> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Demo Setting Up DNS Server > This guide demonstrates how to configure a multi-node DNS setup with two nameservers and one webserver acting as a client. In this guide, we will demonstrate how to configure a multi-node DNS setup consisting of two nameservers and one webserver that also acts as a client. The configuration details are as follows: • node-01: Primary nameserver\ • node-02: Secondary nameserver\ • node-03: Webserver running an application (and acting as a client) Below is an illustration of the multi-node DNS setup: ![The image illustrates a multi-node DNS setup with three nodes: a primary nameserver, a secondary nameserver, and a web nameserver, along with a client icon.](https://kodekloud.com/kk-media/image/upload/v1752873237/notes-assets/images/Demystifying-DNS-Demo-Setting-Up-DNS-Server/multi-node-dns-setup-illustration.jpg) *** ## Primary Nameserver Setup (node-01) Begin by installing and configuring BIND9 on node-01, which will serve as the primary nameserver. ### 1. Install and Start BIND9 Start the BIND9 service: ```bash theme={null} sudo systemctl start bind9 ``` ### 2. Configure the Zone File Edit the zone configuration file (typically `named.conf.local`) to specify the zone information. In this example, our domain is `multinode.kodekloud.lab` and its zone file is stored in `/etc/bind`. The configuration should indicate that node-01 is the primary (master) server for the zone: ```plaintext theme={null} zone "multinode.kodekloud.lab" { type master; file "/etc/bind/db.multinode.kodekloud.lab"; }; ``` Gather the IP addresses for node-01 and node-02 before updating the zone file. These IP addresses will be used within the zone file. ### 3. Verify IP Addresses Run the following commands to check the IP addresses of node-01 and node-02: ```bash theme={null} # Starting the named service if not already running sudo systemctl start named # Editing configuration and zone file sudo vi /etc/bind/named.conf.local sudo vi /etc/bind/db.multinode.kodekloud.lab # Checking IP addresses: ping node01 ping node02 ``` Example output for node01: ```bash theme={null} PING node01 (192.5.84.8) 56(84) bytes of data. 64 bytes from node01 (192.5.84.8): icmp_seq=1 ttl=64 time=0.029 ms ``` And for node02: ```bash theme={null} PING node02 (192.5.84.10) 56(84) bytes of data. 64 bytes from node02 (192.5.84.10): icmp_seq=1 ttl=64 time=0.035 ms ``` ### 4. Create the Zone File Create the file `/etc/bind/db.multinode.kodekloud.lab` with the following content. This file sets the Start of Authority (SOA) record, NS records, and A records for node01, node02, and node03: ```plaintext theme={null} $TTL 604800 @ IN SOA node01.multinode.kodekloud.lab. admin.multinode.kodekloud.lab. ( 1 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL @ IN NS node01.multinode.kodekloud.lab. @ IN NS node02.multinode.kodekloud.lab. node01 IN A 192.5.84.8 node02 IN A 192.5.84.10 node03 IN A 192.5.84.12 ``` ### 5. Restart and Verify After saving the zone file, restart the BIND9 service: ```bash theme={null} sudo systemctl reload bind9 ``` You can test the DNS resolution by querying the domain using the local nameserver: ```bash theme={null} # Test resolution using ping ping node02 ping node03 # Querying with dig dig @localhost multinode.kodekloud.lab ``` This should return the SOA along with the NS records, confirming that node-01 is correctly serving as the primary nameserver. *** ## Secondary Nameserver Configuration (node-02) Next, configure node-02 as the secondary (slave) nameserver. ### 1. Install BIND9 on node-02 SSH into node-02 and start the BIND9 service: ```bash theme={null} ssh node02 sudo systemctl start bind9 ``` ### 2. Confirm the Primary Server's IP From node-02, verify the IP address of node-01: ```bash theme={null} ping node01 ``` ### 3. Configure the Secondary Zone Edit the `named.conf.local` file on node-02 to declare it as a secondary nameserver. Use node-01's IP (192.5.84.8) as the master: ```plaintext theme={null} zone "multinode.kodekloud.lab" { type slave; file "/var/cache/bind/db.multinode.kodekloud.lab"; masters { 192.5.84.8; }; }; ``` Save the file and reload BIND9: ```bash theme={null} sudo systemctl reload bind9 ``` ### 4. Configure Zone Transfer on the Primary (node-01) Ensure that the `named.conf.options` file on node-01 allows transfers to node-02. An example configuration: ```plaintext theme={null} options { directory "/var/cache/bind"; allow-transfer { 192.5.84.10; }; recursion yes; allow-recursion { any; }; listen-on { any; }; }; ``` Reload the service after making changes: ```bash theme={null} sudo systemctl reload bind9 ``` ### 5. Test the Secondary Setup Verify node-02's configuration by querying for zone data: ```bash theme={null} # Query using dig on node-02 itself dig @localhost multinode.kodekloud.lab # Test full zone transfer using AXFR if permitted dig @192.5.84.10 multinode.kodekloud.lab AXFR ``` If the zone transfer is successful, node-02 should return all the zone records. *** ## Webserver (node-03) Configuration Now, configure node-03 as the webserver and set it up to work with DNS. ### 1. Set Up Nginx on node-03 SSH into node-03, install Nginx, and start the service: ```bash theme={null} ssh node03 sudo systemctl start nginx curl localhost ``` A successful response should display the default Nginx welcome page. ### 2. Add a CNAME Record for the Webserver Update the zone file on the primary nameserver (node-01) by adding a CNAME record for the webserver. SSH into node-01 again and open the zone file `/etc/bind/db.multinode.kodekloud.lab` to include the following record: ```plaintext theme={null} $TTL 604800 @ IN SOA node01.multinode.kodekloud.lab. admin.multinode.kodekloud.lab. ( 1 ; Serial 604800 ; Refresh 86400 ; Retry 2419200 ; Expire 604800 ) ; Negative Cache TTL @ IN NS node01.multinode.kodekloud.lab. @ IN NS node02.multinode.kodekloud.lab. node01 IN A 192.5.84.8 node02 IN A 192.5.84.10 node03 IN A 192.5.84.12 www IN CNAME node03.multinode.kodekloud.lab. ``` After saving the updated file, reload BIND9: ```bash theme={null} sudo systemctl reload bind9 ``` ### 3. Update DNS Settings on node-03 On node-03, update the `/etc/resolv.conf` file to use node-01’s IP as the primary nameserver. An example `resolv.conf` might look like: ```plaintext theme={null} search us-central1-a.c.kk-lab-prod.internal c.kk-lab-prod.internal google.internal nameserver 172.25.0.1 options ndots:0 ``` ### 4. Verify DNS Resolution Finally, validate the full setup on node-03 by running: ```bash theme={null} curl www.multinode.kodekloud.lab ``` A successful output displaying the Nginx welcome page HTML confirms that the DNS resolution across both nameservers is working correctly. *** Through these detailed steps, you have successfully set up a multi-node DNS configuration with a primary nameserver (node-01), a secondary nameserver (node-02), and a webserver (node-03) hosting an Nginx service with a CNAME record pointing to it. This setup ensures reliable DNS resolution across your multi-node environment.