Scan Practice Skills Exam EIGRP PT Guide

Understanding and configuring dynamic routing protocols is crucial for building robust and scalable networks. This section will guide you through the essential steps and concepts needed to excel in configuring and troubleshooting complex routing systems. Whether you are preparing for a certification or simply enhancing your skills, mastering these topics is key to ensuring efficient data transfer across diverse network environments.

Effective troubleshooting techniques and hands-on practice with various routing configurations can make the difference between success and failure in real-world network management. Through detailed explanations and practical scenarios, this guide will provide the knowledge necessary to navigate common challenges and optimize routing performance.

Preparing for network configuration challenges involves developing a strong foundation in both theoretical knowledge and practical application. By focusing on critical areas such as routing table management, protocol-specific settings, and neighbor relationships, you can strengthen your ability to address issues swiftly and accurately. This comprehensive approach will help you build the confidence needed to handle any routing-related task with ease.

Routing Protocol Configuration Overview

When preparing for a network configuration challenge, a deep understanding of routing protocols and their applications is essential. This section will provide an overview of what is involved in configuring and troubleshooting a dynamic routing protocol, emphasizing hands-on exercises and realistic scenarios. The goal is to ensure that the network behaves as expected and can scale with changes in topology and data requirements.

Understanding the Process

The process involves setting up the necessary components to ensure smooth communication between routers. Key elements like protocol settings, network topology, and neighbor relationships need to be configured correctly to avoid issues such as routing loops or lost packets. Mastering these aspects ensures that routing decisions are made efficiently, contributing to network stability and optimal performance.

What to Expect During the Setup

Expect a series of tasks that simulate real-world challenges. These might include tasks such as adjusting configurations to ensure that routers can communicate effectively, handling topology changes, and troubleshooting common issues. The key to success lies in accurately implementing the protocols while maintaining network consistency and ensuring reliability across multiple devices.

Understanding the Importance of EIGRP

Dynamic routing protocols play a crucial role in modern networking by enabling devices to automatically adjust to changes in network topology. Their primary function is to ensure that data travels along the most efficient path, adapting in real-time to network changes. The ability of these protocols to react swiftly and make intelligent routing decisions is essential for maintaining performance and stability in large-scale networks.

Why It Matters in Network Design

When building scalable networks, the choice of routing protocol can significantly impact performance. The ability to quickly converge after a network failure or topology change is key to ensuring minimal downtime. Protocols that are capable of faster convergence and more efficient route calculation, like the one discussed here, allow for smoother communication and reduce the risk of congestion or dropped packets.

Benefits in Real-World Applications

In practice, the application of these protocols helps network administrators manage complex infrastructures with ease. They provide automation for route discovery and adjustment, which significantly reduces manual intervention and the potential for human error. This is particularly important in large networks, where the dynamic nature of connections requires constant recalibration to maintain optimal performance.

Key Concepts to Master for the Exam

To successfully navigate network configuration challenges, a strong grasp of fundamental concepts is essential. Mastering these concepts ensures you can efficiently set up and troubleshoot routing systems, adapt to dynamic changes, and optimize network performance. Below are some critical areas to focus on when preparing for a routing protocol configuration task.

Critical Topics to Understand

• Routing Tables – Understanding how routers create, update, and maintain routing tables is foundational to network design.
• Convergence – The speed at which a network stabilizes after a topology change is crucial for minimizing downtime and packet loss.
• Neighbor Relationships – Establishing and troubleshooting router-to-router connections is vital for smooth operation.
• Metric Calculation – Learn how routers calculate the best path based on metrics like bandwidth, delay, and load.
• Route Redistribution – Knowing how to redistribute routing information between different protocols is critical for integrated network environments.

Advanced Techniques for Troubleshooting

• Path Selection – Understanding how the protocol selects optimal paths and troubleshooting any discrepancies is key for maintaining network efficiency.
• Fault Isolation – Being able to pinpoint issues in a network, such as routing loops or unreachable destinations, is essential for maintaining system integrity.
• Load Balancing – Ensure that network traffic is distributed evenly across multiple paths to prevent congestion and enhance performance.

Preparing Your Lab for EIGRP Practice

Before diving into network configuration and troubleshooting tasks, setting up a well-organized and efficient lab environment is crucial. This allows you to simulate real-world scenarios, test various configurations, and develop hands-on expertise. Proper preparation ensures you can easily identify issues, troubleshoot effectively, and refine your techniques in a controlled setting.

