Free CCNA | Analyzing STP | Day 20 Lab | CCNA 200-301 Complete Course
Welcome to Jeremy’s IT Lab
In this section, Jeremy introduces his IT Lab and encourages viewers to subscribe and share the videos. He also mentions a practice lab that can be downloaded from the video description.
Introduction and Subscription
- Jeremy welcomes viewers to Jeremy's IT Lab.
- He mentions that the course is free and complete for the CCNA.
- Viewers are encouraged to subscribe, like, comment, and share the videos.
- A practice lab is available for download from the video description.
Packet Tracer Practice Lab
Jeremy recommends using Boson's NetSim for CCNA for more labs like these. He explains that NetSim is a network simulator similar to Packet Tracer but with additional guided labs.
Using Boson's NetSim
- Jeremy recommends using Boson's NetSim for CCNA.
- He describes it as a network simulator better than Packet Tracer.
- NetSim includes guided labs to help with hands-on practice and understanding of exam topics.
- Jeremy used NetSim himself when studying for certifications.
Lab Instructions
Jeremy provides instructions for the lab exercise. He explains how to turn off link lights in Packet Tracer and suggests reviewing lecture videos if any concepts have been forgotten.
Lab Instructions
- Link lights should be turned off in Packet Tracer to prevent visibility of forwarding or blocking states on interfaces.
- To turn off link lights, go to Options > Preferences > Disable "Show Link Lights".
- Review lecture videos if any concepts such as bridge ID or root cost have been forgotten before attempting the exercise.
Spanning Tree Port Roles
This section covers identifying the root bridge and determining spanning tree port roles using CLI commands in Packet Tracer.
Identifying the Root Bridge
- The first part of the lab is similar to the practice quiz questions from the lecture video.
- The root bridge needs to be identified by comparing bridge priorities and MAC addresses.
- In this case, SW3 has the lowest priority (24577) and becomes the root bridge.
Determining Port Roles
- All interfaces on SW3 are designated ports since it is the root bridge.
- CLI commands can be used to confirm spanning tree information.
Root Ports
This section focuses on finding and labeling root ports for each switch in the topology. Tiebreakers such as root cost and neighbor bridge ID are used.
Finding Root Ports
- Each switch in the topology should have a single root port.
- The interface with the lowest root cost becomes the root port.
- SW1's F0/4 interface is connected to SW3 with a cost of 27, while F0/3 or F0/4 have a cost of 19.
- The tiebreaker is neighbor bridge ID, which doesn't provide a clear winner.
- The final tiebreaker is neighbor switch's port ID, where F0/1 has a lower port ID than F0/4. Therefore, SW1's F0/4 interface becomes the root port.
Remaining Port Roles
This section covers determining designated and non-designated ports in each remaining collision domain based on root costs.
Designating Ports
- Two obvious non-designated ports are SW1's F0/3 (connected to the root bridge) and SW2's F0/3 (connected directly to SW3).
- To determine designated ports, compare root costs between switches.
- SW2 has a lower root cost (8 via G0/1) compared to SW1 (19 via F0/4).
- Therefore, SW2's F0/1 and F0/2 interfaces will be designated ports.
Conclusion
Jeremy concludes the lab exercise by summarizing the designated and non-designated ports for each switch in the topology.
Summary
- SW3: All interfaces are designated ports.
- SW1: F0/4 is the root port, F0/1 and F0/2 are non-designated ports.
- SW2: G0/1 is the root port, F0/1 and F0/2 are designated ports.
- SW4: G0/1 is a designated port, G0/2 is the root port.
Understanding VLANs and Spanning Tree
In this section, the speaker explains the concept of VLANs and provides an overview of the spanning tree protocol.
VLAN Information
- The output of the command "SHOW SPANNING-TREE" displays information about VLANs on switches.
- Each VLAN can have separate information listed.
- Filtering the output with a specific VLAN number is possible using the command "SHOW SPANNING-TREE VLAN 1".
- In this case, there is only one VLAN, so it doesn't affect the output.
Spanning Tree Protocol
- The spanning tree enabled protocol used is IEEE (classic mode).
- Two main sections in the output: Root ID and Bridge ID.
- Root ID provides information about the root bridge of the spanning tree.
- Bridge ID lists information about this switch's own details.
- SW3 is identified as the root bridge in this case.
- Timers related to spanning tree are mentioned but not explained in detail.
Examining Spanning Tree Output
This section focuses on analyzing the output of "SHOW SPANNING-TREE" command for a specific switch.
Interface Details
- The bottom part of the output lists each interface participating in spanning tree.
