Dell PowerConnect 55xx Systems User Guide 485FILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Maintenance Projects\DellContax\sources\CxUGSwitching_VLAN.fmD E L L C O N F I D E N T I A L – P R E L I M I N A R Y 1 0 / 3 0 / 1 3 - F O R P R O O F O N LYProtocol GroupsProtocol groups are based on protocol-based VLANs.Protocol-based VLANsUntagged frames received on a VLAN-aware switch can be classified bymethods others than source port, such as data-link-layer protocolidentification. This classification method is referred to as protocol-basedVLANs.Protocol-based VLANs are useful for isolating Layer 2 traffic of various Layer3 protocols. If, for example, a switch serves IP stations and IPX stations thatcommunicate with a single VLAN-unaware server, without usingprotocol-based VLANs, all the Layer 2 Broadcast traffic would reach all thestations. With protocol-based VLANs, the switch can forward incomingtraffic from the server to stations in a specific VLAN only.Protocol-based VLANs are only available on General ports.Classification rules are set on a per-port basis, and may be sensitive to theframe's encapsulation. The default encapsulation assumed is Ethernet.On each port, a user can define associations between groups of data-link layerprotocols and ports. For each group/port combination, the user may set theVLAN to which frames incoming on that port will be classified if they belongto any of the protocols in the group.Several protocol-groups may be associated to a single port, and a protocolgroup may be assigned to multiple ports, if so desired.It is not guaranteed that the VLAN to which the frame is classified exists inthe system, or is active on that port.RestrictionsThe following frames (packet) types are supported: Ethernet, RFC 1042, andLLC Other.There may be dependencies between protocols and encapsulations, andspecifying one protocol may automatically add additional protocols to theprotocol-group, such as specifying IP implies ARP and vice-versa.
