Which VLANs exist by default on a Cisco switch?

The correct answer identifies the default VLANs that are present on Cisco switches. By default, every Cisco switch includes VLAN 1, which is the management VLAN that all switch ports are assigned to unless otherwise defined. Additionally, certain reserved VLANs, such as 1002 through 1005, are created for special purposes such as the default token ring VLANs and FDDI VLANs.

Understanding this default configuration helps network administrators in their initial setup and management of switch VLANs. VLAN 1 can often be a target for security concerns, which is why it's generally recommended to configure a different management VLAN for enhanced security.

The additional VLANs that exist by default—1002 through 1005—serve specific networking roles. Awareness of these VLANs is essential for maintaining effective network designs and configurations.