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. A service needs to have _______________ to be able to use it.
The SSH service is almost always installed by default in Red Hat. It uses TCP port 22 - and this port is open on the default firewall rules.
The tcpdump command is used to monitor network connections on different interfaces.
The TFTP server uses UDP port 69.
support for TCP Wrappers

2. What does the testparm command do?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
support for TCP Wrappers
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.
semanage boolean -l

3. What is the virsh command used for?
chkconfig xinetd --list
Use the yum groupinstall command to install multiple packages in a single group at once.
The virsh command is used to manage virtual guests.
run on any port you'd like (provided that port is available)

4. What command can you use to change the context of files?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
Use the top command to view CPU and memory usage.
The two main config files are master.cf and main.cf.
chcon

5. What are the three different types of RAID described in this chapter?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
choose which mode you'd like it to operate in
DNS uses port 53.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

6. A PXE server eases the automation process but isn't required for...
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The user_list file can be used to limit which users have access to the FTP server.
kickstart installations to work
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

7. How can you display all virtual guests after they're connected to a hypervisor?
Use the resize2fs command to grow a file system.
support TCP Wrappers
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

8. What happens if you call the command from question 3 with the -c option after it has already been run?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
You should never allow remote root access. Should your root account become compromised and you use the same password - someone could gain access to all your systems. You also don't want the most powerful user of your system (with no accountability) l
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

9. What command and option do you use to view the description of Boolean values?
This chapter described tdbsm and smbpasswd back-end authentication.
SELinux Booleans provide restrictions to different aspects of a service.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
semanage boolean -l

10. What command can you use to check the config file of the DHCP server?
The lftp command can be used on a client to test FTP server 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.
service dhcpd configtest
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

11. Can you name the two commands that can be used to view the free space on the system?
A virtual host is a way of hosting multiple sites using a single IP address.
The vsftpd package is used to install an FTP server.
The du and df commands are used to view available space on the system.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

12. SSH does...
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.
service named configtest
support TCP Wrappers
support for TCP Wrappers

13. How would you disable SELinux protection for NFS - allowing shares to be read/write?
This is actually a trick question because the answer could go either way. In this chapter - we discussed only software RAID setups - in which case the answer is no. If - however - you were using a hardware RAID 5 - the answer would be yes.
Typing the mail or mutt command allows you to read mail from the command line.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
setsebool -P nfs_export_all_rw=1

14. How can virtual hosts be used?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
The yum and rpm commands are used for package management.
If you are a hosting company or want to run multiple websites/applications from a single IP address - you can use virtual hosts to accomplish this.

15. 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...
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
The du and df commands are used to view available space on the system.
This command reboots virtual guest Client04.
have the same effect

16. What file is used to maintain custom parameters for the kernel during system boot?
The DHCP server listens on port 67 by default.
chkconfig—list
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.

17. What critical step must you take after updating the kernel to a newer version?
The SSH service is almost always installed by default in Red Hat. It uses TCP port 22 - and this port is open on the default firewall rules.
chkconfig—list
You must ensure that the /boot/grub/grub.conf file has the new entry for your newly updated kernel to be able to boot into it.
SSH is used for secure remote management of Linux systems.

18. What directory is used to represent the virtual file system created by the kernel?
By defining a %post section - you can run scripts after a kickstart installation is complete.
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.
export one or all resources
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

19. Before you work with quotas - what do you need to do to the file system?
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
The smbpasswd command is used to create Samba users.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
You must ensure that the /boot/grub/grub.conf file has the new entry for your newly updated kernel to be able to boot into it.

20. What command can you use to test the config files before starting the DNS service?
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
service named configtest
The virsh command is used to manage virtual guests.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

21. What command do you use to change the permissions on a file or directory - To change ownership?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
rpmbuild
The chmod command is used to change the permissions of files and directories. The chown command is used to change the ownership of files and directories.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George

22. What file needs to be edited so that the system will mount a file system at boot time?
The rndc utility provides a method for managing the DNS server remotely and securely.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The /etc/fstab file.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

23. How can you verify the status of the SSH service after the system has booted?
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.
generates errors under Red Hat Enterprise Linux 6
The mount command lists all currently mounted file systems.
service sshd statuts

24. Red Hat Enterprise Linux 6 is the only version that officially supports _______
The DHCP server listens on port 67 by default.
LUKS encryption
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
enabled by default

25. What command can you use to create a new SSL certificate?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
Use the route command with the add option to create a static route.
You add your action to the end of the /home/user01/.bashrc file.
The rpm command can operate in install - query - or verify modes.

26. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
The TFTP server uses UDP port 69.
A user's home directory is created under the /home directory.
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.
chkconfig sshd off

27. Does a DHCP server allow reserved IP addresses - If so - how?
The htpasswd command can be used to password-protect a web page.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

28. What are the two types of back-end authentication mechanisms discussed in this chapter?
used for kickstart and/or network installs
halts the system
service sshd statuts
This chapter described tdbsm and smbpasswd back-end authentication.

29. What is the biggest benefit to using LVM over basic partitions?
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.
Use the top command to view CPU and memory usage.
The yum and rpm commands are used for package management.
setsebool -P nfs_export_all_rw=1

30. What command can you use to view system processes and their CPU usage?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
A user's home directory is created under the /home directory.
Use the ps command to view processes and their CPU usage.
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.

31. Samba servers can...
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
serve both files and printers to users
DNS uses port 53.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

32. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
chkconfig—list
Use the yum groupinstall command to install multiple packages in a single group at once.
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.
setsebool -P nfs_export_all_rw=1

33. What command can you use to query Boolean values?
Physical volumes - volume groups - and logical volumes.
The rpm command can operate in install - query - or verify modes.
getsebool
You can use the remove or erase options with yum to remove a package.

34. What command (and options) can be used to create a user named George with the description "Jr Admin"?
DNS uses port 53.
chcon
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
useradd -c "Jr Admin" George

35. Do you need to write changes to the disk when using the parted command? What about fdisk?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
service httpd configtest
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.

36. What command disables the SSH service from running when the system boots?
chkconfig sshd off
Use the ps command to view processes and their CPU usage.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The chmod command is used to change the permissions of files and directories. The chown command is used to change the ownership of files and directories.

37. How would you install a group of packages all at a single time?
entering rescue mode and repairing the problem.
By default - Squid runs on port 3128.
Use the yum groupinstall command to install multiple packages in a single group at once.
You can use the authconfig-tui command or the authconfig command.

38. What port does the rndc utility listen on by default?
VNC is used to control a remote desktop session.
The smbstatus command shows you currently mounted Samba resources.
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.
By default - the rndc utility listens on port 953.

39. What is the main config file for the DHCP service?
ifconfig
atq
You must open TCP ports 20 and 21 for the FTP server to function properly.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

40. For Red Hat Enterprise Linux 6 - SELinux comes set up in enforcing mode. When installing Red Hat Enterprise Linux 5 - you have the option to...

41. What is the point of using SELinux?
The SSH service is almost always installed by default in Red Hat. It uses TCP port 22 - and this port is open on the default firewall rules.
SELinux provides enhanced granular security for the Linux operating system.
choose which mode you'd like it to operate in
mkfs.ext4

42. It is possible to run scripts before a kickstart installation. This is done by...
defining a %pre section although it is rarely used
You must ensure that the /boot/grub/grub.conf file has the new entry for your newly updated kernel to be able to boot into it.
You can use the authconfig-tui command or the authconfig command.
The /var/log/audit/audit.log file contains all policy violations.

43. There are four types of DNS servers. Name them.
chkconfig sshd off
useradd -c "Jr Admin" George
used for kickstart and/or network installs
The four types of DNS servers are master - slave - caching-only - and forwarding.

44. What command can you use to monitor and troubleshoot network connections?
The tcpdump command is used to monitor network connections on different interfaces.
The print option is used with both the fdisk and parted commands to display the current partition tables.
DNS uses port 53.
setsebool -P nfs_export_all_rw=1

45. What command do you use to report information on quota usage?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
repquota
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.
useradd -c "Jr Admin" George

46. What port does the Apache web server run on - What about HTTPS?
alternatives --config mta
You can use the remove or erase options with yum to remove a package.
Apache uses port 80 for HTTP and port 443 for HTTPS.
chkconfig xinetd --list

47. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
A virtual host is a way of hosting multiple sites using a single IP address.
used for kickstart and/or network installs
generates errors under Red Hat Enterprise Linux 6
Use the yum groupinstall command to install multiple packages in a single group at once.

48. What is the difference between an A record and a PTR record?
service dhcpd configtest
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

49. What command can you use to create your own repositories?
You can use the authconfig-tui command or the authconfig command.
createrepo
Sendmail
The dig - host - and ping commands can be used to test DNS server functionality.

50. What port on the firewall needs to be open for the TFTP server to work?
Enforcing during installation
PAM is used as a modular way to leverage security. In this chapter - the main function we discussed was for managing password policies and complexity.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The TFTP server uses UDP port 69.