Load Sharing in a Link Aggregation Group 165You need to maintain the basic configurations of these ports manually to ensureconsistency. As one configuration change may involve multiple ports, this canbecome troublesome if you need to do that port by port. As a solution, you mayadd the ports into an aggregation port group where you can make configurationfor all member ports.When the configuration of some port in a static aggregation group changes, thesystem does not remove the aggregation; instead, it re-sets theselected/unselected state of the member ports and re-selects a master port.Load Sharing in a LinkAggregation GroupLink aggregation groups fall into load sharing aggregation groups and non-loadsharing aggregation groups depending on their support to load sharing.A load sharing aggregation group can contain at least one selected port but anon-load sharing aggregation group can contain only one.Link aggregation groups perform load sharing depending on availability ofhardware resources. When hardware resources are available, link aggregationgroups created containing at least two selected ports perform load sharing, whilelink aggregation groups created with only one selected port does not perform loadsharing. After hardware resources become depleted, link aggregation groupscreated work in non-load sharing mode.Load sharing is implemented through the selected ports in an aggregation group.However, the way of selecting forwarding ports varies by packet type:■ For a Layer-2 unicast packet with a known destination MAC address, if thepacket carries an IP datagram, the switch selects the forwarding port accordingto the source IP address and destination IP address; otherwise, the switchselects the forwarding port according to the source MAC address anddestination MAC address.■ For a unicast IP packet with a known destination IP address, the switch selectsthe forwarding port according to the source IP address and the destination IPaddress of the packet.■ For a Layer-2 multicast packet with a known destination MAC address, theswitch selects the forwarding port according to the source MAC address, thedestination MAC address, and the receiving port of the packet.■ For a Layer-3 multicast packet with a known IP address, the switch selects theforwarding port according to the source IP address, the destination IP address,and the receiving port of the packet.■ For an unknown unicast/multicast/broadcast packet, the switch selects theforwarding port according to the source MAC address, the destination MACaddress, and the receiving port of the packet.n When only one selected port remains in a load sharing aggregation group, thegroup keeps working in the load sharing mode.Service Loop Group You can create a service loop group by creating a manual aggregation group ofservice-loop ports first and then specifying which services can be redirected for the