- Information provided includes role, status, cost, interface ID, and interface type.
Expected Behavior for Root Bridge
- As SW3 is identified as the root bridge, all interfaces should be designated ports and forwarding.
- The displayed output confirms that all interfaces meet these expectations.
Additional Commands
- "SHOW SPANNING-TREE DETAIL" provides similar information to "SHOW SPANNING-TREE" but with more details.
- "SHOW SPANNING-TREE SUMMARY" lists each VLAN and shows how many interfaces are in each STP state.
Analyzing Spanning Tree Output for SW1
This section focuses on analyzing the output of "SHOW SPANNING-TREE" command for SW1.
Port Status
- F0/4 is identified as the root port and is in a forwarding state.
- Other interfaces are blocking, referred to as "alternate" instead of non-designated.
Root ID and Bridge ID
- The root ID section shows information about SW3 (root bridge).
- The bridge ID section displays information specific to SW1.
Analyzing Spanning Tree Output for SW2
This section focuses on analyzing the output of "SHOW SPANNING-TREE" command for SW2.
Port Status
- F0/1 and F0/2 interfaces connected to SW1 are designated ports and in a forwarding state.
- These connections are currently disabled due to blocking by SW1.
- F0/3 is blocking, and G0/1 is the root port.
Cost Calculation
- The displayed cost represents only the cost of this interface, not the total root cost.
- To view the total root cost, use the command "SHOW SPANNING-TREE DETAIL".
Successful Spanning Tree Topology Calculation
This section concludes the analysis of spanning tree output by confirming successful topology calculation.
Interface Roles
- G0/1 on SW4 is designated, while G0/2 serves as the root port.
Boson NetSim Lab Preview: Spanning Tree
In this section, the speaker discusses why Boson NetSim for CCNA does not include spanning tree labs but emphasizes its importance in hands-on practice.
Exam Topics List Comparison
- The CCNA exam topics list does not mention configuring spanning tree.
- Boson NetSim for CCNA aligns with the exam topics list, hence no spanning tree labs are included.
- However, the CCNP ENCOR exam topics list includes configuring and verifying spanning tree protocols.
Importance of Hands-on Practice
- The speaker believes it is still essential to gain hands-on practice in the CLI for observing and configuring spanning tree.
Exploring Spanning Tree Labs in CCNP ENCOR
This section discusses the availability of spanning tree labs in the CCNP ENCOR exam topics list.
Multiple Spanning Tree Labs
- The CCNP ENCOR exam topics list includes several labs related to spanning tree protocols.
- One lab titled "Spanning Tree Protocol" is selected for further exploration.
The remaining part of the transcript does not contain relevant information for note-taking purposes.
New Section
In this section, the speaker introduces the terms "access switch" and "distribution switch" and explains how hosts connect to access switches, which then connect to distribution switches. The speaker also mentions a command to display the spanning tree for VLAN 1.
Understanding Access and Distribution Switches
- Hosts connect to access switches, which in turn connect to distribution switches.
Displaying Spanning Tree for VLAN 1
- On P1DSW1, use the command
SHOW SPANNING-TREE VLAN 1 DETAILto view the spanning tree for VLAN 1.
- Answer question A: Which spanning tree is VLAN 1 executing? The answer is "ieee compatible Spanning Tree Protocol".
- Answer question B: What are the priority, sys-id, VLAN number, and MAC address? The bridge identifier has a priority of 24576 (sysid 1) and a MAC address.
- Answer question C: Why are there no root ports? Because this switch is the root bridge, all interfaces on it must be designated ports.
- Answer question D: Why are there no blocked ports for VLAN 1? As the root bridge, all ports should be designated and in a forwarding state.
- Answer question E: What is the timer value for sending BPDUs (bridge protocol data units)? The configured hello time is every 2 seconds.
- Answer question F: What is the maximum age for a BPDU? It is set at 20 seconds.
- Answer question G: What is the value of the forward delay timer? It is set at 15 seconds.
New Section
In this section, the speaker concludes the lab preview and mentions additional lab solutions available in Boson NetSim for CCNA.
Conclusion and Lab Solutions
- The speaker highlights that there is one more step to the lab and mentions that lab solutions are available to review different outputs.
- Boson NetSim for CCNA offers guided labs for various exam topics, including network fundamentals, network access, IP connectivity, IP services, and security fundamentals.
- The speaker recommends getting a copy of NetSim for CCNA and provides a link in the video description.
- The video ends with a call to action: subscribe to the channel, like the video, leave a comment, and share it.