D-Link DES-3028 User Manual - Trunking

DES-3028 DES-3028P DES-3052 DES-3052P Layer 2 Fast Ethernet Managed Switch 

Trunking 

Port trunk groups are used to combine a number of ports together to make a single high-bandwidth data pipeline. 

The Switch supports up to six port trunk groups with 2 to 8 ports in each group. A potential bit rate of 800 Mbps can be achieved. 

Figure 7- 8. Example of Port Trunk Group 

The Switch treats all ports in a trunk group as a single port. Data transmitted to a specific host (destination address) will always be 

transmitted over the same port in a trunk group. This allows packets in a data stream to arrive in the same order they were sent.  

NOTE: If any ports within the trunk group become disconnected, packets 

intended for the disconnected port will be load shared among the other 

uplinked ports of the link aggregation group. 

Link aggregation allows several ports to be grouped together and to act as a single link. This gives a bandwidth that is a multiple 

of a single link's bandwidth. 

Link aggregation is most commonly used to link a bandwidth intensive network device or devices, such as a server, to the 

backbone of a network. 

The Switch allows the creation of up to six link aggregation groups, each group consisting of 2 to 8 links (ports). All of the ports 

in the group must be members of the same VLAN, and their STP status, static multicast, traffic control, traffic segmentation and 

802.1p default priority configurations must be identical. Port locking, port mirroring and 802.1X must not be enabled on the trunk 

group. Further, the aggregated links must all be of the same speed and should be configured as full-duplex. 

The Master Port of the group is to be configured by the user, and all configuration options, including the VLAN configuration that 

can be applied to the Master Port, are applied to the entire link aggregation group. 

Load balancing is automatically applied to the ports in the aggregated group, and a link failure within the group causes the 

network traffic to be directed to the remaining links in the group. 

The Spanning Tree Protocol will treat a link aggregation group as a single link, on the switch level. On the port level, the STP will 

use the port parameters of the Master Port in the calculation of port cost and in determining the state of the link aggregation group. 

If two redundant link aggregation groups are configured on the Switch, STP will block one entire group, in the same way STP will 

block a single port that has a redundant link. 

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