Global ConfigDomain 2.0

vlan

Initializes a logical Layer 2 broadcast domain inside the switch database and transitions the CLI session into dedicated VLAN configuration submode.

Quick Reference

Execution ModeSwitch(config)#

Submode PromptSwitch(config-vlan)#

Default VLAN StateVLAN 1 (Cannot be deleted)

Negation Commandno vlan [vlan-id]

Syntax & Parameters

vlan [vlan-id]

Parameter Description & Range Rules

[vlan-id]

Parameter	Description & Range Rules
[vlan-id]	The numerical tag assigned to the Broadcast Domain. 1 - 1001: Standard Range VLANs. Stored inside the flash memory file named `vlan.dat`. Fully modifiable. 1002 - 1005: Cisco Legacy Defaults (Token Ring, FDDI). Permanent values; cannot be modified or deleted. 1006 - 4094: Extended Range VLANs. Used for service provider topologies or massive multi-tenant datacenters. Saved directly to the running configuration payload, not the `vlan.dat` structure.

The numerical tag assigned to the Broadcast Domain.

1 - 1001: Standard Range VLANs. Stored inside the flash memory file named vlan.dat. Fully modifiable.

1002 - 1005: Cisco Legacy Defaults (Token Ring, FDDI). Permanent values; cannot be modified or deleted.

1006 - 4094: Extended Range VLANs. Used for service provider topologies or massive multi-tenant datacenters. Saved directly to the running configuration payload, not the vlan.dat structure.

CLI Deployment Scenarios

Scenario 1: Instantiating and Isolating a Broadcast Domain

You need to spin up a standalone network segment to keep client voice traffic separate from the raw server arrays.

Switch(config)# vlan 50

Switch(config-vlan)# ! Session context successfully pivots to submode

Scenario 2: Completely Wiping a VLAN

A database segment is decommissioned, and you need to erase the broadcast container from the local database framework.

Switch(config)# no vlan 50

! Any physical interface remaining in access mode under VLAN 50 becomes an inactive 'orphan interface' and drops traffic until re-assigned.

CCNA Exam Gotchas

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The Orphan Port Trap

If you execute no vlan 10 on a switch, Cisco IOS does not automatically move those access ports back to VLAN 1. The interfaces remain bound to a non-existent index. They will show an operational status of inactive, and all traffic passing through them will be black-holed.

[!]

VLAN 1 and 1002-1005 Constraints

Cisco will try to trick you with a multiple-choice question on deleting management constraints. You cannot rename, alter, delete, or filter out vlan 1 or the factory structural blocks 1002 - 1005. They are completely locked down inside the binary software logic.