D-Link DXS-3600 Series Reference Manual page 143

DXS-3600 Series Layer 3 Managed 10Gigabit Ethernet Switch Web UI Reference Guide
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.
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 up to 12 links
(ports). Each port 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 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.
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.
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.
Figure 5-50 Example of Port Trunk Group
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