3Com 3CBLSF26H manual Aggregating Port, Overview, Link Aggregation Types

Table 3-20VLAN Port Detail Page item description

Item	Description
Untagged	Indicates the port is an untagged member of the VLAN.
Membership
Tagged membership	Indicates the port is a tagged member of a VLAN. VLAN tagged frames are
	forwarded by the interface. The frames contain VLAN information.

Aggregating Port

Overview

Link aggregation aggregates multiple physical Ethernet ports into one logical link, called a Link Aggregation Group (LAG).

It allows you to increase bandwidth by distributing traffic across the member ports in the aggregation group. In addition, it provides reliable connectivity because these member ports can dynamically back up each other.

LACP

Link Aggregation Control Protocol (LACP) based on the IEEE802.3ad standard can be used for dynamic link aggregation. An LACP-enabled port sends link aggregation control protocol data units (LACPDUs) to tell the peer about its system priority, system MAC address, port priority, port number and operation key. After receiving the information from the sender, the receiver compares it with the locally saved information about other ports, chooses member ports for the aggregation group and reaches agreement about whether a port can join or leave a dynamic aggregation group.

During link aggregation, LACP generates a configuration mix according to the port configuration (rate, duplex, basic configuration, management key), which is called an operation key.

Link Aggregation Types

The switch supports two link aggregation types:

zManual Aggregation

zStatic LACP Aggregation

1)Manual Aggregation

Manual aggregation is configured manually, and cannot be added or removed automatically. A manual or static LACP aggregation group must contain at least a member port. Member ports in a manual aggregation are LACP-disabled.

A port in a manual aggregation group can be in one of the two states: selected or unselected. In a manual aggregation group, only the selected ports can forward user service packets.

In a manual aggregation group, the system sets the ports to selected or unselected state according to the following rules.

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