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


2. What are the two config files for Postfix called?
you have access to the correct packages or repositories.
schedule one-time-only jobs
The two main config files are master.cf and main.cf.
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


3. What command can you use to view NFS statistics?
This command reboots virtual guest Client04.
entering rescue mode and repairing the problem.
The nfsstat command can be used to view NFS statistics.
Network installations can be performed using the HTTP - FTP - and NFS protocols.


4. Are additional packages besides httpd required for a secure website - If so - what are they?
setsebool -P nfs_export_all_rw=1
For Apache to run a secure site - the mod_ssl package is required to be installed.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
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.


5. What port on the firewall needs to be open for the TFTP server to work?
The TFTP server uses UDP port 69.
cat /proc/mdstat
By default - the rndc utility listens on port 953.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.


6. What is the virsh command used for?
The three utilities are: route - ping - and nslookup.
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 virsh command is used to manage virtual guests.
used for kickstart and/or network installs


7. Before you work with ACLs - what do you need to do to the file system?
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
You add your action to the end of the /home/user01/.bashrc file.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.


8. What command can you use to monitor and troubleshoot network connections?
The tcpdump command is used to monitor network connections on different interfaces.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
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.
lvdisplay


9. What command and option can you use to enable a service to start on boot?
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 partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
The TFTP server uses UDP port 69.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.


10. What is NAT - How is it used?
Use the resize2fs command to grow a file system.
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 rndc utility provides a method for managing the DNS server remotely and securely.
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.


11. GRUB has three stages. Can you name them?
chcon
have the same effect
generates errors under Red Hat Enterprise Linux 6
Stage 1: During this stage - the primary bootloader is read into memory by the BIOS from the MBR. Stage 1.5: During this stage - the bootloader is read into memory by the stage 1 bootloader (only if necessary). Stage 2: During this stage - the bootlo


12. What is the top command used for?
chcon
The user_list file can be used to limit which users have access to the FTP server.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
Use the top command to view CPU and memory usage.


13. What is the format of the /etc/shadow file?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
schedule one-time-only jobs
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
The service command is used to start - stop - and manage system services.


14. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
semanage boolean -l
You add your action to the end of the /home/user01/.bashrc file.
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.


15. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
Use the setgid flag to create the appropriate permissions (chmod 2770).
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
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.
choose which mode you'd like it to operate in


16. Samba servers can...
getsebool -a | grep http
The service command is used to start - stop - and manage system services.
serve both files and printers to users
A virtual host is a way of hosting multiple sites using a single IP address.


17. What is a swap? Is it created as a partition or device file?
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.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
The smbstatus command shows you currently mounted Samba resources.


18. You must dictate the ____________ you want allocated to your virtual machine when you create it.
You can use the authconfig-tui command or the authconfig command.
amount of RAM
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The /etc/fstab file.


19. What command can you use to create a new SSL certificate?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
createrepo


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


21. What command can be used to view the queue for at service jobs?
atq
Enforcing during installation
The SMTP service runs on TCP port 110.
The DHCP server listens on port 67 by default.


22. What is the main config file for the DHCP service?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
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.
have the same effect
chkconfig—list


23. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
generates errors under Red Hat Enterprise Linux 6
halts the system
support TCP Wrappers
via the command line


24. What three protocols can you use to perform network installations?
repquota
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.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
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.


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


26. What does the rdnc-confgen command do?
Use the setgid flag to create the appropriate permissions (chmod 2770).
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
schedule one-time-only jobs


27. What port does the Apache web server run on - What about HTTPS?
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
enabled by default
Apache uses port 80 for HTTP and port 443 for HTTPS.
You add your action to the end of the /home/user01/.bashrc file.


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


29. What is the point of using SELinux?
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The SMTP service runs on TCP port 110.
SELinux provides enhanced granular security for the Linux operating system.
Use the ps command to view processes and their CPU usage.


30. What command is used to create an RPM package?
kickstart installations to work
rpmbuild
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
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.


31. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
mkfs.ext4
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.
Use the top command to view CPU and memory usage.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.


32. What command can you use to get information about logical volumes?
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.
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 /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
lvdisplay


33. How can you verify the status of the SSH service after the system has booted?
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.
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.
service sshd statuts
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.


34. What are SELinux Booleans?
SELinux Booleans provide restrictions to different aspects of a service.
Enforcing during installation
This command reboots virtual guest Client04.
The smbpasswd command is used to create Samba users.


35. Where are Yum repository config files located?
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.
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.
getsebool -a | grep http
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.


36. What is the name of the package used to install an FTP?
The vsftpd package is used to install an FTP server.
The htpasswd command can be used to password-protect a web page.
SELinux provides enhanced granular security for the Linux operating system.
Use the yum groupinstall command to install multiple packages in a single group at once.


37. What options with the yum command would you use to remove a package?
You can use the remove or erase options with yum to remove a package.
choose which mode you'd like it to operate in
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.
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.


38. How can you change the security context of a directory to work with Apache?
Using the chcon command - you can change the context of a file to work with Apache.
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 mount command lists all currently mounted file systems.
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.


39. Which file shows you all the client IP addresses?
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The print option is used with both the fdisk and parted commands to display the current partition tables.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
The virsh command is used to manage virtual guests.


40. How can you list all services on the system to tell whether they will boot during startup?
Typing the mail or mutt command allows you to read mail from the command line.
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 gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
chkconfig—list


41. 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.
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.
Sendmail
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.


42. What port does NFS use by default?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
service dhcpd configtest
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
The NFS service uses TCP port 2049 by default.


43. What commands can you use to add a client machine to an LDAP server?
kickstart installations to work
You can use the authconfig-tui command or the authconfig command.
This command reboots virtual guest Client04.
atq


44. What critical step must you take after updating the kernel to a newer version?
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.
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.
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.


45. What command is used to create a user for Samba?
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
The smbpasswd command is used to create Samba users.
The smbstatus command shows you currently mounted Samba resources.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).


46. What is the name of the package that allows you to install VNC?
Using the chcon command - you can change the context of a file to work with Apache.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
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. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
kickstart installations to work
The TFTP server uses UDP port 69.
alternatives --config mta
lvdisplay


48. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
SSH is used for secure remote management of Linux systems.
getsebool -a | grep http
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
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.


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


50. Do you need to write changes to the disk when using the parted command? What about fdisk?
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 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
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.
support for TCP Wrappers