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 the point of using SELinux?
SELinux provides enhanced granular security for the Linux operating system.
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 gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The user_list file can be used to limit which users have access to the FTP server.

2. What two commands are used for package management?
serve both files and printers to users
SELinux provides enhanced granular security for the Linux operating system.
The yum and rpm commands are used for package management.
Use the yum groupinstall command to install multiple packages in a single group at once.

3. What port on the firewall needs to be open for the TFTP server to work?
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.
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 /etc/fstab file.
The TFTP server uses UDP port 69.

4. Most boot issues can be resolved by...
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The ping command can be used to verify connectivity to another host.
entering rescue mode and repairing the problem.
chkconfig sshd off

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

6. What command is used to create an RPM package?
rpmbuild
The du and df commands are used to view available space on the system.
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.
getsebool -a | grep http

7. What command can you use to view mounted Samba shares?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
useradd -c "Jr Admin" George
The smbstatus command shows you currently mounted Samba resources.

8. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
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.
Enforcing during installation
The service command is used to start - stop - and manage system services.
Use the ps command to view processes and their CPU usage.

9. What command can you use to create a new SSL certificate?
cat /proc/mdstat
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
run on any port you'd like (provided that port is available)
serve both files and printers to users

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

11. 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.
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 user_list file can be used to limit which users have access to the FTP server.

12. What port does the rndc utility listen on by default?
By default - the rndc utility listens on port 953.
createrepo
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
The virsh command is used to manage virtual guests.

13. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
The dig - host - and ping commands can be used to test DNS server functionality.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
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.
Use the setgid flag to create the appropriate permissions (chmod 2770).

14. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
Use the top command to view CPU and memory usage.
Enforcing during installation
The virsh command is used to manage virtual guests.
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.

15. How would you go about creating a static route?
Use the route command with the add option to create a static route.
support for TCP Wrappers
A virtual host is a way of hosting multiple sites using a single IP address.
The lftp command can be used on a client to test FTP server connections.

16. What is the top command used for?
The dig - host - and ping commands can be used to test DNS server functionality.
The two main config files are master.cf and main.cf.
Use the top command to view CPU and memory usage.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

17. What is a virtual host?
A virtual host is a way of hosting multiple sites using a single IP address.
Enforcing during installation
The SMTP service runs on TCP port 110.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

18. What file needs to be edited so that the system will mount a file system at boot time?
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
The mount command lists all currently mounted file systems.
The /etc/fstab file.

19. What command-line program can you use to check your mail?
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.
Typing the mail or mutt command allows you to read mail from the command line.
ifconfig
The rdnc-confgen command generates an rndc.conf file for the rndc utility.

20. 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 lastlog and faillog commands are used to view user login-related events?
have the same effect
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George

21. The firewall service is...
The ping command can be used to verify connectivity to another host.
SELinux Booleans provide restrictions to different aspects of a service.
The /var/log/audit/audit.log file contains all policy violations.
enabled by default

22. FTP is one of three protocols ______________. The other two protocols are NFS and HTTP.
The user_list file can be used to limit which users have access to the FTP server.
setsebool -P nfs_export_all_rw=1
createrepo
used for kickstart and/or network installs

23. There are four types of DNS servers. Name them.
The anonymous_enable=YES option in the main config file allows anonymous uploads.
You can use the authconfig-tui command or the authconfig command.
The four types of DNS servers are master - slave - caching-only - and forwarding.
The nfsstat command can be used to view NFS statistics.

24. What command can you use to create your own repositories?
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
createrepo
service named configtest
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.

25. What three commands can you use to help verify that the DNS server is functioning properly?
The dig - host - and ping commands can be used to test DNS server functionality.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
choose which mode you'd like it to operate in
user's home directory in the /etc/skel directory

26. What command displays your current interfaces and IP address?
lvdisplay
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.
ifconfig
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.

27. What is a swap? Is it created as a partition or device file?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
DNS uses port 53.
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 swap is scratch space on your file system used as virtual memory. A swap can be created as a partition or a device file.

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

29. The package selection screen allows you to install any software you want during the installation process as long as...
createrepo
you have access to the correct packages or repositories.
chkconfig—list
support TCP Wrappers

30. What happens if a host changes its IP address and the keys don't match?

31. What command is used to create a user for Samba?
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The smbpasswd command is used to create Samba users.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

32. What command is used to show all services being controlled by the xinetd daemon?
getsebool
The dig - host - and ping commands can be used to test DNS server functionality.
chkconfig xinetd --list
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.

33. What are the three items that make up LVM?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
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.
Physical volumes - volume groups - and logical volumes.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.

34. What command can you use to create a file system?
The service command is used to start - stop - and manage system services.
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.
The dig - host - and ping commands can be used to test DNS server functionality.
mkfs.ext4

35. What command can you use to test connectivity to another host?
The ping command can be used to verify connectivity to another host.
DNS uses port 53.
A virtual host is a way of hosting multiple sites using a single IP address.
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.

36. What is a gateway used for on a network?
service sshd statuts
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
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.
The TFTP server uses UDP port 69.

37. Where are Yum repository config files located?
The vsftpd package is used to install an FTP server.
The three utilities are: route - ping - and nslookup.
DNS uses port 53.
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.

38. In Red Hat Enterprise Linux 6 - the default for SELinux is _______________ (which can be changed after the installation completes). For Red Hat Enterprise Linux 5 - you were able to choose what mode you wanted SELinux to start in.
You can use the authconfig-tui command or the authconfig command.
Enforcing during installation
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
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.

39. 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...

40. What does the testparm command do?
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
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.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
alternatives --config mta

41. What does the partprobe command do?
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
Use the yum groupinstall command to install multiple packages in a single group at once.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

42. What option would you use to query an installed package using the rpm command?
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.
The tcpdump command is used to monitor network connections on different interfaces.
service httpd configtest
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. What command can you use to validate the syntax of the Apache config file?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
The htpasswd command can be used to password-protect a web page.
you have access to the correct packages or repositories.
service httpd configtest

44. What are the two types of back-end authentication mechanisms discussed in this chapter?
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
Version 2 is the latest and most secure version of SSH.
This chapter described tdbsm and smbpasswd back-end authentication.
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.

45. What commands can you use to add a client machine to an LDAP server?
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.
You can use the authconfig-tui command or the authconfig command.
chkconfig—list
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

46. What are the three modes in which the rpm command can operate?
The virsh command is used to manage virtual guests.
The rpm command can operate in install - query - or verify modes.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The tcpdump command is used to monitor network connections on different interfaces.

47. What are the two config files for Postfix called?
Use the route command with the add option to create a static route.
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 /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The two main config files are master.cf and main.cf.

48. What is the difference between an A record and a PTR record?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
run on any port you'd like (provided that port is available)

49. What command (and options) can be used to create a user named George with the description "Jr Admin"?
chkconfig—list
useradd -c "Jr Admin" George
kickstart installations to work
Enforcing during installation

50. It is possible to run scripts before a kickstart installation. This is done by...
You can use the remove or erase options with yum to remove a package.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
defining a %pre section although it is rarely used