Test your basic knowledge |

RHCSA

Subjects : certifications, it-skills, rhcsa

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Does a DHCP server allow reserved IP addresses - If so - how?
A swap is scratch space on your file system used as virtual memory. A swap can be created as a partition or a device file.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
A large warning message appears indicating that the key doesn't match the host you are connecting to. You have to remove the key/host pair from the known_hosts file to proceed.
createrepo

2. What command can be used to easily list all the options in the FTP main config file?
The -t nfs option is used with the mount command to mount NFS resources.
A virtual host is a way of hosting multiple sites using a single IP address.
chkconfig sshd off
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

3. What is NAT - How is it used?
A large warning message appears indicating that the key doesn't match the host you are connecting to. You have to remove the key/host pair from the known_hosts file to proceed.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
Network address translation (NAT) maintains a table that allows the use of multiple internal IP addresses to a multiple public IP address (called address translation). It can also be used for one-to-one or one-to-many relationships as well.

4. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
You should never use the -U option because it erases the prior kernel when updating. This leaves you with no fallback kernel should your system not boot properly.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The htpasswd command can be used to password-protect a web page.
getsebool -a | grep http

5. What command and option do you use to view the description of Boolean values?
semanage boolean -l
lvdisplay
You can use the remove or erase options with yum to remove a package.
This command sets the eth1 interface to have a static IP address of 172.168.1.100 with a netmask of 255.255.255.0.

6. What command can you use to create a new SSL certificate?
halts the system
The two main config files are master.cf and main.cf.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

7. What does virsh reboot Client04 do?
Use the yum groupinstall command to install multiple packages in a single group at once.
This command reboots virtual guest Client04.
A large warning message appears indicating that the key doesn't match the host you are connecting to. You have to remove the key/host pair from the known_hosts file to proceed.
By default - Squid runs on port 3128.

8. Which version of SSH should you use?
Version 2 is the latest and most secure version of SSH.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
This chapter described tdbsm and smbpasswd back-end authentication.
The htpasswd command can be used to password-protect a web page.

9. What command (and options) can be used to create a user named George with the description "Jr Admin"?
useradd -c "Jr Admin" George
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
chkconfig xinetd --list
The ping command can be used to verify connectivity to another host.

10. What is the name of the package used to install an FTP?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The three utilities are: route - ping - and nslookup.
The vsftpd package is used to install an FTP server.
The four types of DNS servers are master - slave - caching-only - and forwarding.

11. What command can you use to query information from the kernel about RAID arrays?
cat /proc/mdstat
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The anonymous_enable=YES option in the main config file allows anonymous uploads.

12. Do you need to write changes to the disk when using the parted command? What about fdisk?
rpcbind service
When you exit the parted utility - all your changes are automatically written to disk. With the fdisk command - you need to manually write your changes to disk for them to take effect.
chkconfig xinetd --list
A user's home directory is created under the /home directory.

13. What options with the yum command would you use to remove a package?
You can use the remove or erase options with yum to remove a package.
Use the yum groupinstall command to install multiple packages in a single group at once.
generates errors under Red Hat Enterprise Linux 6
Typing the mail or mutt command allows you to read mail from the command line.

14. How can you verify the status of the SSH service after the system has booted?
load balancing and redundancy benefits
service sshd statuts
The print option is used with both the fdisk and parted commands to display the current partition tables.
For Apache to run a secure site - the mod_ssl package is required to be installed.

15. To export directories as resources - what file needs to be edited?

16. What command can you use to change the context of files?
service dhcpd configtest
chcon
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
This chapter described tdbsm and smbpasswd back-end authentication.

17. What file is used to maintain custom parameters for the kernel during system boot?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
You must open TCP ports 20 and 21 for the FTP server to function properly.

18. What command can you use to create your own repositories?
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
run on any port you'd like (provided that port is available)
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
createrepo

19. What does the testparm command do?
support for TCP Wrappers
halts the system
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
setsebool -P nfs_export_all_rw=1

20. What command and options can you use to update the time?
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
The rndc utility provides a method for managing the DNS server remotely and securely.
serve both files and printers to users
Kickstart supports both basic and advanced partitioning (RAID/LVM).

21. What is the superblock used for?
chkconfig—list
have the same effect
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.

22. What is the default port that Squid runs on?
A user's home directory is created under the /home directory.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
By default - Squid runs on port 3128.
The virsh command is used to manage virtual guests.

23. What command can you use to validate the syntax of the Apache config file?
service httpd configtest
createrepo
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Sendmail

24. What client-side command can you use to test your FTP server connection?
The ping command can be used to verify connectivity to another host.
Public/private key authentication provides an additional layer of security because you need the correct key instead of just knowing someone's password. Passwords combined with public/private keys take the security one additional step.
The lftp command can be used on a client to test FTP server connections.
By defining a %post section - you can run scripts after a kickstart installation is complete.

25. What port does NFS use by default?
When the system starts up again - the cron service will run any jobs that were missed while the system was off. On Red Hat Enterprise Linux 5 - the anacron service handles this functionality.
generates errors under Red Hat Enterprise Linux 6
The NFS service uses TCP port 2049 by default.
The install.log.syslog file contains messages that are generated during the installation. If you run into trouble during the installation - this is a good place to start.

