In the last article, we learned what bridging means. This article talks about the role of bridging routers.
In the CISCO router with transparent bridging, the use of Spanning Tree Protocol can avoid the broadcasting storm caused by bridging. Spanning tree protocol defines the communication form of each bridge in the network through "Bridge Protocol Data Units". Its logical structure is like a tree. Each bridge is a branch of the tree and has its own path value, Bridge Id and priority. The bridge with the lowest priority is the root. If the priority is the same, the bridge with the lowest bridge ID is chosen. Packets are transmitted through the path formed by the root bridge and other bridges, and the top bridge will block the interface and only receive BPDU packets, which effectively solves the problem of broadcast diffusion.