RHEL5/6 Interview Questions : Network Services

1. What is the xinetd service used for?

1a. The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

2. Editing the /etc/xinetd.d/tftp file and enabling the service are the same as running the chkconfig tftp on command. True or False?

2a. True. Both of these actions have the same effect.

3. What command is used to show all services being controlled by the xinetd daemon?

3a. chkconfig xinetd –list

4. What is the main config file for the DHCP service?

4a. The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

5. Does a DHCP server allow reserved IP addresses? If so, how?

5a. Yes. Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

6. What command can you use to check the config file of the DHCP server?

6a. service dhcpd configtest

7. What port does the DHCP server listen on by default?

7a. The DHCP server listens on port 67 by default.

8. Which file shows you all the client IP addresses?

8a. The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

9. What command and options can you use to update the time?

9a. After the ntpd service is stopped, you can use the ntpdate <server> command to update/sync the time