What is the default VLAN for Cisco switch interfaces?

The default VLAN for Cisco switch interfaces is VLAN 1. All switch ports on a Cisco switch will belong to VLAN 1 by default unless they are explicitly configured to be a part of other VLANs. VLAN 1 serves important functions, such as carrying management traffic, and is often used for protocols like CDP (Cisco Discovery Protocol), VTP (VLAN Trunking Protocol), and STP (Spanning Tree Protocol).

Choosing VLAN 1 as the default VLAN can be crucial for uniformity and compatibility across different devices on the network. While switches can be configured to have different VLANs based on network requirements, VLAN 1 remains as the starting point for all switch ports unless reconfigured. This default is integral for understanding how to manage and segment traffic within a network, especially for newer network administrators who may start with the out-of-the-box configurations of Cisco switches.