26. Can you name three utilities that can be used for network or DNS client troubleshooting?
useradd -c "Jr Admin" George
The three utilities are: route - ping - and nslookup.
The lftp command can be used on a client to test FTP server connections.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.

27. What command can you use to manage system services?
Public/private key authentication provides an additional layer of security because you need the correct key instead of just knowing someone's password. Passwords combined with public/private keys take the security one additional step.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
LUKS encryption
The service command is used to start - stop - and manage system services.

28. What is SSH used for?
The -t nfs option is used with the mount command to mount NFS resources.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
SSH is used for secure remote management of Linux systems.
Physical volumes - volume groups - and logical volumes.

29. What command can you use to monitor and troubleshoot network connections?
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
The /var/log/audit/audit.log file contains all policy violations.
The tcpdump command is used to monitor network connections on different interfaces.
You must open TCP ports 20 and 21 for the FTP server to function properly.

30. What is the last rule in the iptables file?

31. What is the /etc/hosts file used for?

32. There are four types of DNS servers. Name them.
This chapter described tdbsm and smbpasswd back-end authentication.
via the command line
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The four types of DNS servers are master - slave - caching-only - and forwarding.

33. What is a swap? Is it created as a partition or device file?
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
A swap is scratch space on your file system used as virtual memory. A swap can be created as a partition or a device file.
chcon

34. What is the point of using SELinux?
SELinux provides enhanced granular security for the Linux operating system.
SELinux Booleans provide restrictions to different aspects of a service.
service httpd configtest
SSH is used for secure remote management of Linux systems.

35. Explain the difference between soft and hard limits in quotas.

36. How would you install a group of packages all at a single time?
ifconfig
This command reboots virtual guest Client04.
This chapter described tdbsm and smbpasswd back-end authentication.
Use the yum groupinstall command to install multiple packages in a single group at once.

37. What command can be used to view the queue for at service jobs?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
browseable option
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
atq

38. What commands can you use to add a client machine to an LDAP server?
kickstart installations to work
You can use the authconfig-tui command or the authconfig command.
entering rescue mode and repairing the problem.
Kickstart supports both basic and advanced partitioning (RAID/LVM).

39. How can you list all services on the system to tell whether they will boot during startup?
chkconfig—list
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
Apache uses port 80 for HTTP and port 443 for HTTPS.
A user's home directory is created under the /home directory.

40. What command can you use to view system processes and their CPU usage?
Use the top command to view CPU and memory usage.
Use the ps command to view processes and their CPU usage.
support for TCP Wrappers
The service command is used to start - stop - and manage system services.

41. How would you go about creating a static route?
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
Use the route command with the add option to create a static route.
The install.log.syslog file contains messages that are generated during the installation. If you run into trouble during the installation - this is a good place to start.
Use the ps command to view processes and their CPU usage.

42. What command can you use to test connectivity to another host?
SSH is used for secure remote management of Linux systems.
The service command is used to start - stop - and manage system services.
The ping command can be used to verify connectivity to another host.
You can use the -q option to query an installed package. Combining grep and the -qa options - you can search among all installed packages on the system.

43. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
A large warning message appears indicating that the key doesn't match the host you are connecting to. You have to remove the key/host pair from the known_hosts file to proceed.
Sendmail
VNC is used to control a remote desktop session.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

44. What command and option can you use to enable a service to start on boot?
The dig - host - and ping commands can be used to test DNS server functionality.
amount of RAM
Network installations can be performed using the HTTP - FTP - and NFS protocols.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

45. What three protocols can you use to perform network installations?
The firewall rule is inserted into the fifth line of the iptables rules and opens up TCP port 80 (for the HTTP service) on the firewall to allow incoming connections.
When you exit the parted utility - all your changes are automatically written to disk. With the fdisk command - you need to manually write your changes to disk for them to take effect.
By default - Squid runs on port 3128.
Network installations can be performed using the HTTP - FTP - and NFS protocols.

46. Editing the /etc/xinetd.d/tftp file and enabling the service are the same as running the chkconfig tftp on command. Both of these actions...
mkfs.ext4
have the same effect
The DHCP server listens on port 67 by default.
By default - the rndc utility listens on port 953.

47. What is the benefit of using public/private key authentication?

48. What is the biggest benefit to using LVM over basic partitions?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
You have the flexibility to resize and add new volumes on the fly. With basic partitions - any time that you want to make a change - you need to destroy the partition and create it again.
The rndc utility provides a method for managing the DNS server remotely and securely.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

49. What is a gateway used for on a network?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
When the system enters into runlevel 2 - the rsyslog service has a priority of 12 when starting. Anything with a lower number (or the same number and lower first letter) starts before the rsyslog service.
A gateway is used as an entry and exit point for a subnet on a network. To contact hosts outside your subnet - you need to pass through a gateway.
Use the setgid flag to create the appropriate permissions (chmod 2770).

50. How do you run a command with elevated privileges?
The three utilities are: route - ping - and nslookup.
user's home directory in the /etc/skel directory
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.