Dell PowerConnect 2708 User's Guide - Addendum - Page 3

Figure 9-2. Port-Based VLANs in the Enterprise Creating VLAN Membership VLANs are collections of switching ports that comprise a single broadcast domain. Packets are classified as belonging to a VLAN based on either the VLAN tag, or a combination of the ingress port and packet contents. Packets sharing common attributes can be grouped in the same VLAN. VLAN tagging provides a method of transferring VLAN information between VLAN groups. VLAN tagging attaches a 4-byte tag to packet headers. The VLAN tag indicates to which VLAN the packet belongs. VLAN tags are attached to the packets by either the end station or by the network device. VLAN tags also contains VLAN network priority information. VLAN membership is used to partition traffic into several mutually exclusive broadcast domains. VLAN membership facilitates greater security and pre-defined access levels of user groups in separate departments. The VLAN Membership Web Management page contains fields for defining VLAN groups. The device supports the mapping of 4094 VLAN IDs to 64 VLANs. All ports must have a defined PVID. If no other value is configured the default VLAN PVID is used. VLAN ID #1 is the default VLAN, and cannot be deleted from the system. The VLAN Membership screen enables the user to select an existing VLAN, create a new VLAN with port numbers, create a new VLAN port membership, or remove an existing VLAN. VLAN Membership ports can be defined as Untag Egress packets, Tag Egress packets, or they can be defined as Not Member. 3