Essential Equipment and Software

• Routers and Switches – Ensure you have a sufficient number of routers and switches to create a complex, multi-router environment.
• Router Images and Simulation Software – Use tools like Cisco Packet Tracer or GNS3 to emulate devices and test configurations without needing physical hardware.
• Console Cables – These are necessary to connect your routers to a terminal for configuration and troubleshooting.
• Network Topology Designs – Prepare network diagrams that reflect real-world setups, including multiple subnets, devices, and connections.

Configuring the Lab Environment

• Basic Network Setup – Start by connecting devices, setting IP addresses, and ensuring all devices can communicate with one another.
• Enabling Routing Protocols – Configure routing protocols on your devices to ensure they can share routing information and make dynamic adjustments.
• Simulating Network Failures – Introduce issues such as link failures or topology changes to practice troubleshooting and ensure your setup can adapt to these changes.

Common EIGRP Configuration Mistakes

When setting up dynamic routing protocols, it’s easy to overlook certain details that can lead to network inefficiencies or failures. A small misconfiguration can result in routing loops, incorrect path selection, or network congestion. By understanding and avoiding common mistakes, you can ensure that your routing setup is both reliable and efficient.

One of the most frequent errors occurs during the configuration of network statements. Incorrect network definitions can prevent routers from establishing neighbor relationships or cause the protocol to ignore certain subnets. Additionally, failing to properly configure router interfaces or neglecting to enable the routing protocol on specific interfaces can lead to incomplete or incorrect routing tables.

Another common mistake is improper metric configuration. Setting inappropriate values for bandwidth, delay, or other metrics can cause suboptimal path selection, resulting in slower network performance or network instability. Misunderstanding how these values influence the routing process often leads to poor decision-making, especially when routers have multiple potential paths to choose from.

Lastly, not regularly reviewing or troubleshooting the setup after initial configuration can also lead to issues down the line. Without performing regular checks on routing tables and neighbor statuses, problems such as route flapping, missing routes, or inefficient load balancing may go unnoticed, negatively affecting the network’s performance and reliability.

Step-by-Step Guide to EIGRP Setup

Setting up a dynamic routing protocol involves several key steps that ensure smooth communication between routers and efficient route discovery. By following a methodical approach, you can ensure that all devices are properly configured to exchange routing information and adapt to network changes. Below is a step-by-step guide to successfully configure a routing protocol for a functional network environment.

Start by configuring the router interfaces with appropriate IP addresses and ensuring that all devices in the network are connected correctly. Each router should be able to communicate with the others at the basic level before proceeding with the routing protocol configuration. Once the network is physically set up, it’s time to enable the protocol on each router.

Next, enter the routing protocol configuration mode and define the network statements that will allow the protocol to advertise specific networks. These statements should match the IP address ranges that you want the router to consider. It’s essential to correctly define the interfaces involved in the routing process to ensure that the protocol can establish neighbor relationships with other routers.

After configuring the network statements, adjust the protocol settings to suit your specific requirements. This includes setting the autonomous system (AS) number and adjusting any additional settings such as hello and hold timers if necessary. These settings influence how routers communicate with each other and how quickly they adapt to network changes.

Once the basic configuration is complete, verify that the routers have formed neighbors and are exchanging routes. Use command-line tools to inspect routing tables and check for any issues such as missing routes or incorrect path selections. If everything is functioning as expected, proceed with testing the setup by introducing network changes and verifying the system’s response.

Tips for Efficient EIGRP Troubleshooting

When facing issues with routing protocols, efficient troubleshooting is essential to quickly identify and resolve problems. A systematic approach helps pinpoint issues such as missing routes, incorrect path selection, or network instability. By utilizing the right tools and focusing on key areas of the configuration, you can restore network functionality and optimize performance.

Start by checking the basic connectivity between devices to ensure there are no physical layer issues. From there, move on to inspecting protocol-specific configurations, such as the router interfaces and network statements. Misconfigured interfaces or incorrect network advertisements are common culprits that can cause issues in the routing process.

