- 01Getting Started
- 02Understanding the Operating Modes of Network Devices
- 03Entering Privileged EXEC Mode with enable
- 04Entering Configuration Mode with configure terminal
- 05Renaming the Switch with hostname
- 06Moving Between Modes with exit and end
- 07Entering Port Configuration with interface
- 08Enabling a Port with no shutdown
- 09Assigning an IP Address with ip address
- 10Labeling a Port with description
- 11Viewing the Configuration with show running-config
- 12Listing Interfaces with show ip interface brief
- 13What Is a VLAN? Splitting a Network Logically
- 14Creating a VLAN with vlan
- 15Naming a VLAN with name
- 16Setting the Port Type with switchport mode
- 17Assigning a Port to a VLAN with switchport access vlan
- 18Listing VLANs with show vlan brief
- 19Adding a Static Route with ip route
- 20Viewing the Routing Table with show ip route
- 21Testing Reachability with ping
- 22Tracing the Path with traceroute
- 23Checking OS Information with show version
- 24Checking the Time with show clock
- 25Saving the Configuration with copy running-config startup-config
- 26Saving with write memory (the Short Form)
- 27Setting a Login Message with banner motd
- 28Configuring the Console Line with line console 0
- 29Setting a Password with password
- 30Requiring the Password at Login with login
- 31Configuring Remote Access with line vty 0 4
- 32Creating an Access List with access-list
- 33Checking Access Lists with show access-lists
- 34Viewing the MAC Address Table with show mac address-table
- 35Discovering Neighbors with show cdp neighbors
- 36Viewing the ARP Table with show arp
- 37Understanding Loop Prevention with spanning-tree mode
- 38Rebooting the Device with reload
- 39Hands-On: Configure a Small Office Network
Understanding Loop Prevention with spanning-tree mode
When you want to connect switches in a loop without traffic grinding to a halt, the concept to understand is spanning-tree mode. Spanning Tree Protocol (STP) prevents the endless circulation of traffic (a broadcast storm) that a loop of switches would otherwise cause.
The syntax is spanning-tree mode mode-name, in configuration mode, specifying an operating mode such as pvst.
Running spanning-tree mode pvst enables the mode that computes an independent spanning tree per VLAN, so deliberately built redundant loops in the cabling stay safe and traffic keeps flowing.
A common stumble is not knowing STP handles loops automatically, avoiding loop cabling altogether, and losing the benefits of a redundant design.
In real work, STP is indispensable groundwork for redundant network designs that keep traffic flowing through equipment failures.
🧑💻 You can type this command into the Networking pseudo terminal to try it yourself (this page itself has no interactive terminal).