D-Link DES-3326 manual To configure a link aggregation group, 241

DES-3326 Layer 3 Fast Ethernet Switch User’s Guide

An STP Group spanning tree works in the same way as the switch-level spanning tree, but the root bridge concept is replaced with a root port concept. A root port is a port of the group that is elected on the basis of port priority and port cost, to be the connection to the network for the group. Redundant links will be blocked, just as redundant links are blocked on the switch level.

The STP on the switch level blocks redundant links between switches (and similar network devices). The port level STP will block redundant links within an STP Group.

It is advisable to define an STP Group to correspond to a VLAN group of ports.

The following fields can be set:

Parameter	Description
Cost	A Port Cost can be set from 1 to
	65535. The lower the number, the
	greater the probability the port will
	be chosen to forward packets.
Priority	A Port Priority can be from 0 to 255.
	The lower the number, the greater
	the probability the port will be
	chosen as the Root Port.

Link Aggregation

To configure a link aggregation group:

Click the Link Aggregation link on the Configuration menu:

Figure 7-61. Link Aggregation window

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 DES-3326 allows the creation of up to 6 link aggregation groups, each group consisting of up of up to 8 links (ports). The aggregated links must be contiguous (they must have sequential port numbers) except the two (optional) Gigabit ports – which can only belong to a single link aggregation group. A link

241