3Com 2500 manual XNS data received matches no protocol, Ports, Is flooded on

2-6 CHAPTER 2: VLANS ON THE LANPLEX® SYSTEM

This example shows how flooding decisions are made according to VLANs set up by protocol (assuming an 18-port switch):

Index 1 2 3

Data received on...	Is flooded on...
IP - port 1	VLAN 2

VLAN Ports

Default 1 - 18

IP1 - 12

IPX11 - 16

Because...

IP data received matches IP VLAN on the source port.

IPX - port 11	VLAN 3	IPX data received matches IPX VLAN on the
		source port.
XNS - port 1	VLAN 1	XNS data received matches no protocol
		VLAN, so the Default VLAN is used.

VLAN Exception If data arrives on a switch port for a certain protocol and VLANs for that Flooding protocol are defined in the system but not on that switch port, the default

VLAN defines the flooding domain for that data. This case is called VLAN exception flooding.

This example shows how the VLAN exception flooding decision is made (assuming an 18-port switch):

Index	VLAN	Ports
1	Default	1 - 18
2	IP	1 - 10