Cisco Certified Network Professional Practice Test 2026 – Your All-in-One Guide to Exam Success!

During the first bridge protocol data unit (BPDU) exchange in Rapid Spanning Tree Protocol (RSTP), the behavior of edge ports is critical for maintaining network stability. Edge ports, which are ports connected directly to end stations, do not participate in the spanning tree protocol's topological changes in the same way as standard bridge ports.

When an edge port is initially in a state of receiving BPDUs, it will not enter the forwarding state immediately; instead, it will first discard frames. This means that if an edge port receives a BPDU, it understands that it is no longer purely an edge port since BPDUs typically indicate the presence of switches upstream. Consequently, the port must transition to a learning state to appropriately respond to the new network topology.

This initial action of discarding frames ensures that the switch does not forward inappropriate traffic that could disrupt the spanning tree process or introduce loops into the network. It is essential for the reliable operation of RSTP, which aims to quickly reconverge and maintain a loop-free topology, especially in dynamically changing environments.

While other options may describe actions associated with different states or roles in the spanning tree process, the specific initial action for edge ports during this first BPDU exchange is to