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 port must be opened on the firewall for DNS?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
DNS uses port 53.
The yum and rpm commands are used for package management.
The /etc/fstab file.

2. What happens if you call the command from question 3 with the -c option after it has already been run?
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.
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.
generates errors under Red Hat Enterprise Linux 6

3. What is NAT - How is it used?
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers 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.
browseable option
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.

4. What commands can you use to add a client machine to an LDAP server?
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.
You can use the authconfig-tui command or the authconfig command.
getsebool
The DHCP server listens on port 67 by default.

5. Before you work with quotas - what do you need to do to the file system?
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
For Apache to run a secure site - the mod_ssl package is required to be installed.
run on any port you'd like (provided that port is available)
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

6. Most boot issues can be resolved by...
The /etc/fstab file.
Use the route command with the add option to create a static route.
The yum and rpm commands are used for package management.
entering rescue mode and repairing the problem.

7. What command can you use to view the current ACL on a file?
Use the resize2fs command to grow a file system.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
getfacl

8. What command do you use to report information on quota usage?
Use the setgid flag to create the appropriate permissions (chmod 2770).
chkconfig—list
repquota
halts the system

9. 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.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
The dig - host - and ping commands can be used to test DNS server functionality.
The virsh command is used to manage virtual guests.

10. The firewall service is...
The lftp command can be used on a client to test FTP server connections.
LUKS encryption
enabled by default
You must open TCP ports 20 and 21 for the FTP server to function properly.

11. You must dictate the ____________ you want allocated to your virtual machine when you create it.
You must open TCP ports 20 and 21 for the FTP server to function properly.
service named configtest
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.

12. What two commands are used for package management?
serve both files and printers to users
have the same effect
user's home directory in the /etc/skel directory
The yum and rpm commands are used for package management.

13. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
getsebool -a | grep http
You add your action to the end of the /home/user01/.bashrc file.
chkconfig—list
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.

14. What two ports should be opened on the firewall for the FTP server to function properly?
Use the resize2fs command to grow a file system.
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.
Use the ps command to view processes and their CPU usage.
You must open TCP ports 20 and 21 for the FTP server to function properly.

15. What is the /var/lib/nfs/etab file used for?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The user_list file can be used to limit which users have access to the FTP server.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

16. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
A soft limit acts like an alarm - signaling you when you are reaching your limit. If you don't specify a grace period - the soft limit is the max. A hard limit is required only when a grace period exists. It is the max limit you can hit before your g
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.
This command reboots virtual guest Client04.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

17. What command can you use to query Boolean values?
getsebool
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
amount of RAM
By default - Squid runs on port 3128.

18. What is PAM used for?
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.
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 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.
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.

19. What critical step must you take after updating the kernel to a newer version?
generates errors under Red Hat Enterprise Linux 6
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 lftp command can be used on a client to test FTP server connections.
atq

20. SSH does...
chkconfig—list
used for kickstart and/or network installs
The rpm command can operate in install - query - or verify modes.
support TCP Wrappers

21. What command can be used to easily list all the options in the FTP main config file?
Using the chcon command - you can change the context of a file to work with Apache.
export one or all resources
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
support for TCP Wrappers

22. What command can you use to view mounted Samba shares?
The lastlog and faillog commands are used to view user login-related events?
The SMTP service runs on TCP port 110.
The lftp command can be used on a client to test FTP server connections.
The smbstatus command shows you currently mounted Samba resources.

23. What command is used to create a user for Samba?
ifconfig
export one or all resources
The smbpasswd command is used to create Samba users.
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.

24. What directory is used to represent the virtual file system created by 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.
Enforcing during installation
The lastlog and faillog commands are used to view user login-related events?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

25. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
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.
Use the top command to view CPU and memory usage.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
By default - Squid runs on port 3128.

26. What is SSH used for?
The vsftpd package is used to install an FTP server.
SSH is used for secure remote management of Linux systems.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
rpmbuild

27. What command can be used to view the queue for at service jobs?
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.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
atq
have the same effect

28. 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.
The tcpdump command is used to monitor network connections on different interfaces.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The -t nfs option is used with the mount command to mount NFS resources.

29. What is the main config file for the DHCP service?
The two main config files are master.cf and main.cf.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
By default - Squid runs on port 3128.

30. To create a RAID or LVM partition using kickstart
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The three utilities are: route - ping - and nslookup.
rpcbind service
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

31. How can you change the security context of a directory to work with Apache?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
Using the chcon command - you can change the context of a file to work with Apache.
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

32. What option needs to be used with the mount command to mount an NFS resource?
The -t nfs option is used with the mount command to mount NFS resources.
kickstart installations to work
By defining a %post section - you can run scripts after a kickstart installation is complete.
used for kickstart and/or network installs

33. What options with the yum command would you use to remove a package?
defining a %pre section although it is rarely used
export one or all resources
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
You can use the remove or erase options with yum to remove a package.

34. What command can you use to query information from the kernel about RAID arrays?
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.
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.
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.
cat /proc/mdstat

35. A service needs to have _______________ to be able to use it.
The htpasswd command can be used to password-protect a web page.
cat /proc/mdstat
The lastlog and faillog commands are used to view user login-related events?
support for TCP Wrappers

36. Samba servers can...
kickstart installations to work
serve both files and printers to users
choose which mode you'd like it to operate in
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

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

38. What command and option do you use to view the description of Boolean values?
chkconfig—list
semanage boolean -l
kickstart installations to work
cat /proc/mdstat

39. Before you work with ACLs - what do you need to do to the file system?
SELinux provides enhanced granular security for the Linux operating system.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
You can use the authconfig-tui command or the authconfig command.
load balancing and redundancy benefits

40. Which file shows you all the client IP addresses?
The mount command lists all currently mounted file systems.
The dig - host - and ping commands can be used to test DNS server functionality.
The user_list file can be used to limit which users have access to the FTP server.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

41. What command can you use to test the config files before starting the DNS service?
A user's home directory is created under the /home directory.
service named configtest
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
getfacl

42. To grow a file system
kickstart installations to work
entering rescue mode and repairing the problem.
Use the resize2fs command to grow a file system.
The /var/log/audit/audit.log file contains all policy violations.

43. What option is used to allow anonymous uploads to the FTP server?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
The print option is used with both the fdisk and parted commands to display the current partition tables.
The nfsstat command can be used to view NFS statistics.
kickstart installations to work

44. What is VNC?
service dhcpd configtest
Apache uses port 80 for HTTP and port 443 for HTTPS.
VNC is used to control a remote desktop session.
The anonymous_enable=YES option in the main config file allows anonymous uploads.

45. What port does the DHCP server listen on by default?
The DHCP server listens on port 67 by default.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
This chapter described tdbsm and smbpasswd back-end authentication.
via the command line

46. What is the xinetd service used for?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The ping command can be used to verify connectivity to another host.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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.

47. Can you put your /boot partition on a RAID 5 array?
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
service httpd configtest
A user's home directory is created under the /home directory.

48. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
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
Use the setgid flag to create the appropriate permissions (chmod 2770).
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 DHCP server listens on port 67 by default.

49. How would you go about creating a static route?
The TFTP server uses UDP port 69.
entering rescue mode and repairing the problem.
Use the route command with the add option to create a static route.
setsebool -P nfs_export_all_rw=1

50. What are the three modes in which the rpm command can operate?
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 lastlog and faillog commands are used to view user login-related events?
used for kickstart and/or network installs