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VLAN ID Range Calculator

Networking

Define a VLAN Range

Reserved VLAN Reference (IEEE 802.1Q & Cisco)

VLAN 1

Default/Native VLAN (Cisco)

VLAN 1002

FDDI Default (Cisco reserved)

VLAN 1003

Token Ring (Cisco reserved)

VLAN 1004

FDDI-Net (Cisco reserved)

VLAN 1005

Token-Ring-Net (Cisco reserved)

VLAN 4094

Vendor internal (often reserved)

About This Tool

🖧 VLAN ID Range Calculator – Plan & Allocate IEEE 802.1Q VLANs

The VLAN ID Range Calculator is a professional networking utility designed for engineers, administrators, and students who need to plan, allocate, and document Virtual LAN ID ranges across Layer 2 switch infrastructure. IEEE 802.1Q defines a 12-bit VLAN identifier — giving you IDs from 1 to 4094 — and this tool helps you divide that space into logical, non-overlapping blocks for departments, zones, tenants, or network segments.

What Are VLAN IDs?

A VLAN ID (Virtual LAN identifier) is a numeric tag embedded in Ethernet frames by IEEE 802.1Q-compliant switches to separate broadcast domains without requiring separate physical hardware. Each VLAN ID represents an isolated logical network segment. Modern enterprise switches support the full 802.1Q range of 1–4094, split into the normal range (1–1005, propagated via VTP) and the extended range (1006–4094, requiring VTP Transparent mode or VTP v3).

Reserved VLAN IDs to avoid
VLAN 1 is the default/native VLAN on Cisco switches. VLANs 1002–1005 are reserved for legacy FDDI and Token Ring. VLAN 4094 is often reserved by vendors for internal use. This tool automatically flags these IDs in your ranges.

How to Use This Tool

Enter a Start VLAN ID and an End VLAN ID to define a range, then optionally add a name and purpose label. Click Add Range to register the block. Repeat for each department, zone, or segment. The tool instantly:

  • Calculates the range size (total IDs) and usable count (excluding reserved IDs)
  • Identifies any reserved or special-purpose VLANs within the block
  • Detects conflicts between overlapping ranges and highlights them
  • Renders a color-coded allocation bar across the full 1–4094 space
  • Lists all free (unallocated) VLAN blocks remaining
  • Generates vendor-specific CLI configuration for Cisco IOS, NX-OS, Juniper JunOS, and Aruba/HP ProCurve

VLAN ID Space Reference

VLAN RangeClassificationNotes
1Default/NativeCisco default VLAN; avoid for user traffic
2–1001Normal RangeUsable VLANs propagated by VTP
1002–1005Cisco ReservedLegacy FDDI and Token Ring; cannot be deleted
1006–4093Extended RangeRequires VTP Transparent or VTP v3
4094Vendor ReservedOften used internally by vendor OS; check your hardware

Conflict Detection

When two VLAN ranges overlap, traffic misconfiguration or dropped frames can occur silently — making conflict detection critical in multi-team environments. The calculator checks every pair of ranges using the formula:

overlap = max(startA, startB) ≤ min(endA, endB)

Any overlapping ID set is flagged in the summary table with a Conflict badge and highlighted on the allocation bar, letting you resolve issues before pushing configuration to live switches.

Vendor Configuration Snippet Generator

Once your ranges are defined, switch to the Config Snippet tab, select your switch platform, and the tool outputs ready-to-paste CLI commands:

  • Cisco IOS — individual vlan <id> / name blocks per VLAN ID
  • Cisco NX-OS — condensed vlan <start>-<end> block syntax
  • Juniper JunOS — set vlans <name> vlan-id-range statements
  • Aruba/HP ProCurve — per-VLAN vlan <id> name commands

Copy the snippet with one click or download it as a .txt file for your change management records.

Extended vs. Normal VLAN Range

The normal VLAN range (1–1005) is the classic 802.1Q space supported by all switches and automatically propagated via VTP (VLAN Trunking Protocol) in server or client mode. The extended VLAN range (1006–4094) was introduced to support large-scale deployments (data centers, service providers, multi-tenant environments) but requires the switch to be in VTP Transparent mode or using VTP version 3, since extended VLANs are not carried in VTP advertisements by default.

VLAN Allocation Best Practices

  • Reserve blocks by function — e.g., 10–19 for management, 100–199 for user access, 200–249 for guest Wi-Fi, 300–399 for IoT, 500–519 for DMZ.
  • Avoid VLAN 1 for user traffic — attackers can exploit native VLAN misconfigurations (VLAN hopping) to escape isolation.
  • Leave gaps between allocations — padding between ranges allows future growth without renumbering existing segments.
  • Document allocations — export the CSV after planning to keep an auditable record of each VLAN block's owner, purpose, and creation date.
  • Use extended VLANs only when needed — if your VTP domain is in server mode, extended VLANs will not propagate; put edge switches into transparent mode first.
Tool scope and accuracy
This calculator implements IEEE 802.1Q VLAN ID rules and Cisco-specific reserved IDs. Some hardware vendors reserve additional VLANs beyond 4094 or impose platform-specific limits (e.g., maximum active VLANs per switch). Always validate against your hardware's datasheet before deploying.

Frequently Asked Questions

Is the VLAN ID Range Calculator free?

Yes, VLAN ID Range Calculator is totally free :)

Can I use the VLAN ID Range Calculator offline?

Yes, you can install the webapp as PWA.

Is it safe to use VLAN ID Range Calculator?

Yes, any data related to VLAN ID Range Calculator only stored in your browser (if storage required). You can simply clear browser cache to clear all the stored data. We do not store any data on server.

What is a VLAN ID and what range is valid?

A VLAN ID (Virtual LAN identifier) is a 12-bit numeric tag defined by IEEE 802.1Q that identifies a logical network segment on a switch. Valid VLAN IDs range from 1 to 4094. VLAN 0 and 4095 are reserved by the standard and cannot be assigned to user VLANs.

How does this VLAN ID Range Calculator work?

Enter a start and end VLAN ID to define a range, optionally give it a name, then click 'Add Range'. The tool calculates the range size, identifies any reserved IDs within the block (like VLAN 1, 1002–1005, and 4094), detects conflicts with other added ranges, and shows a visual allocation bar across the full 1–4094 ID space.

Which VLAN IDs are reserved or special-purpose?

VLAN 1 is the default/native VLAN on Cisco switches and should not be repurposed for user traffic. VLANs 1002–1005 are reserved by Cisco for legacy FDDI and Token Ring protocols. VLAN 4094 is often reserved for internal vendor use. VLANs 1006–4094 are the extended range and require VTP Transparent mode or VTP v3.

What is the difference between normal and extended VLAN range?

The normal VLAN range (1–1005) is supported by all 802.1Q-compliant switches and can be propagated via VTP. The extended VLAN range (1006–4094) requires VTP Transparent mode or VTP version 3, and is not supported on all older hardware. Most enterprise switches support the full 1–4094 range in modern firmware.

How does conflict detection work?

When you add multiple named VLAN ranges, the tool checks each pair for overlap. Two ranges [a,b] and [c,d] conflict if max(a,c) ≤ min(b,d). Conflicting ranges are highlighted in the summary table and on the allocation bar so you can quickly spot and resolve overlapping allocations.

Can I export the VLAN allocation table?

Yes. Use the 'Export CSV' button to download the full allocation table as a comma-separated file suitable for spreadsheets or documentation. You can also copy the vendor-specific configuration snippet (Cisco IOS, NX-OS, Juniper JunOS, or Aruba/HP) for direct use in switch CLIs.