Spanning Tree Protocol (STP) and Rapid Spanning Tree Protocol (RSTP) are both used in Cisco Networking to prevent loops in switch networks that may cause broadcast storms and network outages. While STP is a legacy protocol that was introduced before RSTP, RSTP is an improved version of STP. In this article, we will discuss the differences between STP and RSTP and determine which protocol is better for Cisco Networking.
Spanning Tree Protocol (STP)
The Spanning Tree Protocol is a legacy protocol that works by preventing loops in switch networks by allowing one path between network nodes. It does this by disabling links that create loops in the network topology, thus allowing a single path between network nodes. STP operates by using Bridge Protocol Data Units (BPDUs) to determine the root bridge, which is the central node that all other nodes communicate with. STP also uses blocking, forwarding, and listening states to prevent network loops.
The major drawbacks of STP are that it is a slow protocol, with a convergence time of around 30 seconds, and it is prone to network loops if not configured correctly. Another issue with STP is that it can cause network outages when a link fails, as it needs to recalculate the network topology.
Rapid Spanning Tree Protocol (RSTP)
Rapid Spanning Tree Protocol (RSTP) is an improvement on STP designed to address its speed and convergence issues. RSTP eliminates the listening state and introduces a new state called the “learning” state, which allows switches to immediately start forwarding data packets. RSTP achieves faster convergence times by using Protocol Independent Multicast (PIM) messages to communicate topology changes, as opposed to relying entirely on BPDUs.
RSTP also offers faster link failover times by introducing a new “edge” port type that immediately transitions to forwarding mode when a link is activated. One of the significant advantages of RSTP is that it is backward compatible with STP, meaning it can be used in a network with mixed devices.
Which is Better: STP or RSTP?
Given that RSTP is an improved version of STP, it is generally considered better in Cisco Networking. RSTP is faster, more efficient, and less prone to network outages and loops than STP. It has a faster convergence time and faster link failover times, making it a more stable protocol for networks. Furthermore, RSTP is backward compatible with STP, making it an easy upgrade path for networks that are currently using STP.
Conclusion
Both STP and RSTP are used for preventing loops in switch networks and ensuring faster and more reliable network performance. However, RSTP has improved technology that provides faster convergence times and a higher level of network failover and stability than STP. Therefore, it is recommended to use RSTP on Cisco Networking.