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 command can be used to view the queue for at service jobs?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
atq
enabled by default
used for kickstart and/or network installs


2. Most boot issues can be resolved by...
defining a %pre section although it is rarely used
entering rescue mode and repairing the problem.
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 gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.


3. Which version of SSH should you use?
The three utilities are: route - ping - and nslookup.
By default - Squid runs on port 3128.
Version 2 is the latest and most secure version of SSH.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.


4. Which log file is used to keep track of policy violations?
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The /var/log/audit/audit.log file contains all policy violations.
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.
The mount command lists all currently mounted file systems.


5. What is the xinetd service used for?
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
you have access to the correct packages or repositories.
service named configtest
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.


6. 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.
The vsftpd package is used to install an FTP server.
The rpm command can operate in install - query - or verify modes.
The /var/log/audit/audit.log file contains all policy violations.


7. Which remote management service is installed by default?Can you name the port that it uses?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
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.
You can use the remove or erase options with yum to remove a package.
You add your action to the end of the /home/user01/.bashrc file.


8. What are the three items that make up LVM?
Physical volumes - volume groups - and logical volumes.
support for TCP Wrappers
run on any port you'd like (provided that port is available)
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.


9. How would you view all Boolean options for the HTTP service?
By defining a %post section - you can run scripts after a kickstart installation is complete.
getsebool -a | grep http
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.


10. What is the superblock used for?
This command reboots virtual guest Client04.
The dig - host - and ping commands can be used to test DNS server functionality.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
rpcbind service


11. 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.
chkconfig sshd off
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
via the command line


12. What is the top command used for?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
This command reboots virtual guest Client04.
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.
Use the top command to view CPU and memory usage.


13. How can you list all services on the system to tell whether they will boot during startup?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
getsebool -a | grep http
chkconfig—list
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.


14. What command can you use to view system processes and their CPU usage?
Use the ps command to view processes and their CPU usage.
The SMTP service runs on TCP port 110.
The mount command lists all currently mounted file systems.
service httpd configtest


15. Before you work with ACLs - what do you need to do to the file system?
LUKS encryption
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The virsh command is used to manage virtual guests.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.


16. What command and option do you use to view the description of Boolean values?
semanage boolean -l
rpmbuild
The service command is used to start - stop - and manage system services.
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.


17. The ____________ is available for each share.
This chapter described tdbsm and smbpasswd back-end authentication.
browseable option
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
Use the ps command to view processes and their CPU usage.


18. How would you go about creating a static route?
Use the ps command to view processes and their CPU usage.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
serve both files and printers to users
Use the route command with the add option to create a static route.


19. What are the three modes in which the rpm command can operate?
The four types of DNS servers are master - slave - caching-only - and forwarding.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
The nfsstat command can be used to view NFS statistics.
The rpm command can operate in install - query - or verify modes.


20. What command can you use to validate the syntax of the Apache config file?
repquota
Network installations can be performed using the HTTP - FTP - and NFS protocols.
load balancing and redundancy benefits
service httpd configtest


21. What is a gateway used for on a network?
useradd -c "Jr Admin" George
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/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.


22. What is NAT - How is it used?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The ping command can be used to verify connectivity to another host.
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.


23. How do you run a command with elevated privileges?
The -t nfs option is used with the mount command to mount NFS resources.
A user's home directory is created under the /home directory.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
generates errors under Red Hat Enterprise Linux 6


24. Do you need to write changes to the disk when using the parted command? What about fdisk?
service sshd statuts
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
getsebool -a | grep http
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.


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

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26. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
The two main config files are master.cf and main.cf.
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.
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.


27. What command can you use to query Boolean values?
getsebool
chkconfig—list
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.


28. The firewall service is...
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.
enabled by default
A user's home directory is created under the /home directory.
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


29. What option is used to allow anonymous uploads to the FTP server?
The htpasswd command can be used to password-protect a web page.
The anonymous_enable=YES option in the main config file allows anonymous uploads.
alternatives --config mta
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.


30. To export directories as resources - what file needs to be edited?

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31. What port does the Apache web server run on - What about HTTPS?
Apache uses port 80 for HTTP and port 443 for HTTPS.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
generates errors under Red Hat Enterprise Linux 6
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.


32. What command can you use to change the context of files?
chcon
createrepo
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 /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.


33. What command can you use to monitor and troubleshoot network connections?
Using the chcon command - you can change the context of a file to work with Apache.
The tcpdump command is used to monitor network connections on different interfaces.
user's home directory in the /etc/skel directory
Sendmail


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

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35. What critical step must you take after updating the kernel to a newer version?
This command reboots virtual guest Client04.
The /etc/fstab file.
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.
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


36. How would you install a group of packages all at a single time?
have the same effect
service httpd configtest
Use the yum groupinstall command to install multiple packages in a single group at once.
By default - Squid runs on port 3128.


37. What does virsh reboot Client04 do?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
support TCP Wrappers
This command reboots virtual guest Client04.
Use the setgid flag to create the appropriate permissions (chmod 2770).


38. GRUB has three stages. Can you name them?
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.
createrepo
defining a %pre section although it is rarely used
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


39. The virt-install package allows you to manage virtual machines _____________. The virt-manager package allows you to manage virtual machines via a GUI interface.
The virsh command is used to manage virtual guests.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
via the command line


40. Does a DHCP server allow reserved IP addresses - If so - how?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The lftp command can be used on a client to test FTP server connections.
The service command is used to start - stop - and manage system services.


41. What are the three different types of RAID described in this chapter?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
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.
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.
load balancing and redundancy benefits


42. Samba servers can...
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.
support for TCP Wrappers
serve both files and printers to users
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.


43. What command is used to create a user for Samba?
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 testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
Apache uses port 80 for HTTP and port 443 for HTTPS.
The smbpasswd command is used to create Samba users.


44. What happens if you call the command from question 3 with the -c option after it has already been run?
support TCP Wrappers
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
alternatives --config mta
The /var/log/audit/audit.log file contains all policy violations.


45. A slave DNS server provides...
load balancing and redundancy benefits
service named configtest
Sendmail
The three utilities are: route - ping - and nslookup.


46. What is the benefit to using centralized authentication?

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47. What option is used with both the fdisk and parted commands to display the current partition tables?
Use the resize2fs command to grow a file system.
The print option is used with both the fdisk and parted commands to display the current partition tables.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.


48. What are SELinux Booleans?
You can use the authconfig-tui command or the authconfig command.
Using the chcon command - you can change the context of a file to work with Apache.
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.
SELinux Booleans provide restrictions to different aspects of a service.


49. For Red Hat Enterprise Linux 6 - SELinux comes set up in enforcing mode. When installing Red Hat Enterprise Linux 5 - you have the option to...

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50. Which file shows you all the client IP addresses?
DNS uses port 53.
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.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.