3Com 9100 manual Accessing the Switch

58CHAPTER 3: ACCESSING THE SWITCH

Load Sharing on Load sharing with Switch 9100 devices allows you to increase bandwidth

the Switch 9100 and resilience between switches by using a group of ports to carry traffic in parallel between switches. The sharing algorithm allows the switch to use multiple ports as a single logical port. For example, VLANs see the load-sharing group as a single logical port. The algorithm also typically guarantees packet sequencing between clients.

If a port in a load-sharing group fails, traffic is redistributed to the remaining ports in the load-sharing group. If the failed port becomes active again, traffic is redistributed to include that port.

Load sharing must be enabled on both ends of the link, or a network loop will result. The load sharing algorithms do not need to be the same on both ends of the link.

Load sharing is most useful in cases where the traffic transmitted from the switch to the load-sharing group is sourced from an equal or greater number of ports on the switch. For example, traffic transmitted to a two-port load-sharing group should originate from a minimum of two other ports on the same switch.

This feature is supported between Switch 9100 devices only, but may be compatible with third-party “trunking” or sharing algorithms. Check with your supplier for more information.

Load Sharing Load sharing algorithms allow you to select the distribution technique Algorithms used by the load-sharing group to determine the output port selection.

Algorithm selection is not intended for use in predictive traffic engineering. You can configure one of three load-sharing algorithms on the switch, as follows:

■Port-based — Uses the ingress port to determine which physical port in the load-sharing group is used to forward traffic out of the switch.

■Address-based — Uses addressing information to determine which physical port in the load-sharing group to use for forwarding traffic out of the switch. Addressing information is based on the packet protocol, as follows:

■IP packets — Uses the source and destination MAC and IP addresses, and the TCP port number.

■IPX packets — Uses the source and destination MAC address, and IPX network identifiers.