Accton Technology ES4710BD - Manual (Page 285)

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E ES4710BD 10 Slots L2/L3/L4 Chassis Switch
Chapter 13 Port Channel Configuration
13.1 Introduction to Port Channel
To understand Port Channel, Port Group should be introduced first. Port Group is a group of
physical ports in the configuration level, only physical ports in the Port Group can take part in link
aggregation and become a member port of a Port Channel. Logically, Port Group is not a port but a
port sequence. Under certain conditions, physical ports in a Port Group perform port aggregation to
form a Port Channel that has all the properties of a logical port, therefore it becomes an independent
logical port. Port aggregation is a process of logical abstraction to abstract a set of ports (port
sequence) of the same properties to a logical port. Port Channel is a collection of physical ports and
used logically as one physical port. Port Channel can be used as a normal port by the user, and can
not only add network’s bandwidth, but also provide link backup. Port aggregation is usually used
when the switch is connected to routers, PCs or other switches.
Fig 14-1 Port aggregation
As shown in the above figure, ports 1-4 of switch S1 is aggregated to a Port Channel, the bandwidth
of this Port Channel is the total of all the four ports. If traffic from S1 needs to be transferred to S2
through the Port Channel, traffic allocation calculation will be performed based on the source MAC
address and the lowest bit of target MAC address.The calculation result will decide which port to
convey the traffic. If a port in Port Channel fails, the other ports will undertake traffic of that port
through a traffic allocation algorithm. This algorithm is carried out by the hardware.
ES4710BD offers 2 methods for configuring port aggregation: manual Port Channel creation and
LACP (Link Aggregation Control Protocol) dynamic Port Channel creation. Port aggregation can
only be performed on ports in full-duplex mode.
For Port Channel to work properly, member ports of the Port Channel must have the same properties
as follows: