链路聚合（英语：Link Aggregation）是一个计算机网络术语，又称Trunk，是指将多个物理端口捆绑在一起，成为一个逻辑端口，以实现出/ 入流量吞吐量在各成员端口中的负荷分担，交换机根据用户配置的端口负荷分担策略决定报文从哪一个成员端口发送到对端的交换机。当交换机检测到其中一个成员端口的链路发生故障时，就停止在此端口上发送报文，并根据负荷分担策略在剩下链路中重新计算报文发送的端口，故障端口恢复后再次重新计算报文发送端口。链路聚合在增加链路带宽、实现链路传输弹性和工程冗余等方面是一项很重要的技术。

In computer networking, the term link aggregation applies to various methods of combining (aggregating) multiple network connections in parallel in order to increase throughput beyond what a single connection could sustain, and to provide redundancy in case one of the links should fail. A LAG (Link Aggregation Group) combines a number of physical ports together to make a single high-bandwidth data path, so as to implement the traffic load sharing among the member ports in the group and to enhance the connection reliability.