Category: STP and RSTP

Most newer Cisco switches use RSTP by default. RSTP prevents frame looping out of the box and no additional configuration is necessary. To check whether a switch runs RSTP, the show spanning-tree command is used: SW1#show spanning-tree VLAN0001 Spanning tree Read More …

Just like STP, RSTP creates a topology database of the network. To prevent loops, some interfaces on switches are placed in forwarding state and other interfaces in discarding state. How does RSTP decides in which state the port will be Read More …

RSTP (Rapid Spanning Tree Protocol) is an evolution of STP. It was originally introduced as IEEE 802.1w standard and in 2004 IEEE decided to replace STP with RSTP in 802.1D standard. Finally, in 2011, in the IEEE decided to move Read More …

We’ve already learned that, on the shared Ethernet segments, the switch with the best path to reach the root switch is placed in forwarding state. That switch is called the designated switch and its port is known as the designated Read More …

As we’ve mentioned before, all working interfaces on the root switch are placed in forwarding state. All other switches (called nonroot switches) determine the best path to get to the root switch and the port used to reach the root Read More …

The STP process works by default on Cisco switches and begins with the root switch election. The election is based on the bridge IDs (BIDs) sent in the BPDUs. Each switch that participates in STP will have a 8-byte switch Read More …

STP uses the Spanning-Tree Algorithm (SPA) to create a topology database of the network. To prevent loops, SPA places some interfaces in forwarding state and other interfaces in blocking state. How does STP decides in which state the port will Read More …

Spanning Tree Protocol (STP) is a network protocol designed to prevent layer 2 loops. It is standardized as IEEE 802.D protocol. STP blocks some ports on switches with redundant links to prevent broadcast storms and ensure loop-free topology. With STP Read More …