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 SSH used for?
The three utilities are: route - ping - and nslookup.
user's home directory in the /etc/skel directory
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
SSH is used for secure remote management of Linux systems.


2. What port does the DHCP server listen on by default?
The DHCP server listens on port 67 by default.
The tcpdump command is used to monitor network connections on different interfaces.
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
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.


3. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
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.
The two main config files are master.cf and main.cf.
Use the ps command to view processes and their CPU usage.


4. 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 service command is used to start - stop - and manage system services.
Use the resize2fs command to grow a file system.
You can use the authconfig-tui command or the authconfig command.


5. Most boot issues can be resolved by...
entering rescue mode and repairing the problem.
Typing the mail or mutt command allows you to read mail from the command line.
useradd -c "Jr Admin" George
cat /proc/mdstat


6. What are the three modes in which the rpm command can operate?
The rpm command can operate in install - query - or verify modes.
service named configtest
SELinux Booleans provide restrictions to different aspects of a service.
run on any port you'd like (provided that port is available)


7. Which remote management service is installed by default?Can you name the port that it uses?
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 five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
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.


8. What does virsh reboot Client04 do?
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 last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
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.
This command reboots virtual guest Client04.


9. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
support TCP Wrappers
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/dhcp/dhcpd.conf file is the main config file for the DHCP service.


10. What three protocols can you use to perform network installations?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
SELinux Booleans provide restrictions to different aspects of a service.
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
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.


11. What option would you use to query an installed package using the rpm command?
ifconfig
You can use the -q option to query an installed package. Combining grep and the -qa options - you can search among all installed packages on the system.
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.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.


12. What command do you use to report information on quota usage?
The yum and rpm commands are used for package management.
The mount command lists all currently mounted file systems.
schedule one-time-only jobs
repquota


13. What is the difference between an A record and a PTR record?
The smbstatus command shows you currently mounted Samba resources.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
You add your action to the end of the /home/user01/.bashrc file.
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.


14. What command would you use to create a group - to add the user George to the group?
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 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 groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
have the same effect


15. What command is used to create a user for Samba?
repquota
The smbpasswd command is used to create Samba users.
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.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.


16. What is a virtual host?
This chapter described tdbsm and smbpasswd back-end authentication.
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.
A virtual host is a way of hosting multiple sites using a single IP address.
alternatives --config mta


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

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18. Which file shows you all the client IP addresses?
The four types of DNS servers are master - slave - caching-only - and forwarding.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
You can use the remove or erase options with yum to remove a package.
Use the setgid flag to create the appropriate permissions (chmod 2770).


19. What command can you use to view NFS statistics?
getsebool
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
You can use the remove or erase options with yum to remove a package.
The nfsstat command can be used to view NFS statistics.


20. What file is used to maintain custom parameters for the kernel during system boot?
The DHCP server listens on port 67 by default.
Use the setgid flag to create the appropriate permissions (chmod 2770).
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
SSH is used for secure remote management of Linux systems.


21. What is the xinetd service used for?
Using the chcon command - you can change the context of a file to work with Apache.
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 user_list file can be used to limit which users have access to the FTP server.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.


22. What is NAT - How is it used?
Use the ps command to view processes and their CPU usage.
halts the 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.
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.


23. What command can you use to change the context of files?
service httpd configtest
chcon
VNC is used to control a remote desktop session.
via the command line


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

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25. The exportfs command is used to...
The mount command lists all currently mounted file systems.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
export one or all resources


26. What is the /var/lib/nfs/etab file used for?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
Apache uses port 80 for HTTP and port 443 for HTTPS.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The ping command can be used to verify connectivity to another host.


27. What command can you use to test connectivity to another host?
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.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers 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.
The ping command can be used to verify connectivity to another host.


28. What port does the rndc utility listen on by default?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
service dhcpd configtest
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
By default - the rndc utility listens on port 953.


29. What command (and options) can be used to create a user named George with the description "Jr Admin"?
The TFTP server uses UDP port 69.
By default - Squid runs on port 3128.
useradd -c "Jr Admin" George
chkconfig—list


30. Can you name three utilities that can be used for network or DNS client troubleshooting?
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.
The three utilities are: route - ping - and nslookup.
The smbstatus command shows you currently mounted Samba resources.
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.


31. What command can you use to view the current ACL on a file?
DNS uses port 53.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
getfacl
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.


32. What critical step must you take after updating the kernel to a newer version?
Enforcing during installation
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.
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.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.


33. 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
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.
Physical volumes - volume groups - and logical volumes.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.


34. What does the partprobe command do?
serve both files and printers to users
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
createrepo
The /var/log/audit/audit.log file contains all policy violations.


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

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36. How can you change the security context of a directory to work with Apache?
This command reboots virtual guest Client04.
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.
Using the chcon command - you can change the context of a file to work with Apache.
service sshd statuts


37. How can you check the currently mounted file systems?
getsebool
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The mount command lists all currently mounted file systems.
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.


38. What command is used to create an RPM package?
This command reboots virtual guest Client04.
rpmbuild
The smbpasswd command is used to create Samba users.
have the same effect


39. How would you install a group of packages all at a single time?
The service command is used to start - stop - and manage system services.
mkfs.ext4
Use the yum groupinstall command to install multiple packages in a single group at once.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.


40. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
You add your action to the end of the /home/user01/.bashrc file.
kickstart installations to work
enabled by default
chcon


41. 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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42. You must dictate the ____________ you want allocated to your virtual machine when you create it.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
amount of RAM
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
A user's home directory is created under the /home directory.


43. What command can be used to view the queue for at service jobs?
export one or all resources
The nfsstat command can be used to view NFS statistics.
atq
You must open TCP ports 20 and 21 for the FTP server to function properly.


44. What is PAM used for?
export one or all resources
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.
For Apache to run a secure site - the mod_ssl package is required to be installed.
enabled by default


45. What command can you use to monitor and troubleshoot network connections?
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.
The tcpdump command is used to monitor network connections on different interfaces.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
SELinux Booleans provide restrictions to different aspects of a service.


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

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47. What two ports should be opened on the firewall for the FTP server to function properly?
The SMTP service runs on TCP port 110.
You must open TCP ports 20 and 21 for the FTP server to function properly.
have the same effect
serve both files and printers to users


48. What command do you use to change the permissions on a file or directory - To change ownership?
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.
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.
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 two main config files are master.cf and main.cf.


49. What command and option do you use to view the description of Boolean values?
The print option is used with both the fdisk and parted commands to display the current partition tables.
This chapter described tdbsm and smbpasswd back-end authentication.
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.
semanage boolean -l


50. What three components are needed to fully automate a kickstart installation?
SSH is used for secure remote management of Linux systems.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Network installations can be performed using the HTTP - FTP - and NFS protocols.