Area to Check	Common Issues	Solution
Neighbor Relationships	Missing neighbors, no hello packets	Verify interface IPs, check for mismatched hello timers or authentication settings
Routing Tables	Missing routes or incorrect paths	Check network statements, ensure proper interface configurations
Route Convergence	Slow convergence, routing loops	Adjust timers, ensure proper metric values and routing policies
Metrics	Suboptimal path selection	Check bandwidth, delay, and load values; adjust if necessary

Additionally, using diagnostic commands like “show ip route” or “show ip protocols” can provide insights into the current routing table and protocol status. These commands allow you to track down the source of the problem, whether it be in the form of missing routes, incorrect metrics, or any other inconsistencies. Regularly reviewing these outputs during the troubleshooting process will help identify discrepancies and guide you towards an efficient resolution.

Analyzing EIGRP Network Topologies

Understanding network topologies is crucial for optimizing routing performance and troubleshooting potential issues. By analyzing the structure of the network, you can determine how routers communicate, how traffic is routed, and identify areas where network performance might be improved. This insight is essential for efficient configuration and problem resolution.

Key Factors in Network Topology Analysis

• Network Design – Ensure that your network is structured to support efficient routing. This includes considering hierarchical design models such as core, distribution, and access layers.
• Redundancy – Redundant links help improve network reliability, but improper configurations can lead to unnecessary complexity and routing loops.
• Connectivity – Verify that all devices in the topology are properly connected and configured to exchange routing information.
• Scalability – Analyze the network’s ability to grow and adapt to new devices and connections without disrupting existing configurations.

Steps for Analyzing Network Topology

1. Visualize the Network – Start by creating a network diagram that reflects all routers, links, and relevant configurations. This helps identify potential issues at a glance.
2. Verify Router Connections – Ensure that routers are correctly connected to one another and that their interfaces are active and properly configured.
3. Examine Routing Tables – Review the routing tables for each router to ensure that routes are being advertised and received as expected.
4. Check for Redundancy Issues – Ensure that redundant paths are properly configured to avoid routing loops or unnecessary traffic overhead.
5. Simulate Failures – Test the network’s response to changes, such as link failures or topology changes, to evaluate its resilience and troubleshooting effectiveness.

How to Handle EIGRP Neighbors Issues

Neighbor relationships are crucial for the proper functioning of dynamic routing protocols. When routers fail to establish or maintain these relationships, it can lead to incomplete routing tables, poor network performance, or even network outages. Resolving these issues requires a systematic approach to identify the root causes and restore stable communication between devices.

Common Causes of Neighbor Relationship Failures

Several factors can prevent routers from forming successful neighbor relationships. Some of the most common issues include:

• IP Address Mismatch – If the network IPs of adjacent routers are misconfigured or incompatible, they will not be able to establish communication.
• Authentication Issues – If authentication settings are not correctly aligned between routers, they may fail to recognize each other and establish a connection.
• Incompatible Hello and Hold Timers – Mismatched timers can prevent routers from maintaining communication or forming stable neighbors.
• Physical Connectivity Problems – Broken links or incorrect cabling can also interrupt the neighbor formation process, even if the configuration appears correct.

Steps to Resolve Neighbor Issues

Follow these steps to troubleshoot and resolve issues with router neighbor relationships:

1. Check Interface Configuration – Ensure that the interfaces are properly configured with the correct IP addresses and that they are active and not administratively shut down.
2. Verify Network Statements – Make sure that the correct network addresses are advertised, and that both routers are configured to recognize the same subnets.
3. Check Authentication Settings – Ensure that authentication settings match on both sides, including passwords and authentication methods.
4. Review Timer Settings – Verify that the hello and hold timers are consistent across all routers involved in the neighbor relationship.
5. Use Diagnostic Commands – Use tools like show ip eigrp neighbors and show ip protocols to check the status of neighbor relationships and diagnose any issues with the protocol configuration.

By following these troubleshooting steps and carefully reviewing the router configurations, you can quickly resolve most issues related to neighbor relationships and ensure the stability of your dynamic routing environment.

Testing and Verifying EIGRP Configurations

Ensuring that routing configurations are correctly implemented is a critical step in maintaining a stable and efficient network. Testing and verification procedures help confirm that routers are exchanging information as expected and that the network topology is functioning properly. By systematically verifying each component of the configuration, you can quickly identify and resolve any issues that may arise.

