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. What is PAM used for?
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 partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
Use the yum groupinstall command to install multiple packages in a single group at once.
via the command line

2. What is a swap? Is it created as a partition or device file?
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
service httpd configtest
The nfsstat command can be used to view NFS statistics.
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.

3. What is the main config file for the DHCP service?
choose which mode you'd like it to operate in
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
getfacl
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

4. What is the difference between an A record and a PTR record?
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
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.
generates errors under Red Hat Enterprise Linux 6

5. What are the three modes in which the rpm command can operate?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The rpm command can operate in install - query - or verify modes.
SELinux Booleans provide restrictions to different aspects of a service.

6. What command can you use to check the config file of the DHCP server?
The service command is used to start - stop - and manage system services.
The smbstatus command shows you currently mounted Samba resources.
By default - the rndc utility listens on port 953.
service dhcpd configtest

7. What does the testparm command do?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The lastlog and faillog commands are used to view user login-related events?
The SMTP service runs on TCP port 110.

8. What command can be used to easily list all the options in the FTP main config file?
Sendmail
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
The user_list file can be used to limit which users have access to the FTP server.

9. What is the name of the package that allows you to install VNC?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The lftp command can be used on a client to test FTP server connections.
The smbstatus command shows you currently mounted Samba resources.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

10. What command can you use to test connectivity to another host?
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.
The ping command can be used to verify connectivity to another host.
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 using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

11. What is the biggest benefit to using LVM over basic partitions?
export one or all resources
rpcbind service
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.
chcon

12. What three commands can you use to help verify that the DNS server is functioning properly?
browseable option
The dig - host - and ping commands can be used to test DNS server functionality.
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.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

13. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
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.
Use the route command with the add option to create a static route.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
If you shrink a volume group or logical volume - there is a chance you could lose data depending on how much you shrink the volume.

14. What does the partprobe command do?
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
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
SELinux Booleans provide restrictions to different aspects of a service.

15. What port on the firewall needs to be open for the TFTP server to work?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The TFTP server uses UDP port 69.
The service command is used to start - stop - and manage system services.
The -t nfs option is used with the mount command to mount NFS resources.

16. What command can you use to create your own repositories?
createrepo
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.
The du and df commands are used to view available space on the system.
The service command is used to start - stop - and manage system services.

17. A slave DNS server provides...
The -t nfs option is used with the mount command to mount NFS resources.
load balancing and redundancy benefits
support for TCP Wrappers
By default - Squid runs on port 3128.

18. The firewall service is...
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
enabled by default
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 -t nfs option is used with the mount command to mount NFS resources.

19. SSH does...
schedule one-time-only jobs
SSH is used for secure remote management of Linux systems.
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.
support TCP Wrappers

20. What command and option can you use to enable a service to start on boot?
rpmbuild
The TFTP server uses UDP port 69.
Version 2 is the latest and most secure version of SSH.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

21. Should you allow remote root access - Why or why not?

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

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23. What is the xinetd service used for?
LUKS encryption
The yum and rpm commands are used for package management.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

24. How can you list all services on the system to tell whether they will boot during startup?
SELinux Booleans provide restrictions to different aspects of a service.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
Typing the mail or mutt command allows you to read mail from the command line.
chkconfig—list

25. What two ports should be opened on the firewall for the FTP server to function properly?
By default - Squid runs on port 3128.
You must open TCP ports 20 and 21 for the FTP server to function properly.
Enforcing during installation
mkfs.ext4

26. The ____________ is available for each share.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
browseable option
You add your action to the end of the /home/user01/.bashrc file.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.

27. Runlevel 0 ___________. Runlevel 6 reboots the system.
The SMTP service runs on TCP port 110.
halts the system
The tcpdump command is used to monitor network connections on different interfaces.
Use the resize2fs command to grow a file system.

28. What command is used to show all services being controlled by the xinetd daemon?
getfacl
amount of RAM
getsebool -a | grep http
chkconfig xinetd --list

29. What does it mean if you ping a host and you receive the response Destination Unreachable?
You must open TCP ports 20 and 21 for the FTP server to function properly.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
load balancing and redundancy benefits

30. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
SELinux Booleans provide restrictions to different aspects of a service.
user's home directory in the /etc/skel directory
Use the setgid flag to create the appropriate permissions (chmod 2770).
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

31. What happens if you call the command from question 3 with the -c option after it has already been run?
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.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
getsebool -a | grep http

32. What command would you use to create a group - to add the user George to the group?
The lftp command can be used on a client to test FTP server connections.
setsebool -P nfs_export_all_rw=1
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.

33. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
enabled by default
You add your action to the end of the /home/user01/.bashrc file.
user's home directory in the /etc/skel directory
LUKS encryption

34. FTP is one of three protocols ______________. The other two protocols are NFS and HTTP.
used for kickstart and/or network installs
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.
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 /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

35. What is the /etc/vsftpd/user_list file used for?
The user_list file can be used to limit which users have access to the FTP server.
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.
Yum repository config files (.repo files) are located in the /etc/yum.repos.d directory. You can also make direct entries into the main /etc/yum.conf file.
Network installations can be performed using the HTTP - FTP - and NFS protocols.

36. What are the two config files for Postfix called?
support TCP Wrappers
ifconfig
The two main config files are master.cf and main.cf.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

37. Can you put your /boot partition on a RAID 5 array?
SSH is used for secure remote management of Linux systems.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
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.
service named configtest

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

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39. What file needs to be edited so that the system will mount a file system at boot time?
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 /etc/fstab file.
Using the chcon command - you can change the context of a file to work with Apache.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

40. What command can you use to view system processes and their CPU usage?
SSH is used for secure remote management of Linux systems.
service httpd configtest
Use the ps command to view processes and their CPU usage.
LUKS encryption

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

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42. What command can you use to manage system services?
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
Sendmail
The service command is used to start - stop - and manage system services.
service named configtest

43. What are the two types of back-end authentication mechanisms discussed in this chapter?
rpcbind service
used for kickstart and/or network installs
This chapter described tdbsm and smbpasswd back-end authentication.
Yum repository config files (.repo files) are located in the /etc/yum.repos.d directory. You can also make direct entries into the main /etc/yum.conf file.

44. How can you check the currently mounted file systems?
The mount command lists all currently mounted file systems.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
getsebool
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

45. What is the superblock used for?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
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 /var/lib/nfs/etab file is used to keep track of currently exported resources.
VNC is used to control a remote desktop session.

46. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
Enforcing during installation
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.
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.
useradd -c "Jr Admin" George

47. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
Sendmail
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

48. What is SSH used for?
schedule one-time-only jobs
SSH is used for secure remote management of Linux systems.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
VNC is used to control a remote desktop session.

49. What is NAT - How is it used?
You can use the remove or erase options with yum to remove a package.
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.
The DHCP server listens on port 67 by default.
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.

50. What is VNC?
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.
VNC is used to control a remote desktop session.
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
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.