How to use the vlan planner
- Add each department with its host count requirement.
- Provide a base supernet, e.g. 10.0.0.0/16.
- The tool allocates non-overlapping subnets and assigns VLAN IDs starting at 10.
VLAN Planner
Allocate subnets to VLANs based on department host counts.
Frequently asked questions
How many VLANs can a typical switch support?
Modern enterprise switches support 4,094 active VLAN IDs (the full 12-bit space minus 0 and 4095). Most deployments use far fewer—keeping spanning tree from becoming a management nightmare.
Which VLAN IDs are reserved or unsafe to use?
VLAN 1 is the Cisco default — many vendors recommend not using it for production traffic. VLAN 1002 to 1005 are reserved for Token Ring / FDDI legacy.
How do I size a subnet for 200 hosts per VLAN?
200 hosts plus growth and overhead pushes you past the /25 boundary (126 usable) — use /24 (254 usable) per VLAN to avoid re-sizing later.
Should management traffic have its own VLAN?
Yes. Separating management (SSH, SNMP, syslog) onto its own VLAN reduces blast radius if production data is compromised, and simplifies ACLs on the management plane.