Methods for Verifying Configuration Integrity

There are several techniques available to test and validate the routing protocol setup. These methods ensure that all configurations are aligned and functioning as intended:

• Check Neighbor Relationships – Confirm that routers can successfully establish and maintain communication with their neighbors. Use the show ip eigrp neighbors command to verify the status of all active neighbor connections.
• Verify Routing Table Entries – Inspect the routing table to ensure that all advertised routes are being received correctly. The show ip route command provides detailed information about the current routes and their origins.
• Examine Interface Configuration – Ensure that the router interfaces are configured properly with the correct IP addresses, subnet masks, and network advertisements. Use show ip interface brief to check the status of the interfaces.
• Test Connectivity – Perform basic connectivity tests using tools such as ping or traceroute to ensure that routers can communicate over the network and that routing paths are functional.
• Monitor Protocol Status – Use the show ip protocols command to review the current status of the routing protocol. This command provides insights into timers, hello intervals, and other critical parameters.

Steps for Thorough Configuration Testing

1. Verify Router ID – Ensure that each router has a unique Router ID, which is essential for routing protocol operations. This ID can be manually set or automatically determined.
2. Confirm Network Advertisements – Ensure that the correct networks are being advertised by the router. The network command should be properly configured to include the relevant subnets.
3. Check Metric Calculations – Validate the metric values used by the protocol. Incorrect metric configurations can lead to suboptimal routing decisions.
4. Test Convergence Time – Evaluate how quickly the network converges after a topology change. Faster convergence times are critical for maintaining network stability.
5. Perform End-to-End Testing – Finally, test end-to-end communication between devices on different network segments to verify that the entire routing setup is functioning as expected.

By following these verification methods and testing steps, you can confidently ensure that the routing protocol configuration is correct, and the network is optimized for performance and stability.

Advanced EIGRP Features You Should Know

While basic configuration and troubleshooting are essential, understanding the advanced features of a dynamic routing protocol can greatly enhance network efficiency and reliability. These advanced capabilities allow for more granular control over routing decisions, optimize bandwidth usage, and improve fault tolerance. Mastering these features can help network engineers design and maintain more robust and scalable networks.

Key Advanced Features

Some advanced features offer significant improvements in routing performance, flexibility, and scalability. Below are a few features worth exploring:

• Unequal Cost Load Balancing (UCLB) – This feature allows for load balancing across multiple paths, even if the paths have unequal metrics. It can be useful for optimizing network resource utilization and increasing redundancy.
• Route Summarization – Route summarization helps reduce the size of routing tables and minimizes the overhead of network updates by grouping multiple routes into a single advertisement.
• Stub Routing – Stub routing helps reduce network complexity by restricting the routes advertised to specific neighbor routers. This is particularly useful in branch offices or remote sites with limited connectivity requirements.
• Reliable Transport Protocol (RTP) – RTP ensures that updates and control messages are reliably delivered between routers, which enhances the overall stability of the network.

Advanced Configuration Example

To implement some of these advanced features, specific configuration commands are required. Below is an example of how you can configure unequal cost load balancing:

Step	Configuration Command	Description
1	router eigrp 100	Enter router EIGRP configuration mode with the autonomous system (AS) number.
2	variance 2	Enable unequal cost load balancing, setting the variance to 2 (which allows for up to two times the metric of the least cost path).
3	network 192.168.1.0	Define the network you wish to advertise in the routing protocol.

By enabling this feature, the router will consider paths with up to twice the metric of the lowest path for load balancing. This can improve bandwidth usage and reduce the chances of network congestion.

Understanding and implementing these advanced features can significantly improve network performance, fault tolerance, and scalability. Mastering them will allow you to design more efficient and resilient routing configurations tailored to specific network needs.

Time Management During the Exam

Effective time management is crucial when facing any type of assessment. Properly allocating your time ensures that you can address all areas of the test without feeling rushed or missing key questions. A well-organized approach helps reduce anxiety, improve performance, and allows for a thorough review of your answers.

One of the first steps to managing your time effectively is understanding the format and requirements of the test. Knowing how many questions you need to complete and the time allocated can help you pace yourself. Here are some tips to make the most of the available time:

• Prioritize the Easy Questions – Begin with the questions you find the most straightforward. This builds confidence and ensures that you secure those points early on.
• Allocate Time for Review – Always leave a few minutes at the end to review your answers. This ensures that you catch any mistakes or missed details.
• Don’t Get Stuck on One Question – If you encounter a difficult question, move on and come back to it later. Spending too much time on a single question can cause you to fall behind.
• Track Time Carefully – Set a timer or periodically check the clock to keep track of how much time you have left. Divide your time evenly across sections or questions, adjusting as needed.

