H3C Technologies H3C S3600 Series Switches - Manual (Page 104)

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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 H3C S3600 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 S3600 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.
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 S3600 series switches support the port-based and protocol-based VLANs.
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.
Ports on Ethernet switches have the three link types: access, trunk, and hybrid. For the three types of
ports, the process of being added into a VLAN and the way of forwarding packets are different.
Port-based VLANs are easy to implement and manage and applicable to hosts with relatively fixed
positions.
Link Types of Ethernet Ports
The link type of an Ethernet port on the S3600 series can be one of the following:
z Access: An access port can belong to only one VLAN, and is generally connected to a user PC.
z Trunk: A trunk port can belong to more than one VLAN. It can forward packets for multiple VLANs,
and is generally connected to another switch.