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 three commands can you use to help verify that the DNS server is functioning properly?
Use the ps command to view processes and their CPU usage.
Physical volumes - volume groups - and logical volumes.
The dig - host - and ping commands can be used to test DNS server functionality.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.

2. The package selection screen allows you to install any software you want during the installation process as long as...
you have access to the correct packages or repositories.
chkconfig—list
service sshd statuts
rpmbuild

3. What command can you use to view the current ACL on a file?
The TFTP server uses UDP port 69.
getfacl
export one or all 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.

4. You must dictate the ____________ you want allocated to your virtual machine when you create it.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
amount of RAM
The TFTP server uses UDP port 69.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

5. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
The yum and rpm commands are used for package management.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
By default - Squid runs on port 3128.
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.

6. What is the point of using SELinux?
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
By defining a %post section - you can run scripts after a kickstart installation is complete.
SELinux provides enhanced granular security for the Linux operating system.
The smbpasswd command is used to create Samba users.

7. How can you change the security context of a directory to work with Apache?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
By defining a %post section - you can run scripts after a kickstart installation is complete.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
Using the chcon command - you can change the context of a file to work with Apache.

8. What option is used with both the fdisk and parted commands to display the current partition tables?
The print option is used with both the fdisk and parted commands to display the current partition tables.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Use the setgid flag to create the appropriate permissions (chmod 2770).
lvdisplay

9. What option needs to be used with the mount command to mount an NFS resource?
serve both files and printers to users
The -t nfs option is used with the mount command to mount NFS resources.
used for kickstart and/or network installs
semanage boolean -l

10. What file needs to be edited so that the system will mount a file system at boot time?
LUKS encryption
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/fstab file.
Physical volumes - volume groups - and logical volumes.

11. Can you name three utilities that can be used for network or DNS client troubleshooting?
run on any port you'd like (provided that port is available)
The three utilities are: route - ping - and nslookup.
The TFTP server uses UDP port 69.
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 command can you use to view mounted Samba shares?
The smbstatus command shows you currently mounted Samba resources.
The NFS service uses TCP port 2049 by default.
Use the ps command to view processes and their CPU usage.
The lastlog and faillog commands are used to view user login-related events?

13. What command and options can you use to update the time?
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 dig - host - and ping commands can be used to test DNS server functionality.
export one or all resources
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

14. Explain the difference between soft and hard limits in quotas.

15. Which file shows you all the client IP addresses?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
choose which mode you'd like it to operate in
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.

16. Runlevel 0 ___________. Runlevel 6 reboots the system.
generates errors under Red Hat Enterprise Linux 6
This chapter described tdbsm and smbpasswd back-end authentication.
halts the system
The rndc utility provides a method for managing the DNS server remotely and securely.

17. What is a swap? Is it created as a partition or device file?
The /etc/fstab file.
schedule one-time-only 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.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

18. What command can you use to test connectivity to another host?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
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.
The ping command can be used to verify connectivity to another host.

19. What happens if you call the command from question 3 with the -c option after it has already been run?
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.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

20. What file is used to maintain custom parameters for the kernel during system boot?
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
You add your action to the end of the /home/user01/.bashrc file.
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.

21. What is the xinetd service used for?
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.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

22. What two commands are used for package management?
SELinux Booleans provide restrictions to different aspects of a service.
choose which mode you'd like it to operate in
The yum and rpm commands are used for package management.
The smbstatus command shows you currently mounted Samba resources.

23. What command (and options) can be used to create a user named George with the description "Jr Admin"?
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
useradd -c "Jr Admin" George
The /etc/fstab file.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

24. How can virtual hosts be used?
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.
Enforcing during installation
atq
Typing the mail or mutt command allows you to read mail from the command line.

25. What is NAT - How is it used?
The rpm command can operate in install - query - or verify modes.
The yum and rpm commands are used for package management.
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 ping command can be used to verify connectivity to another host.

26. Can you put your /boot partition on a RAID 5 array?
The virsh command is used to manage virtual guests.
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 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.
The mount command lists all currently mounted file systems.

27. What port does the SMTP service run on?
used for kickstart and/or network installs
The SMTP service runs on TCP port 110.
cat /proc/mdstat
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

28. What option at the GRUB boot menu can you use to append something to a kernel?
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.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The DHCP server listens on port 67 by default.

29. Place all files you want added to a _______________ during creation.

30. What command can you use to validate the syntax of the Apache config file?
service httpd configtest
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
SELinux provides enhanced granular security for the Linux operating system.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

31. What does it mean if you ping a host and you receive the response Destination Unreachable?
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
rpmbuild
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
You can use the remove or erase options with yum to remove a package.

32. To grow a file system
You add your action to the end of the /home/user01/.bashrc file.
Use the resize2fs command to grow a file system.
Enforcing during installation
The /etc/fstab file.

33. How can you verify the status of the SSH service after the system has booted?
chkconfig sshd off
The smbpasswd command is used to create Samba users.
service sshd statuts
Apache uses port 80 for HTTP and port 443 for HTTPS.

34. Before you work with ACLs - what do you need to do to the file system?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
amount of RAM
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

35. What is the default port that Squid runs on?
By default - Squid runs on port 3128.
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.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The two main config files are master.cf and main.cf.

36. 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 smbstatus command shows you currently mounted Samba resources.
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 three utilities are: route - ping - and nslookup.

37. 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.
getsebool -a | grep http
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
schedule one-time-only jobs

38. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
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.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
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 lftp command can be used on a client to test FTP server connections.

39. What command can you use to manage system services?
The service command is used to start - stop - and manage system services.
The yum and rpm commands are used for package management.
The vsftpd package is used to install an FTP server.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

40. What is the top command used for?
serve both files and printers to users
A user's home directory is created under the /home directory.
Use the top command to view CPU and memory usage.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.

41. What command can be used to easily list all the options in the FTP main config file?
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
run on any port you'd like (provided that port is available)
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

42. How would you install a group of packages all at a single time?
generates errors under Red Hat Enterprise Linux 6
choose which mode you'd like it to operate in
Use the yum groupinstall command to install multiple packages in a single group at once.
The rpm command can operate in install - query - or verify modes.

43. How would you disable SELinux protection for NFS - allowing shares to be read/write?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
setsebool -P nfs_export_all_rw=1
The two main config files are master.cf and main.cf.
generates errors under Red Hat Enterprise Linux 6

44. What is VNC?
Use the top command to view CPU and memory usage.
Use the setgid flag to create the appropriate permissions (chmod 2770).
DNS uses port 53.
VNC is used to control a remote desktop session.

45. How would you view all Boolean options for the HTTP service?
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.
getsebool -a | grep http
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.

46. How would you go about creating a static route?
Sendmail
Use the route command with the add option to create a static route.
have the same effect
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

47. What command can you use to check the config file of the DHCP server?
The four types of DNS servers are master - slave - caching-only - and forwarding.
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.
A virtual host is a way of hosting multiple sites using a single IP address.
service dhcpd configtest

48. What happens to jobs that are scheduled to run while the system is off?
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.
By default - Squid runs on port 3128.
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.

49. A service needs to have _______________ to be able to use it.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
getfacl
support for TCP Wrappers
generates errors under Red Hat Enterprise Linux 6

50. What port must be opened on the firewall for DNS?
you have access to the correct packages or repositories.
Using the chcon command - you can change the context of a file to work with Apache.
kickstart installations to work
DNS uses port 53.