200-301: Cisco Certified Network AssociateDemo

IEEE 802.1Q is the standards-based VLAN trunking method used to carry multiple VLANs between switches from different vendors. It inserts a VLAN tag into Ethernet frames so both switches can identify the VLAN membership across the trunk. ISL is Cisco-proprietary, while DSCP and IEEE 802.1p are QoS mechanisms rather than interswitch VLAN trunking protocols.