IEEE 802.1aq (英语：Shortest Path Bridging， 简称 SPB 是一个 计算机网络 术语. 802.1aq 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。 802.1aq 是一个合乎逻辑的升级 生成树协议 (Spanning Tree Protocol).  802.1aq 包括的功能 802.1s, 802.1w, 802.1ax (链路聚合), MC-LAG, 802.1ak.

Shortest Path Bridging (SPB), specified in the IEEE 802.1aq standard, is a computer networking technology intended to simplify the creation and configuration of networks, while enabling multipath routing.

It is the replacement for the older spanning tree protocols: IEEE 802.1D, IEEE 802.1w, IEEE 802.1s. These blocked any redundant paths that could result in a layer 2 loop, whereas SPB allows all paths to be active with multiple equal cost paths, provides much larger layer 2 topologies, supports faster convergence times, and improves the efficiency by allowing traffic to load share across all paths of a mesh network. It is designed to virtually eliminate human error during configuration and preserves the plug-and-play nature that established Ethernet as the de facto protocol at Layer 2.