By applying these strategies, you can manage your time effectively, ensuring you give yourself the best chance to complete the assessment thoroughly and confidently. Remember that maintaining a steady pace and staying organized are keys to success in any timed task.

How to Avoid Common EIGRP Pitfalls

When working with advanced routing protocols, it’s easy to overlook certain configurations or make assumptions that lead to issues down the line. By understanding the common mistakes and pitfalls, you can avoid frustration and ensure a smooth implementation. Many problems arise from misconfigurations or a lack of attention to detail in the setup process. Awareness and preparation are key to preventing these challenges.

1. Misconfiguring Network Interfaces

One of the most frequent issues occurs when interfaces are incorrectly configured. This can happen when network interfaces are mistakenly placed in the wrong area of the configuration or when IP addresses are improperly assigned. To avoid this:

• Double-check the interface configurations, ensuring that each interface is correctly linked to the intended network.
• Verify IP addressing to make sure that each device is operating within the right subnet range.
• Review subnet masks carefully to ensure proper network segmentation.

2. Ignoring Authentication Settings

Failing to implement proper authentication for routing protocol exchanges can lead to security vulnerabilities and disrupted communications. Neglecting this step can result in unauthorized routers joining the network or failure in route propagation. To safeguard your network:

• Always configure authentication to prevent unauthorized devices from participating in routing exchanges.
• Use strong encryption methods to secure communication between routers.
• Regularly verify authentication settings to ensure they are up-to-date.

By being mindful of these common pitfalls and applying best practices, you can maintain a stable, efficient network environment. Proper configuration, careful verification, and attention to detail can prevent most issues from arising in the first place.

Practical Exercises to Reinforce Knowledge

Hands-on exercises are essential for consolidating theoretical knowledge and developing a deep understanding of routing protocols and network configurations. While theoretical study provides the foundation, practical experience enables you to apply concepts in real-world scenarios, troubleshoot effectively, and adapt to changing network conditions. Engaging in practical tasks helps reinforce learning and prepares you for real-life situations.

1. Setting Up a Simple Routing Network

Begin by configuring a small network with multiple routers and simulate various routing scenarios. This exercise will help you grasp the basics of routing configuration, including setting up interfaces, assigning IP addresses, and enabling routing protocols. It will also allow you to test connectivity between routers and troubleshoot any issues that arise.

2. Configuring and Verifying Routing Tables

Once your network is set up, work on configuring routing tables to direct traffic between different network segments. Use different routing protocols and observe how the routing tables evolve. This task will deepen your understanding of how routers calculate the best paths and manage routing information.

3. Simulating Failure and Troubleshooting

Simulate network failures, such as link outages or incorrect routing updates, and practice troubleshooting the issues. This will help you learn to identify common problems, use diagnostic commands, and restore network functionality quickly. It’s essential to get familiar with diagnostic tools like ping, traceroute, and show commands to verify the status of network interfaces and routing tables.

4. Advanced Configuration Scenarios

For more advanced exercises, try configuring dynamic routing with complex topologies. This includes implementing features like route summarization, load balancing, and adjusting metrics. These tasks will sharpen your ability to work with more intricate network setups and understand their implications.

5. Working with Network Simulation Tools

Utilize network simulation software to build and test larger network topologies without the need for physical hardware. Tools like GNS3 or Packet Tracer allow you to experiment with various configurations, observe real-time data flow, and simulate network behavior in a controlled environment.

Suggested Exercise Table

Exercise	Goal	Expected Outcome
Simple Router Setup	Configure basic routing and verify connectivity	Routers successfully communicate with each other
Routing Table Configuration	Set up routing protocols and verify routing tables	Correct routes are selected for optimal data flow
Network Failure Simulation	Simulate a link failure and troubleshoot the issue	Network functionality is restored after identifying the cause
Advanced Feature Implementation	Implement advanced routing configurations like load balancing	Network traffic is efficiently balanced across multiple paths

By consistently engaging in these exercises, you’ll not only solidify your understanding of network configurations but also gain the confidence needed to handle a wide range of networking challenges in real-world environments.

