In STP, the bridge ID on the switching network is as follows. With which of the following bridge IDs is the switch selected as the root bridge?

The root bridge election is determined by the lowest Bridge ID (BID). The BID is a combination of bridge priority and MAC address. The comparison first looks at the priority value; the lowest priority wins. In this case, the bridge with priority 4096 is the lowest among the options (4096 vs. 32768). Therefore, the switch with the BID "4096 00-01-02-03-04-DD" will be elected as the root bridge, and the MAC address comparison is not necessary.

A. This switch has a priority of 32768, which is higher (less preferred) than 4096.
C. This switch has a priority of 32768, which is higher (less preferred) than 4096.
D. This switch has a priority of 32768, which is higher (less preferred) than 4096.

1. Huawei HedEx Documentation, S12700 Series Switches V200R019C10 Configuration Guide - Ethernet Switching, Section: "Spanning Tree Protocol Configuration > STP/RSTP/MSTP Overview > Root Bridge Election". This section explains that the switch with the smallest bridge ID becomes the root, and the priority is the most significant part of the ID.