Author: upravnik

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 …

NOTE This topic is not included in the latest version of the CCNA exam (200-301). If you are studying for the exam feel free to skip this article.   We’ve already learned that using VTP makes it is possible to Read More …

NOTE This topic is not included in the latest version of the CCNA exam (200-301). If you are studying for the exam feel free to skip this article.   Each switch can use one of four different VTP modes: VTP Read More …

NOTE This topic is not included in the latest version of the CCNA exam (200-301). If you are studying for the exam feel free to skip this article.   VTP (VLAN Trunking Protocol) is a Cisco proprietary protocol used by Read More …

By default, all VLANs are allowed across a trunk link on a Cisco switch. We can verify that using the show interfaces trunk command: SW1#show interfaces trunk Port Mode Encapsulation Status Native vlan Fa0/1 on 802.1q trunking 1 Port Vlans Read More …