Link aggregation, in other words trunking, is a technique that helps to increase bandwidth by bundling multiple physical interfaces into a logical one, named Eth-trunk. Besides bandwidth increase, trunking lets us to implement load-balancing and ensure higher reliability.
Few restrictions must be taken into consideration when creating Eth-trunk interface:
- parameters of physical interfaces (number, transmission rate, duplex mode and traffic-control mode) on both ends of the trunk link must be consistent.
- data sequence must be unchanged (frames belonging to the same data flow are transmitted over the same physical link).
Eth-Trunk interfaces configured on S5700 switch support the following features:
- Layer 2 forwarding and Layer 3 forwarding (unicast and multicast).
- Hash algorithm-based load balancing.
- QoS on the trunk interface.
There are 2 methods of link aggregation:
- manual load balancing mode