The normal range allows for VLANs 1 -1005; IEEE 802.1Q expands this to 1 – 4095.
VTP version 1 and 2 only support VLANs 1 – 1005. VTPv3 will support extended VLANs but isn’t available yet.
Dynamic VLANs can be configured by a VLAN Membership Policy Server (VMPS).
Inter-Switch Link (ISL) – Cisco proprietary; 26-byte header
IEEE 802.1Q – Open standard; 4-byte header
IEEE 802.3ac extends the Ethernet MTU to 1522 to account for the 4-byte 802.1Q header.