3Com WX3000 operation manual Port-Based Vlan, Vlan Interface, Vlan Classification

Models: WX3000

1 715
Download 715 pages 21.26 Kb
Page 65
Image 65

After VLANs are configured on a switch, the MAC address learning of the switch has the following two modes.

z

z

Shared VLAN learning (SVL): the switch records all the MAC address entries learnt by ports in all VLANs to a shared MAC address forwarding table. Packets received on any port of any VLAN are forwarded according to this table.

Independent VLAN learning (IVL): the switch maintains an independent MAC address forwarding table for each VLAN. The source MAC address of a packet received on a port of a VLAN is recorded to the MAC address forwarding table of this VLAN only, and packets received on a port of a VLAN are forwarded according to the VLAN’s own MAC address forwarding table.

Currently, the device adopts the IVL mode only. For more information about the MAC address forwarding table, refer to the “MAC Address Forwarding Table Management” part of the manual.

VLAN Interface

Hosts in different VLANs cannot communicate with each other directly unless routers or Layer 3 switches are used to do Layer 3 forwarding. The device supports VLAN interfaces configuration to forward packets in Layer 3.

VLAN interface is a virtual interface in Layer 3 mode, used to realize the layer 3 communication between different VLANs, and does not exist on a switch as a physical entity. Each VLAN has a VLAN interface, which can forward packets of the local VLAN to the destination IP addresses at the network layer. Normally, since VLANs can isolate broadcast domains, each VLAN corresponds to an IP network segment. And a VLAN interface serves as the gateway of the segment to forward packets in Layer 3 based on IP addresses.

The switching engine used in the device can be configured with a maximum number of eight VLAN interfaces.

VLAN Classification

Depending on how VLANs are established, VLANs fall into the following six categories.

z

z

z

z

z

z

Port-based VLANs

MAC address-based VLANs Protocol-based VLANs IP-subnet-based VLANs Policy-based VLANs Other types

Port-Based VLAN

Port-based VLAN technology introduces the simplest way to classify VLANs. You can assign the ports on the device to different VLANs. Thus packets received on a port will be transmitted through the corresponding VLAN only, so as to isolate hosts to different broadcast domains and divide them into different virtual workgroups.

1-4

Page 65
Image 65
3Com WX3000 operation manual Port-Based Vlan, Vlan Interface, Vlan Classification