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. Samba servers can...
The nfsstat command can be used to view NFS statistics.
serve both files and printers to users
By default - Squid runs on port 3128.
SELinux Booleans provide restrictions to different aspects of a service.


2. What command (and options) can be used to create a user named George with the description "Jr Admin"?
useradd -c "Jr Admin" George
SELinux provides enhanced granular security for the Linux operating system.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.


3. What is the top command used for?
The print option is used with both the fdisk and parted commands to display the current partition tables.
Use the top command to view CPU and memory usage.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.


4. What is the biggest benefit to using LVM over basic partitions?
The print option is used with both the fdisk and parted commands to display the current partition tables.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
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 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.


5. How can virtual hosts be used?
rpmbuild
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 /var/lib/nfs/etab file is used to keep track of currently exported resources.
The NFS service uses TCP port 2049 by default.


6. What benefit does a web proxy provide to your network?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The DHCP server listens on port 67 by default.
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.


7. What file is used to maintain custom parameters for the kernel during system boot?
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.
useradd -c "Jr Admin" George
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 /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.


8. Which remote management service is installed by default?Can you name the port that it uses?
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.
browseable option
The vsftpd package is used to install an FTP server.
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.


9. How would you disable SELinux protection for NFS - allowing shares to be read/write?
setsebool -P nfs_export_all_rw=1
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.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The lftp command can be used on a client to test FTP server connections.


10. What option at the GRUB boot menu can you use to append something to a kernel?
enabled by default
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
SSH is used for secure remote management of Linux systems.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.


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

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12. What command is used to create an RPM package?
service named configtest
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
rpmbuild


13. What client-side command can you use to test your FTP server connection?
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
chkconfig xinetd --list
The lftp command can be used on a client to test FTP server connections.


14. Are additional packages besides httpd required for a secure website - If so - what are they?
For Apache to run a secure site - the mod_ssl package is required to be installed.
getsebool -a | grep http
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.


15. What are the three different types of RAID described in this chapter?
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 grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
Enforcing during installation


16. What option needs to be used with the mount command to mount an NFS resource?
The lastlog and faillog commands are used to view user login-related events?
serve both files and printers to users
The -t nfs option is used with the mount command to mount NFS resources.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.


17. SSH does...
Using the chcon command - you can change the context of a file to work with Apache.
The /var/log/audit/audit.log file contains all policy violations.
support TCP Wrappers
getfacl


18. How can you check the currently mounted file systems?
Use the route command with the add option to create a static route.
The mount command lists all currently mounted file systems.
chkconfig xinetd --list
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


19. How can you verify the status of the SSH service after the system has booted?
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.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
service sshd statuts
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.


20. 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.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
createrepo
This chapter described tdbsm and smbpasswd back-end authentication.


21. Through its main config file - SSH can be configured to...

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22. A slave DNS server provides...
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
load balancing and redundancy benefits
The nfsstat command can be used to view NFS statistics.


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

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24. What is the format of the /etc/shadow file?
service dhcpd configtest
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
service httpd configtest
Sendmail


25. Where are Yum repository config files located?
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 TFTP server uses UDP port 69.
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.
you have access to the correct packages or repositories.


26. What is PAM used for?
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
By default - the rndc utility listens on port 953.
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 /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.


27. By default - what is the path to a user's home directory?

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28. 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.
have the same effect
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
You add your action to the end of the /home/user01/.bashrc file.


29. What is the name of the package that allows you to install VNC?
entering rescue mode and repairing the problem.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
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 /var/lib/nfs/etab file is used to keep track of currently exported resources.


30. 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...
have the same effect
The smbstatus command shows you currently mounted Samba resources.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
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.


31. What option is used with both the fdisk and parted commands to display the current partition tables?
The NFS service uses TCP port 2049 by default.
The print option is used with both the fdisk and parted commands to display the current partition tables.
rpcbind service
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.


32. What is the difference between an A record and a PTR record?
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
service named configtest


33. What are the two config files for Postfix called?
The two main config files are master.cf and main.cf.
The TFTP server uses UDP port 69.
The yum and rpm commands are used for package management.
used for kickstart and/or network installs


34. What two commands are special for dealing with user login events?
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
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.
run on any port you'd like (provided that port is available)
The lastlog and faillog commands are used to view user login-related events?


35. What is the virsh command used for?
schedule one-time-only jobs
The virsh command is used to manage virtual guests.
used for kickstart and/or network installs
cat /proc/mdstat


36. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
The TFTP server uses UDP port 69.
rpcbind service
Apache uses port 80 for HTTP and port 443 for HTTPS.
The /var/log/audit/audit.log file contains all policy violations.


37. How can you display all virtual guests after they're connected to a hypervisor?
Apache uses port 80 for HTTP and port 443 for HTTPS.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The lftp command can be used on a client to test FTP server connections.


38. What command do you use to change the permissions on a file or directory - To change ownership?
service sshd statuts
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.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
SELinux Booleans provide restrictions to different aspects of a service.


39. Red Hat Enterprise Linux 6 is the only version that officially supports _______
mkfs.ext4
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
Using the chcon command - you can change the context of a file to work with Apache.
LUKS encryption


40. What does the partprobe command do?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
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 dig - host - and ping commands can be used to test DNS server functionality.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.


41. What command and option do you use to view the description of Boolean values?
mkfs.ext4
semanage boolean -l
DNS uses port 53.
The nfsstat command can be used to view NFS statistics.


42. What is the name of the section used to run scripts after a kickstart installation?
By defining a %post section - you can run scripts after a kickstart installation is complete.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
lvdisplay
You can use the remove or erase options with yum to remove a package.


43. What is the point of using SELinux?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
The rndc utility provides a method for managing the DNS server remotely and securely.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
SELinux provides enhanced granular security for the Linux operating system.


44. What option can you change in the rsyslog config file to accept remote logs (acting as a centralized logging server)?
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.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
The virsh command is used to manage virtual guests.
cat /proc/mdstat


45. What two ports should be opened on the firewall for the FTP server to function properly?
By default - Squid runs on port 3128.
have the same effect
enabled by default
You must open TCP ports 20 and 21 for the FTP server to function properly.


46. Does a DHCP server allow reserved IP addresses - If so - how?
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 /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
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.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.


47. What command do you use to report information on quota usage?
repquota
createrepo
VNC is used to control a remote desktop session.
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.


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

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49. The firewall service is...
enabled by default
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.
You must open TCP ports 20 and 21 for the FTP server to function properly.
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.


50. Can you name three utilities that can be used for network or DNS client troubleshooting?
A virtual host is a way of hosting multiple sites using a single IP address.
The three utilities are: route - ping - and nslookup.
The lastlog and faillog commands are used to view user login-related events?
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.