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 option can you change in the rsyslog config file to accept remote logs (acting as a centralized logging server)?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
SELinux provides enhanced granular security for the Linux operating system.
cat /proc/mdstat
The -t nfs option is used with the mount command to mount NFS resources.

2. The package selection screen allows you to install any software you want during the installation process as long as...
enabled by default
cat /proc/mdstat
you have access to the correct packages or repositories.
generates errors under Red Hat Enterprise Linux 6

3. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
The three utilities are: route - ping - and nslookup.
The du and df commands are used to view available space on the system.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
generates errors under Red Hat Enterprise Linux 6

4. There are four types of DNS servers. Name them.
The service command is used to start - stop - and manage system services.
entering rescue mode and repairing the problem.
The four types of DNS servers are master - slave - caching-only - and forwarding.
The two main config files are master.cf and main.cf.

5. 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...

6. What options with the yum command would you use to remove a package?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
You can use the remove or erase options with yum to remove a package.
This command reboots virtual guest Client04.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

7. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
rpcbind service
support for TCP Wrappers
run on any port you'd like (provided that port is available)
choose which mode you'd like it to operate in

8. How would you install a group of packages all at a single time?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
Sendmail
Use the yum groupinstall command to install multiple packages in a single group at once.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.

9. Does a DHCP server allow reserved IP addresses - If so - how?
The TFTP server uses UDP port 69.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
support TCP Wrappers

10. What happens if you call the command from question 3 with the -c option after it has already been run?
You add your action to the end of the /home/user01/.bashrc file.
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.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

11. What command-line program can you use to check your mail?
support TCP Wrappers
Typing the mail or mutt command allows you to read mail from the command line.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
The du and df commands are used to view available space on the system.

12. How would you view all Boolean options for the HTTP service?
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.
getsebool -a | grep http
serve both files and printers to users
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.

13. To create a RAID or LVM partition using kickstart
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
Use the setgid flag to create the appropriate permissions (chmod 2770).

14. What is the difference between an ext2 and ext3 file system?

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...
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
The anonymous_enable=YES option in the main config file allows anonymous uploads.
have the same effect
service named configtest

16. What option would you use to query an installed package using the rpm command?
The rndc utility provides a method for managing the DNS server remotely and securely.
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 that stores usernames and their encrypted passwords is erased and replaced with a new file.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.

17. 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.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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.
The nfsstat command can be used to view NFS statistics.

18. Can you put your /boot partition on a RAID 5 array?
ifconfig
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.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
The rndc utility provides a method for managing the DNS server remotely and securely.

19. What command can you use to query Boolean values?
getsebool
The dig - host - and ping commands can be used to test DNS server functionality.
service named configtest
kickstart installations to work

20. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
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 superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The ping command can be used to verify connectivity to another host.
A virtual host is a way of hosting multiple sites using a single IP address.

21. What is the format of the /etc/shadow file?
The three utilities are: route - ping - and nslookup.
support for TCP Wrappers
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
SSH is used for secure remote management of Linux systems.

22. 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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
The du and df commands are used to view available space on the system.

23. What are the three modes in which the rpm command can operate?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
SELinux Booleans provide restrictions to different aspects of a service.
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.
The rpm command can operate in install - query - or verify modes.

24. The exportfs command is used to...
Version 2 is the latest and most secure version of SSH.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
export one or all resources
getsebool -a | grep http

25. What command (and options) can be used to create a user named George with the description "Jr Admin"?
The tcpdump command is used to monitor network connections on different interfaces.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
useradd -c "Jr Admin" George
chkconfig—list

26. What three components are needed to fully automate a kickstart installation?
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.
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.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.

27. What does it mean if you ping a host and you receive the response Destination Unreachable?
have the same effect
getfacl
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

28. What command can you use to view the current ACL on a file?
Sendmail
getfacl
schedule one-time-only jobs
ifconfig

29. What is the default port that Squid runs on?
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 lftp command can be used on a client to test FTP server connections.
By default - Squid runs on port 3128.
Enforcing during installation

30. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
service sshd statuts
chkconfig—list
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
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.

31. What is the rndc utility used for?
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
amount of RAM
The rndc utility provides a method for managing the DNS server remotely and securely.

32. What command is used to create a user for Samba?
amount of RAM
The smbpasswd command is used to create Samba users.
load balancing and redundancy benefits
browseable option

33. What is a gateway used for on a network?
amount of RAM
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.
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.
browseable option

34. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
user's home directory in the /etc/skel directory
Use the yum groupinstall command to install multiple packages in a single group at once.
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

35. What port on the firewall needs to be open for the TFTP server to work?
The TFTP server uses UDP port 69.
This command reboots virtual guest Client04.
You must open TCP ports 20 and 21 for the FTP server to function properly.
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.

36. What command would you use to create a group - to add the user George to the group?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
run on any port you'd like (provided that port is available)
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
getfacl

37. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
getsebool
atq

38. What directory is used to represent the virtual file system created by the kernel?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The nfsstat command can be used to view NFS statistics.
Enforcing during installation
Kickstart supports both basic and advanced partitioning (RAID/LVM).

39. What command can you use to monitor and troubleshoot network connections?
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.
load balancing and redundancy benefits
The tcpdump command is used to monitor network connections on different interfaces.
service httpd configtest

40. The ____________ is available for each share.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The vsftpd package is used to install an FTP server.
browseable option
chkconfig sshd off

41. What port does the rndc utility listen on by default?
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.
useradd -c "Jr Admin" George
Use the top command to view CPU and memory usage.
By default - the rndc utility listens on port 953.

42. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
SELinux Booleans provide restrictions to different aspects of a service.
Enforcing during installation
Use the resize2fs command to grow a file system.
LUKS encryption

43. What is the name of the package used to install an FTP?
The /etc/fstab file.
This command reboots virtual guest Client04.
LUKS encryption
The vsftpd package is used to install an FTP server.

44. What is the benefit to using centralized authentication?

45. What command can you use to view system processes and their CPU usage?
Use the ps command to view processes and their CPU usage.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
SSH is used for secure remote management of Linux systems.
mkfs.ext4

46. What option at the GRUB boot menu can you use to append something to a kernel?
setsebool -P nfs_export_all_rw=1
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
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.
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.

47. What are the two types of back-end authentication mechanisms discussed in this chapter?
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
defining a %pre section although it is rarely used
Using the chcon command - you can change the context of a file to work with Apache.
This chapter described tdbsm and smbpasswd back-end authentication.

48. How can you check the currently mounted file systems?
run on any port you'd like (provided that port is available)
getfacl
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
The mount command lists all currently mounted file systems.

49. What does virsh reboot Client04 do?
choose which mode you'd like it to operate in
The rpm command can operate in install - query - or verify modes.
This command reboots virtual guest Client04.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

50. What command can you use to change the context of files?
chcon
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
schedule one-time-only jobs
A virtual host is a way of hosting multiple sites using a single IP address.