H3C Technologies H3C S3100 Series Switches - Manual (Page 86)

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z Shared VLAN learning (SVL), where the switch records all learned MAC address entries in one
MAC address table, regardless of in which VLAN they are learned. This table is called the shared
MAC address forwarding table. Packets received in any VLAN on a port are forwarded according to
this table.
z Independent VLAN learning (IVL), where the switch maintains an independent MAC address
forwarding table for each VLAN. The source MAC address of a packet received in a VLAN on a port
is recorded to the MAC address forwarding table of this VLAN only, and packets received in a
VLAN are forwarded according to the MAC address forwarding table for the VLAN.
Currently, the H3C S3100 series Ethernet switches adopt 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 S3100 series Ethernet switches support 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.
An S3100 series switch can be configured with a single VLAN interface only, and the VLAN must be the
management VLAN. For details about the management VLAN, refer to the “Management VLAN
Configuration” part of this manual.
VLAN Classification
Depending on how VLANs are established, VLANs fall into the following six categories.
z Port-based VLANs
z MAC address-based VLANs
z Protocol-based VLANs
z IP-subnet-based VLANs
z Policy-based VLANs
z Other types
At present, the S3100 series switches support the port-based and protocol-based VLANs.