H3C Technologies H3C WX3000 Series Unified Switches - Manual (Page 117)

15-2
Link Types of Ethernet Ports
An Ethernet port of the device can operate in one of the following three link types:
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Access: An access port can belong to only one VLAN, and is generally used to connect user PCs.
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Trunk: A trunk port can belong to more than one VLAN. It can receive/send packets from/to multiple
VLANs, and is generally used to connect another device.
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Hybrid: A hybrid port can belong to more than one VLAN. It can receive/send packets from/to
multiple VLANs, and can be used to connect either a device or user PC.
A hybrid port allows the packets of multiple VLANs to be sent without tags, but a trunk port only allows
the packets of the default VLAN to be sent without tags.
You can configure all the three types of ports on the same Ethernet switch. However, note that you
cannot directly switch a port between trunk and hybrid and you must set the port as access before the
switching. For example, to change a trunk port to hybrid, you must first set it as access and then hybrid.
Configuring the Default VLAN ID for an Ethernet Port
An access port can belong to only one VLAN. Therefore, the VLAN an access port belongs to is also the
default VLAN of the access port. A hybrid/trunk port can belong to several VLANs, and so a default
VLAN ID for the port is required.
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After you configure default VLAN IDs for Ethernet ports, the packets passing through the ports are
processed in different ways depending on different situations:
Table 15-3 Processing of incoming/outgoing packets
Processing of an incoming packet
Port
type
If the packet
does not carry a
VLAN tag
If the packet carries a VLAN
tag
Processing of an outgoing packet
Access
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If the VLAN ID is just the
default VLAN ID, receive
the packet.
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If the VLAN ID is not the
default VLAN ID, discard
the packet.
Deprive the tag from the packet and send the
packet.
Trunk
Receive the
packet and add
the default tag to
the packet.
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If the VLAN ID is just the
default VLAN ID, receive
the packet.
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If the VLAN ID is not the
default VLAN ID but is one
f h VLAN ID ll d
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If the VLAN ID is just the default VLAN ID,
deprive the tag and send the packet.
z If the VLAN ID is not the default VLAN ID,
keep the original tag unchanged and send
the packet.