3Com 2500 manual VLAN Configuration Protocol Suite, About VLANs

About VLANs 2-3

layer 3 subnet address information. Protocol-sensitive VLANs allow the restriction of flood traffic for both routable and nonroutable protocols. They have a relatively simple configuration comprising one or more protocols and groups of switch ports. These protocol-sensitive VLANs operate independent of each other. Additionally, the same switch port can belong to multiple VLANs. For example, you can assign port 1 on a LANplex to several IP subnet VLANs, plus one IPX VLAN, one AppleTalk VLAN, and one NetBIOS VLAN. In a multiprotocol environment, protocol-sensitive VLANs can be very effective for controlling broadcast and multicast flooding.

Two or more types of VLANs can coexist in the LANplex system. When associating received data with a particular VLAN configuration in a multiple VLAN configuration, port group, MAC address group, and application-oriented VLANs always take precedence over protocol-sensitive VLANs.

LANplex The LANplex protocol-sensitive VLAN configuration includes three elements: Protocol-Sensitive protocol suite, switch ports, layer 3 addressing information for IP VLANs.

VLAN Configuration

Protocol Suite

The protocol suite describes which protocol entities can comprise a protocol-sensitive VLAN. For example, LANplex VLANs support the IP protocol suite, which is made up of the IP, ARP, and RARP protocols.

Table 2-1 lists the protocol suites that the LANplex supports, as well as the protocol types included in each protocol suite.

Table 2-1 Supported Protocols for VLAN Configuration

Protocol Suite	Protocol Types
IP	IP, ARP, RARP (Ethertype, SNAP PID)
Novell® IPX	IPX (Ethertype, DSAP, SNAP PID)
AppleTalk®	DDP, AARP (Ethertype, SNAP PID)
Xerox® XNS	XNS IDP, XNS Address Translation, XNS Compatibility
	(Ethertype, SNAP PID)
DECnet™	DEC MOP, DEC Phase IV, DEC LAT, DEC LAVC (Ethertype,
	SNAP PID)
SNA	SNA Services over Ethernet (Ethertype)
Banyan VINES®	Banyan (Ethertype, DSAP, SNAP PID)
continued