addressing and aggregation. RFC 3021 permits /31 prefixes specifically on point-to-point links; it is not the multi-access host model used by this planner.
There is no universal limit. Choose a target that balances broadcast scope, failure isolation, security policy, gateway capacity and operational simplicity; then validate it against measured traffic and platform limits.
Use a planning period and evidence such as hiring, device refresh and IoT rollout forecasts. A percentage is an initial model, not a fixed standard; revisit the plan when actual utilization or business assumptions change.
No. It estimates VLAN count, prefix size and capacity. Allocate non-overlapping CIDR blocks separately and preserve room for route summarization, future VLANs and any address-management policy.
No. RFC 3021 defines /31 use for point-to-point links. This planner selects conventional multi-access IPv4 subnets and reserves network and broadcast addresses.
No. It supports preliminary capacity planning. Final design must also verify DHCP reservations, gateway redundancy, security zones, broadcast behavior, hardware scale, route aggregation and site-specific standards.
ENGINEERING WORKFLOW
Plan addressing, VLAN capacity, packet size, uplinks, optics, access policy and DNS behavior as one LAN design sequence.
