H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 77)

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received packets and the corresponding ports receiving the packets for consequent packet forwarding.
The process of recording is called MAC address learning.
After VLANs are configured on a switch, the MAC address learning of the switch has the following two
modes.
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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.
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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 MAC Address Forwarding Table Management in H3C WX3000 Series Unified
Switches Switching Engine Configuration Guide .
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.
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Port-based VLANs
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MAC address-based VLANs
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Protocol-based VLANs
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IP-subnet-based VLANs
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Policy-based VLANs
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Other types