LPI Linux Certification in a Nutshell, 2nd Edition

DNS (Topic 2.207)

Review Questions

1. You wish to use the dig command to query the server named dns1.company.com to see whether the PTR record for the system named adam exists. What would this command look like?

2. Consider the following text:

   zone "." {
           type hint;
           file "/etc/bind/db.root";
   };

   What is the purpose of this entry, and what file does this entry belong in?

3. You have been given a new host to enter into the forward DNS zone. This hostname is for the Web server. The host's IP address is 192.168.2.5, and the host's name is www.company.com. Write in the entry you would create in the DNS server's forward zone file for this server.

4. You wish to establish a chroot jail for your DNS server. You are using BIND. Why is it necessary to copy or move directories such as the /etc/bind directory to another, special location on the hard drive?

5. Your system ships with the BIND 8 dnskeygen command, rather than the BIND 9 dnssec-keygen command. Both have the same function. Using dnskeygen or its equivalent, what command would you issue to create a public-key pair with the size of 1024 bits that can be used only for authentication for the mycompany.com domain?

6. You are in an interactive nslookup session. What command would you issue to switch from the default nameserver to dns2.company.com?

Answers

1. Enter:

   # dig @dns1.company.com PTR adam

2. The text primes the DNS server to look for root servers. This entry belongs in the named.conf file.

3. Create the following entry in the DNS server's forward zone file:

   IN A www 192.168.2.5 ...