LPI Linux Certification in a Nutshell, 2nd Edition

Network Troubleshooting (Topic 2.214)

Review Questions

1. What is the purpose of the search keyword in the /etc/resolv.conf file?

2. You know that your DNS server is accepting requests. However, several hosts are consistently trying to connect to the wrong email server. Clearly, these hosts are mapping the hostname to the wrong IP address. You have checked the /etc/resolv.conf files on each of these hosts, and they list your DNS server and domain. What is the most likely cause of this problem?

3. What is the most likely location of the file that configures network interfaces in a Debian-based system?

4. What command will best help you learn what has occurred during the boot process?

5. You are currently logged in to a Linux system that has three interfaces. You wish to send a large number of ping packets in a short amount of time out of the third interface to a system named jacob. What command would you issue?

6. A DNS server is currently responding to requests very slowly. As a result, your query using the host command times out before the DNS server can respond. What option to the host command can you specify to make your system wait indefinitely for the DNS server to respond?

Answers

1. The search keyword has the resolver search the specified domain rather than the default domain. Sometimes this keyword is necessary because the host thinks that there is no default domain.

2. The /etc/hosts file probably contains incorrect IP address information for the email server. The /etc/hosts file overrides DNS and NIS ...