3Com 3C16491 manual Link Aggregation, Guidelines for Creating Trunks

56CHAPTER 4: CONFIGURING THE SWITCH

1000 Mbps connections are always full-duplex. Half-duplex connections are only available for 10 Mbps and 100 Mbps settings.

CAUTION: Before manually setting a port to full-duplex, verify that the device connected to the port is also manually set to the same speed and duplex setting. If connecting link partners are left to autonegotiate for a link manually set on this switch to full-duplex, they will always negotiate to half-duplex, resulting in a duplex mismatch. This can result in a significant reduction in network performance. If you are unsure of how to configure the speed/duplex setting, simply enable autonegotiation for the port.

You cannot modify the speed/duplex settings of ports that are members of a trunk or aggregated link.

Supported SFP transceivers only operate at 1000 Mbps full-duplex. Inserting an SFP transceiver into a gigabit port disables the corresponding RJ-45 port, even if no fiber cable is inserted.

Link Aggregation

Link aggregation, also called “trunking”, refers to bonding multiple ports into a single group to effectively combine the bandwidth into a single connection or a “trunk”. If you are connecting the Switch to another switch or to an Internet backbone, you can aggregate links on the Switch to increase throughput and prevent packet loopback between switches.

For link aggregation to work, the trunks must be configured on both ends (switches).

Guidelines for Creating Trunks

■Any port on the Switch can be used for creating a trunk.

■This switch supports a maximum of four trunks.

■Each trunk may contain up to four members.

■A port may only be a member of one trunk at any one time.