How Many VLANs Are Supported on Cisco Catalyst 9300?

VLANs (Virtual Local Area Networks) are essential for logically segmenting Layer 2 networks in enterprise environments. With Cisco’s Catalyst 9300 series, a widely used access layer switch, it's important to understand how many VLANs it supports — both in theory and in practice.

This guide explains VLAN support on the C9300, how to configure VLANs, limitations, and best practices to follow.

VLAN Capacity on Cisco Catalyst 9300

Cisco Catalyst 9300 series switches are IEEE 802.1Q compliant, which means they can theoretically recognize up to 4094 VLANs (VLAN IDs range from 1 to 4094, with some reserved).

However, Cisco IOS XE software limits the number of active VLANs to 1000. This includes default VLANs, system VLANs, and any user-defined VLANs.

Configuration Example: Creating VLANs on C9300

Here’s how to configure a VLAN on a Catalyst 9300 switch using the CLI:

Switch# configure terminal
Switch(config)# vlan 20
Switch(config-vlan)# name VLAN20-Sales
Switch(config-vlan)# exit
Switch(config)# interface GigabitEthernet1/0/1
Switch(config-if)# switchport mode access
Switch(config-if)# switchport access vlan 20
Switch(config-if)# exit
Switch(config)# end
  

To verify:

Switch# show vlan brief
  

This command will display the list of VLANs currently active on the device.

Extended VLANs and VTP Mode

To use VLANs in the range of 1006–4094, ensure the switch is in VTP transparent mode:

Switch(config)# vtp mode transparent
  

If you're using VTP server or client modes, only VLANs 1–1005 are allowed.

Best Practices

• Limit unnecessary VLANs: Keep VLAN count optimized for performance and manageability.
• Use VTP wisely: In larger environments, VTP transparent mode offers more control and reduces the risk of unintended VLAN propagation.
• Monitor VLAN usage: Periodically check how many active VLANs are configured using show vlan or SNMP monitoring.
• Stack considerations: If your C9300s are in a stack, the VLAN count applies globally across the stack.

Frequently Asked Questions (FAQ)

Q1: Can I use all 4094 VLANs on a Cisco 9300?
A: No. Although 4094 VLAN IDs exist, only 1000 VLANs can be active at any one time.

Q2: Are VLANs in the 1006–4094 range supported?
A: Yes, but you must set the VTP mode to transparent to configure extended VLANs.

Q3: How can I check how many VLANs are active?
A: Use the command show vlan brief. It will list all active VLANs on the switch.

Q4: Does stacking multiple 9300 switches change the VLAN limit?
A: No. The 1000 VLAN limit applies per switch or switch stack.

Q5: Is there a way to increase the VLAN limit beyond 1000?
A: No. This is a platform and software-imposed limitation.

Related Articles

• How to Configure VLANs on Cisco Catalyst 9300
• How to Upgrade Cisco IOS XE