You must have the doubt what’s the function of the several ports in a switch. Then you need to know what the link types and port types are.

WHAT ARE THE LINK TYPES

The link type of VLAN can be divided into access link and trunk link.

Access link is part of only one VLAN, and normally is for end devices. Any device attached to an access link is unaware of a VLAN membership. An access-link connection can understand only standard Ethernet frames. Switches remove any VLAN information from the frame before it is sent to an access-link device.

Trunk link can carry multiple VLAN traffic and normally is used to connect switches to other switches or to routers.

WHAT ARE THE PORT TYPES?

Access ports:

• Belong to one VLAN.

• Commonly used to connect computer ports.

Trunk ports:

• Allow multiple VLANs through.

• Receive and send multiple VLAN packets.

• Typically used for connection between switches.

Hybrid ports:

• Allow multiple VLANs through.

• Receive and send multiple VLAN packets.

• Used for connection between switches, or switch and computer.

You may get well understood on those ports in following table.

Here is an egg how these ports perform in a system.

Access port

Strip the VLAN information in the packet and forward the packet directly.

Trunk port

1. Compare the PVID of the port and the VLAN information in the packet to be transmitted.

2. If they are the same, proceed to Step 3, otherwise, proceed to Step 4

3. Strip the VLAN information in the packet and forward  the packet.

4. Forward the packet directly.

Hybrid port

1. Check the VLAN attributes on this port by running the command disp interface to se whether the VLAN attributes is "tagged" or "untagged"

2. If I is untagged, proceed to Step 3, if it is tagged, proceed to step 4.

3. Strip the VLAN information in the packet and forward the packet.

4. Forward the packet directly.