Skip to content

32 DNS Service Additional Zones

  • Configuring Additional DNS Clients
    • The existing DNS server is hosted on Ubuntu and resolves internal domains.
    • The goal is to allow other machines, like the internal Kali system, to use this DNS service.
    • DNS settings are updated in Kali’s /etc/resolv.conf file to point to the Ubuntu DNS server (192.168.8.2).
  • Verifying DNS Resolution on Kali
    • Adding nameserver 192.168.8.2 to resolv.conf directs DNS queries to the Ubuntu machine.
    • Testing with nslookup www.ncaecybergames.org verifies the resolution.
    • The browser successfully accesses www.ncaecybergames.org, confirming DNS functionality.
  • Expanding DNS Records for Additional Services
    • The DNS server currently resolves only www.ncaecybergames.org.
    • To extend functionality, more records must be added for other services like the scoreboard.
    • The scoring server is externally hosted (172.20.0.1), and a new subdomain (score.ncaecybergames.org) is assigned to it.

  • Updating the Forward Lookup Zone

    • The forward lookup file (/etc/bind/zones/forward.ncaecybergames.org) is modified.

    • A new A record is added:

      score IN A 172.20.0.1

    • The serial number in the file is incremented before saving.

    • Restarting and Testing the Updated DNS Service
    • The DNS service is restarted using sudo systemctl restart named.
    • Running nslookup score.ncaecybergames.org confirms that it now resolves to 172.20.0.1.
    • Accessing score.ncaecybergames.org in a browser shows the scoring page, confirming success.
    • Implementing Reverse DNS for Scoreboard Domain
    • Reverse DNS allows resolving an IP back to a domain name.
    • The /etc/bind/named.conf.default-zones file lacks a record for the 172.20.0.x network.
    • A new reverse zone entry is created for 172.20 using the arpa format.
    • Modifying the Reverse Lookup Zone File

    • The file /etc/bind/zones/reverse.ncaecybergames.org is updated to include:

      1.0 IN PTR score.ncaecybergames.org.

    • The serial number is incremented, and the file is saved.

    • Applying Reverse DNS Changes
    • The DNS service is restarted again: sudo systemctl restart named.
    • Running nslookup 172.20.0.1 confirms the reverse lookup now maps to score.ncaecybergames.org.
    • Final Testing and Browser Validation
    • The updated DNS server now resolves both forward (score.ncaecybergames.org → 172.20.0.1) and reverse (172.20.0.1 → score.ncaecybergames.org).
    • Other devices on the network can now use the configured DNS service to resolve names.
    • A browser test confirms seamless access to the scoreboard using its domain instead of an IP address.

Next in Playlist: 33 DNS Service Through The Router