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 benefit of using public/private key authentication?

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2. What command can you use to create a new SSL certificate?
The two main config files are master.cf and main.cf.
By defining a %post section - you can run scripts after a kickstart installation is complete.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.


3. What port does the rndc utility listen on by default?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
By default - the rndc utility listens on port 953.
The -t nfs option is used with the mount command to mount NFS resources.


4. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
used for kickstart and/or network installs
SELinux provides enhanced granular security for the Linux operating system.
generates errors under Red Hat Enterprise Linux 6
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.


5. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
Enforcing during installation
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
Apache uses port 80 for HTTP and port 443 for HTTPS.


6. What command and option do you use to view the description of Boolean values?
chcon
Using the chcon command - you can change the context of a file to work with Apache.
semanage boolean -l
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.


7. What port does NFS use by default?
service sshd statuts
The vsftpd package is used to install an FTP server.
The NFS service uses TCP port 2049 by default.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.


8. The at command is used to ____________. The cron service handles reoccurring system jobs.
schedule one-time-only jobs
By default - the rndc utility listens on port 953.
The lastlog and faillog commands are used to view user login-related events?
chkconfig xinetd --list


9. The firewall service is...
The virsh command is used to manage virtual guests.
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 SMTP service runs on TCP port 110.
enabled by default


10. 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.
via the command line
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
You must open TCP ports 20 and 21 for the FTP server to function properly.


11. What protocols are used with Dovecot?
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.
getsebool
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The dig - host - and ping commands can be used to test DNS server functionality.


12. What is the benefit to using centralized authentication?

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13. A PXE server eases the automation process but isn't required for...
via the command line
The rpm command can operate in install - query - or verify modes.
schedule one-time-only jobs
kickstart installations to work


14. The package selection screen allows you to install any software you want during the installation process as long as...
lvdisplay
ifconfig
repquota
you have access to the correct packages or repositories.


15. Does a DHCP server allow reserved IP addresses - If so - how?
The /var/log/audit/audit.log file contains all policy violations.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
getsebool -a | grep http
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.


16. What file needs to be edited so that the system will mount a file system at boot time?
Apache uses port 80 for HTTP and port 443 for HTTPS.
The /etc/fstab file.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.


17. How do you run a command with elevated privileges?
Use the setgid flag to create the appropriate permissions (chmod 2770).
amount of RAM
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
entering rescue mode and repairing the problem.


18. What is the /etc/vsftpd/user_list file used for?
The DHCP server listens on port 67 by default.
Enforcing during installation
The user_list file can be used to limit which users have access to the FTP server.
SELinux Booleans provide restrictions to different aspects of a service.


19. Which remote management service is installed by default?Can you name the port that it uses?
Use the setgid flag to create the appropriate permissions (chmod 2770).
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 vsftpd package is used to install an FTP server.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.


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

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21. What are the side effects of shrinking a volume group or logical volume?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
If you shrink a volume group or logical volume - there is a chance you could lose data depending on how much you shrink the volume.
Sendmail


22. Can you name the two commands that can be used to view the free space on the system?
The /var/log/audit/audit.log file contains all policy violations.
The du and df commands are used to view available space on the system.
The print option is used with both the fdisk and parted commands to display the current partition tables.
SSH is used for secure remote management of Linux systems.


23. What is a virtual host?
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.
A virtual host is a way of hosting multiple sites using a single IP address.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
Use the yum groupinstall command to install multiple packages in a single group at once.


24. What are the two types of back-end authentication mechanisms discussed in this chapter?
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
This chapter described tdbsm and smbpasswd back-end authentication.
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.
A user's home directory is created under the /home directory.


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

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26. What are the five required directories when building RPMS?
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 tcpdump command is used to monitor network connections on different interfaces.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.


27. SSH does...
support TCP Wrappers
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
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.


28. What command can be used to easily list all the options in the FTP main config file?
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.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
The mount command lists all currently mounted file systems.


29. What command is used to show all services being controlled by the xinetd daemon?
chkconfig xinetd --list
LUKS encryption
The print option is used with both the fdisk and parted commands to display the current partition tables.
SSH is used for secure remote management of Linux systems.


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

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31. What is the /etc/hosts file used for?

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32. 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...
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
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
have the same effect
The rdnc-confgen command generates an rndc.conf file for the rndc utility.


33. What command can you use to test connectivity to another host?
The user_list file can be used to limit which users have access to the FTP server.
The ping command can be used to verify connectivity to another host.
For Apache to run a secure site - the mod_ssl package is required to be installed.
Use the route command with the add option to create a static route.


34. What is the top command used for?
The service command is used to start - stop - and manage system services.
The virsh command is used to manage virtual guests.
Use the top command to view CPU and memory usage.
getfacl


35. How would you install a group of packages all at a single time?
Use the ps command to view processes and their CPU usage.
Use the yum groupinstall command to install multiple packages in a single group at once.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
useradd -c "Jr Admin" George


36. What is a swap? Is it created as a partition or device file?
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
The lastlog and faillog commands are used to view user login-related events?
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 vsftpd package is used to install an FTP server.


37. What is the name of the section used to run scripts after a kickstart installation?
useradd -c "Jr Admin" George
By defining a %post section - you can run scripts after a kickstart installation is complete.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
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


38. How can you change the security context of a directory to work with Apache?
The smbstatus command shows you currently mounted Samba resources.
Using the chcon command - you can change the context of a file to work with Apache.
cat /proc/mdstat
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.


39. Do you need to write changes to the disk when using the parted command? What about fdisk?
rpmbuild
The mount command lists all currently mounted file systems.
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.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.


40. What command can you use to create a file system?
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.
SELinux provides enhanced granular security for the Linux operating system.
The yum and rpm commands are used for package management.
mkfs.ext4


41. What option needs to be used with the mount command to mount an NFS resource?
You must open TCP ports 20 and 21 for the FTP server to function properly.
The -t nfs option is used with the mount command to mount NFS resources.
atq
chkconfig—list


42. Before you work with ACLs - what do you need to do to the file system?
By default - Squid runs on port 3128.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
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 gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.


43. What directory is used to represent the virtual file system created by the kernel?
The lftp command can be used on a client to test FTP server connections.
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 user_list file can be used to limit which users have access to the FTP server.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.


44. Can you put your /boot partition on a RAID 5 array?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
rpmbuild
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 /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.


45. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
alternatives --config mta
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The anonymous_enable=YES option in the main config file allows anonymous uploads.


46. What is the xinetd service used for?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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.
via the command line
SELinux provides enhanced granular security for the Linux operating system.


47. What command can you use to query Boolean values?
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
getsebool
semanage boolean -l
entering rescue mode and repairing the problem.


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

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49. What command would you use to create a group - to add the user George to the group?
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.
The mount command lists all currently mounted file systems.
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


50. What are SELinux Booleans?
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 last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
SELinux Booleans provide restrictions to different aspects of a service.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.