■The Main Server is a
■The Accounting Server is available to VLAN 3 only. It is isolated from all traffic on VLANs 1 and 2. The switch port connected to the server has tagging turned off.
■Clients 1 and 2 are attached to a shared media hub that is then connected to the switch. They belong to VLAN 2 only, and are logically in the same IP subnet as the Main Server and Client 5. The switch port connected to this segment has tagging turned off.
■Client 3 is a member of VLAN 1, and can communicate only with the Main Server and Client 5. Tagging is not enabled on Client 3’s switch port.
■Client 4 is a member of VLAN 3, and can communicate only with the servers. Tagging is not enabled on Client 4’s switch port.
■Client 5 is a member of both VLANs 1 and 2, and has a Sun GigabitEthernet adapter installed. It is connected to switch port 10. Both the adapter and the switch port are configured for VLANs 1 and 2 and have tagging enabled.
VLAN tagging is only required to be enabled on switch ports that create trunk links to other
Configuring VLANs
VLANs can be created according to various criteria, but each VLAN must be assigned a VLAN tag or VLAN ID (VID). The VID is a
Tagging an Ethernet frame requires the addition of a tag header to the frame. The header is inserted immediately following the Destination MAC address and the Source MAC address. The tag header consists of two bytes of Ethernet Tag Protocol Identifier (TPID, 0x8100) and two bytes of Tag Control Information (TCI).
shows the Ethernet Tag Header format.
Chapter 5 Configuring VLANs 47