DNS Configuration and Troubleshooting

This repository demonstrates configuring and troubleshooting DNS settings to ensure proper network connectivity and domain resolution.

Skills Covered:

• Setting up DNS records and zones
• Troubleshooting DNS errors
• Configuring forward and reverse lookup zones
• Ensuring DNS resolves domain names correctly across the network

Key Steps:

1. Set up DNS zones for internal and external network resolution.
2. Configure forward lookup zones for domain name resolution.
3. Troubleshoot common DNS errors using tools like nslookup.
4. Verify DNS server settings to ensure proper domain resolution.

Please refer to the DNS Configuration Guide for step-by-step instructions.

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Resources:

• DNS Setup Documentation
• DNS Troubleshooting Tools

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Domain Name System (DNS) Configuration and Management

Domain Name System (DNS) makes the internet more user-friendly by translating readable domain names (e.g., example.com) into IP addresses that computers use to locate and communicate with each other. Essentially, DNS functions as the internet’s "phonebook," directing users to the correct website when they type a web address. This project will cover the essential steps for configuring DNS using Microsoft Azure and other network tools.

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Technologies and Operating Systems Used

Technologies Used

• Remote Desktop
• Microsoft Azure

Operating Systems Used

• Windows 10
• Windows Server 2022

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Definitions

• Ping: A network tool that tests the reachability of a host on an IP network.
• Nslookup: A tool for mapping IP addresses to domain names and troubleshooting DNS configurations.
• Ipconfig: Displays and manages network IP configurations, including IP addresses, subnet masks, and DNS servers.

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Prerequisites

Before starting, ensure that:

1. Virtual Machines: The virtual machines for DNS configuration (e.g., Domain Controller on Windows Server 2022 and client on Windows 10) should be in the same resource group and virtual network.
2. Static NIC and Matching DNS: The NIC of the Domain Controller is set to static, and the client DNS matches the Domain Controller DNS. Configure these settings in Azure.

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DNS Configuration Steps

1. A Record Configuration

1. Login to Domain Controller and Client: Access DC-1 and Client-1 as (username)-admin.

2. Test DNS Connection on Client-1:

   • Open PowerShell as admin.
   • Run nslookup mainframe to test DNS resolution. Expected: It won’t work initially.

3. Create A Record on Domain Controller:

   • On DC-1, open DNS Manager.
   • Navigate to Forward Lookup Zone > Your Domain.
   • Right-click, select New Host (A).
   • Enter mainframe as the hostname and the IP address of DC-1.
   • Check the first box below to complete the setup.

4. Verify DNS Resolution on Client-1:

   • Back on Client-1, run ping mainframe in PowerShell to confirm connectivity.

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2. Local DNS Cache

1. Update DNS Record on Domain Controller:

   • Edit the mainframe IP address on DC-1 to 8.8.8.8.

2. Test Cache Resolution on Client-1:

   • Run ping mainframe again; it won’t work as the cached DNS is outdated.

3. Clear Client-1 DNS Cache:

   • Use ipconfig /displaydns and then ipconfig /flushdns to clear the cache.

4. Re-test DNS Resolution:

   • Run ping mainframe again, and observe the updated IP address.

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3. CNAME Record Setup

1. Create CNAME Record on Domain Controller:

   • On DC-1, go to the DNS Manager and select New Alias (CNAME).
   • In the Alias name box, type search.
   • Enter www.google.com in the FQDN box. (Example purpose only.)

2. Verify CNAME Resolution on Client-1:

   • Back on Client-1, run ping search and nslookup search to confirm connectivity to www.google.com.

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Resources to Learn DNS in Depth

For a deeper understanding of DNS, consider exploring resources such as Cloudflare's DNS Learning Center.

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