Dell PowerConnect 54 Series, User Manual

Page: 323 / 416

Configuring Device Information
323
Aggregating Ports
Port Aggregation optimizes port usage by linking a group of ports together to form a single Link Aggregated
Group (LAG). Port Aggregation multiplies the bandwidth between the devices, increases port flexibility, and
provides link redundancy. The device supports up to eight LAGs per system, and eight ports per LAG per
device.
Each LAG is composed of ports of the same speed, set to full-duplex operations. Ports in a LAG, can be of
different media types (UTP/Fiber, or different fiber types), provided they operate at the same speed.
Aggregated Links can be assigned manually or automatically by enabling
Link Aggregation Control
Protocol (LACP) on the relevant links. The device provides LAG Load Balancing based on both source
MAC addresses and destination MAC addresses.
Aggregated Links are treated by the system as a single logical port. Specifically, the Aggregated Link has
similar port attributes to a non-aggregated port, including auto-negotiation, speed, Duplex setting, etc.
The device supports both static LAGs and
Link Aggregation Control Protocol (LACP) LAGs. LACP LAG
negotiate Aggregated Port links with other LACP ports located on a different device. If the other device
ports are also LACP ports, the devices establish a LAG between them.
The following guidelines should be followed when adding ports to a LAG:
• There is no Layer 3 interface defined on the port.
• The port does not belong to any VLAN.
• The port does not belong to any other LAG.
• The port is not a mirrored port.
• The port's 802.1p priority is equal to LAGs 802.1p priority.
• QoS Trust is not disabled on the port.
• GVRP is not enabled.
Ports can be configured as LACP ports only if the ports are not part of a previously configured LAG.
The device uses a hash function to determine which frames are carried on which aggregated-link member.
The hash function statistically load-balances the aggregated link members. The device considers an
Aggregated Link as a single logical port.
Each Aggregated Link has an Aggregated Link Port Type, including Gigabit Ethernet ports. Ports can be
added to an Aggregated Link only if they are the same port type. When ports are removed from an
Aggregated Links, the ports revert to the original port settings. To open the
Link Aggregation page, click
Switch
→
Link Aggregation in the tree view.