13.Port Trunk Configuration
Ports can be combined into an aggregate link to increase the bandwidth of a net-
work connection where bottlenecks exist or to ensure fault recovery. You can
create up to six trunks at a time, with any single trunk containing up to four ports.
The switch supports both static trunking and dynamic LACP (Link Aggregation
Control Protocol). LACP configured ports can automatically negotiate a trunked
link with LACP-configured ports on another device. You can enable LACP on any
port that is not already a member of a static trunk. If LACP is also enabled for the
connected ports on another device, the switch and the other device will automati-
cally create a trunked link.
Besides balancing the load across each port in the trunk, the other ports provide
redundancy by taking over the load if a port in the trunk fails. However, before
making any physical connections between devices, use the Web interface or CLI
to specify the trunk on the devices at both ends. When using a port trunk, take
note of the following points:
> Finish configuring port trunks before you connect the corresponding network
cables between switches to avoid creating a loop.
> The ports at both ends of a connection must be configured as trunk ports.
> The ports at both ends of a trunk must be configured in an identical manner,
including communication mode (i.e., speed, duplex mode and flow control),
VLAN assignments, and CoS settings.
> All ports on both ends of an LACP trunk must be configured for full duplex,
either by forced mode or auto-negotiation.
> All the ports in a trunk have to be treated as a whole when moved from/to,
added or deleted from a VLAN.
> STP, VLAN, and IGMP settings can only be made for the entire trunk.
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