Link Aggregation Menu Screen (802.3ad Main Menu Screen)
Port Configuration Menu Screens 5-25
Link Aggregation
It is desirable to have a way to use multiple interswitch links simultaneously to increase
interswitch bandwidth. This can be done if both sides agree on a set of ports that are being used as
an interswitch link called a “Trunk.” As long as both switches agree on which ports are in this
trunk, there are no problems with looping, and the Spanning Tree can treat this trunk as a single
port.
Proprietary Aggregation Methods
Most switch vendors provide a way to group these ports together manually. For example, the user
could configure Ports 1, 2 and 3 in a trunk on switch X and connect to ports 4, 5 and 6 that are in a
trunk on switch Y. By interconnecting the switches together, the effective bandwidth can be
aggregated to the sum of the parts. The Enterasys Networks’ implementation is called
SmartTrunking.
IEEE 802.3ad
All the methods of trunking multiple links have involved manually choosing the links that are part
of the trunk. The IEEE 802.3ad specification allows the switch to determine which links are in
trunks and configure them dynamically. Since the protocol is based on IEEE standards
specifications, any switch from any vendor that supports this protocol can trunk links
automatically.
How to Access
Use the arrow keys to highlight the LINK AGGREGATION MENU item in the Port
Configuration Menu screen described in Section 5.1 and press ENTER. The 802.3ad MAIN
MENU screen, Figure 5-8, displays.