Reviewing Key Networking Topics for Assessment

Before attempting any comprehensive assessment related to routing protocols, it’s crucial to review and familiarize yourself with the key concepts and configurations that are likely to appear. Understanding these critical topics will not only help you perform better but also ensure a deeper comprehension of the core principles and practical aspects of routing technologies. By focusing on the most important areas, you can approach the assessment with confidence and precision.

Essential Topics to Review

Below are the fundamental areas to focus on in order to prepare for the networking assessment:

• Network Topology Design – Understanding how different network elements are connected and how traffic is routed across these elements is crucial. Study various network designs, including hub-and-spoke, full mesh, and point-to-point topologies.
• Routing Protocols and Metrics – Learn how routing protocols work, including their metrics and decision-making processes. Focus on how protocols select the best path for routing traffic based on parameters such as bandwidth, delay, and reliability.
• Routing Tables and Path Selection – Review how routing tables are populated and how routers decide the most efficient path. Familiarize yourself with the concept of routing loops, path costs, and route summarization.
• Advanced Routing Features – Understand advanced features such as route redistribution, filtering, and policy-based routing. Be prepared to explain and configure these features in practical scenarios.
• Troubleshooting Techniques – Know how to troubleshoot routing issues. This includes verifying configuration settings, using diagnostic commands, and analyzing routing table inconsistencies or packet flow problems.

Common Configuration Scenarios

Review the most common configuration scenarios that often appear in assessments. These include:

• Configuring static routes and dynamic routing protocols
• Configuring access control lists (ACLs) for routing security
• Implementing redundancy protocols to ensure network availability
• Configuring and verifying path selection, such as Equal-Cost Multi-Path (ECMP)
• Optimizing routing efficiency through features like route summarization and filtering

Key Commands for Verification

It’s essential to be familiar with the commands used to verify configurations and troubleshoot network issues. Some of the most important commands include:

• show ip route – Displays the routing table and the routes in use.
• show ip protocols – Displays the configuration and status of active routing protocols.
• show interfaces – Provides detailed information about interface statuses and metrics.
• ping and traceroute – Used to test network connectivity and trace the path taken by data packets.

By revisiting these core areas and practicing relevant configurations, you’ll be well-prepared to tackle any challenges that may arise during a comprehensive networking assessment.

Final Tips for Success on the Exam

As you approach the final stages of your preparation, it’s important to solidify your understanding and refine your approach. Proper planning, focus, and a calm mindset will play a crucial role in ensuring success. With the right strategies and mindset, you can approach the assessment confidently and perform at your best.

Stay Organized and Focused

Before tackling any task, ensure that you have a clear roadmap of what needs to be done. Organize your study materials, prioritize topics based on difficulty, and break down your preparation into manageable steps. A focused study plan will help you stay on track and avoid feeling overwhelmed.

• Prioritize Key Topics: Focus on the most critical areas that are frequently tested. Understanding these topics will provide a strong foundation for addressing the majority of questions.
• Time Management: During the assessment, manage your time effectively. Allocate enough time for each section, leaving room for review at the end. Avoid spending too much time on any single question.
• Practice Under Test Conditions: Simulate the testing environment by timing yourself and practicing with real-world scenarios. This will help you get comfortable with the format and improve your efficiency under time constraints.

Master the Art of Troubleshooting

Being able to quickly identify and resolve issues is a key part of your preparation. Whether it’s diagnosing configuration errors or troubleshooting routing problems, developing a systematic approach to problem-solving will help you handle unexpected situations during the assessment.

• Use Logical Thinking: When faced with a problem, approach it methodically. Break down the issue step by step and test each potential cause.
• Understand Commands and Outputs: Familiarize yourself with common diagnostic commands and their outputs. This will allow you to efficiently troubleshoot and verify configurations during the assessment.

Stay Calm and Confident

Confidence is key when it comes to any assessment. Trust in your preparation and remain calm throughout the process. If you encounter a difficult question, take a deep breath, move on to the next one, and return to it later if needed. Staying composed will allow you to think clearly and make informed decisions.

By following these tips and maintaining a positive attitude, you’ll increase your chances of success and leave the assessment feeling confident in your abilities. Good luck!