D-Link xStack DGS-3426P User Manual - Link Aggregation

xStack DGS-3400 Series Layer 2 Gigabit Ethernet Managed Switch 

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

the disconnected port will be load shared among the other linked ports of the link 

aggregation group. 

NOTE: Trunking may be done across switches in the switch stack without any 

limitations. 

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 32 link aggregation groups, each group consisting of 2 to 8 links (ports). The (optional) 

Gigabit ports can only belong to a single link aggregation group. 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 LACP 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. 

Link Aggregation 

To configure port trunking, click on the Link Aggregation hyperlink in the Trunking folder under L2 Features to bring up the 

following window: 

Figure 7- 15. Link Aggregation Group Entries table 

To configure port trunk groups, click the Add button to add a new trunk group and use the Link Aggregation Group 

Configuration window (see example below) to set up trunk groups. To modify a port trunk group, click the Hyperlinked Group 

ID. To delete a port trunk group, click the corresponding   under the Delete heading in the Link Aggregation Group Entries 

table. 

124