Test your basic knowledge |

RHCSA

Subjects : certifications, it-skills, 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. In Red Hat Enterprise Linux 6 - the default for SELinux is _______________ (which can be changed after the installation completes). For Red Hat Enterprise Linux 5 - you were able to choose what mode you wanted SELinux to start in.
halts the system
Enforcing during installation
kickstart installations to work
The two main config files are master.cf and main.cf.

2. What command can you use to test connectivity to another host?
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 format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
The ping command can be used to verify connectivity to another host.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.

3. 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
run on any port you'd like (provided that port is available)
For Apache to run a secure site - the mod_ssl package is required to be installed.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

4. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
The user_list file can be used to limit which users have access to the FTP server.
You must open TCP ports 20 and 21 for the FTP server to function properly.
via the command line
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.

5. What are the two types of back-end authentication mechanisms discussed in this chapter?
The virsh command is used to manage virtual guests.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
This chapter described tdbsm and smbpasswd back-end authentication.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.

6. 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.
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 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.
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.

7. What are the three items that make up LVM?
getsebool
chkconfig xinetd --list
You must open TCP ports 20 and 21 for the FTP server to function properly.
Physical volumes - volume groups - and logical volumes.

8. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
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.
alternatives --config mta
The rndc utility provides a method for managing the DNS server remotely and securely.
You add your action to the end of the /home/user01/.bashrc file.

9. How would you install a group of packages all at a single time?
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.
The smbstatus command shows you currently mounted Samba resources.
By default - Squid runs on port 3128.
Use the yum groupinstall command to install multiple packages in a single group at once.

10. What port does the SMTP service run on?
Sendmail
The SMTP service runs on TCP port 110.
Enforcing during installation
entering rescue mode and repairing the problem.

11. What command can you use to check the config file of the DHCP server?
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.
chkconfig xinetd --list
schedule one-time-only jobs

12. What command is used to create an RPM package?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
rpmbuild
setsebool -P nfs_export_all_rw=1
The /etc/fstab file.

13. What is the name of the package used to install an FTP?
You must open TCP ports 20 and 21 for the FTP server to function properly.
entering rescue mode and repairing the problem.
The vsftpd package is used to install an FTP server.
The TFTP server uses UDP port 69.

14. A PXE server eases the automation process but isn't required for...
setsebool -P nfs_export_all_rw=1
kickstart installations to work
SSH is used for secure remote management of Linux systems.
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.

15. A slave DNS server provides...
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
SELinux provides enhanced granular security for the Linux operating system.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
load balancing and redundancy benefits

16. What port does the rndc utility listen on by default?
The rndc utility provides a method for managing the DNS server remotely and securely.
By default - the rndc utility listens on port 953.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
The smbpasswd command is used to create Samba users.

17. What two commands are used for package management?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
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.
The yum and rpm commands are used for package management.
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

18. What is the /etc/vsftpd/user_list file used for?
have the same effect
entering rescue mode and repairing the problem.
The user_list file can be used to limit which users have access to the FTP server.
support TCP Wrappers

19. The virt-install package allows you to manage virtual machines _____________. The virt-manager package allows you to manage virtual machines via a GUI interface.
via the command line
atq
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

20. 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...

21. What option is used with both the fdisk and parted commands to display the current partition tables?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The print option is used with both the fdisk and parted commands to display the current partition tables.
user's home directory in the /etc/skel directory
rpcbind service

22. There are four types of DNS servers. Name them.
getsebool
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.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The four types of DNS servers are master - slave - caching-only - and forwarding.

23. What is the default port that Squid runs on?
SELinux provides enhanced granular security for the Linux operating system.
By default - Squid runs on port 3128.
The lastlog and faillog commands are used to view user login-related events?
Typing the mail or mutt command allows you to read mail from the command line.

24. How would you disable SELinux protection for NFS - allowing shares to be read/write?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
setsebool -P nfs_export_all_rw=1
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The rdnc-confgen command generates an rndc.conf file for the rndc utility.

25. How can you display all virtual guests after they're connected to a hypervisor?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
By default - the rndc utility listens on port 953.
chkconfig sshd off
The tcpdump command is used to monitor network connections on different interfaces.

26. 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>.
By default - Squid runs on port 3128.
A virtual host is a way of hosting multiple sites using a single IP address.
kickstart installations to work

27. What are the three different types of RAID described in this chapter?
SSH is used for secure remote management of Linux systems.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Typing the mail or mutt command allows you to read mail from the command line.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

28. What commands can you use to add a client machine to an LDAP server?
A virtual host is a way of hosting multiple sites using a single IP address.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
You can use the authconfig-tui command or the authconfig command.
The DHCP server listens on port 67 by default.

29. The package selection screen allows you to install any software you want during the installation process as long as...
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.
you have access to the correct packages or repositories.
Physical volumes - volume groups - and logical volumes.
A user's home directory is created under the /home directory.

30. What is the top command used for?
Use the setgid flag to create the appropriate permissions (chmod 2770).
Use the top command to view CPU and memory usage.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
have the same effect

31. Runlevel 0 ___________. Runlevel 6 reboots the system.
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.
halts the system
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP 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.

32. What command can you use to change the context of files?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The print option is used with both the fdisk and parted commands to display the current partition tables.
createrepo
chcon

33. What directory is used to represent the virtual file system created by the kernel?
Use the setgid flag to create the appropriate permissions (chmod 2770).
This chapter described tdbsm and smbpasswd back-end authentication.
The yum and rpm commands are used for package management.
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.

34. Can you name the two commands that can be used to view the free space on the system?
The du and df commands are used to view available space on the system.
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 three utilities are: route - ping - and nslookup.
Version 2 is the latest and most secure version of SSH.

35. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
The two main config files are master.cf and main.cf.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
Use the setgid flag to create the appropriate permissions (chmod 2770).
load balancing and redundancy benefits

36. What does it mean if you ping a host and you receive the response Destination Unreachable?
Physical volumes - volume groups - and logical volumes.
lvdisplay
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.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

37. Before you work with quotas - what do you need to do to the file system?
setsebool -P nfs_export_all_rw=1
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
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.

38. What option can you change in the rsyslog config file to accept remote logs (acting as a centralized logging server)?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
By defining a %post section - you can run scripts after a kickstart installation is complete.
enabled by default
entering rescue mode and repairing the problem.

39. What is NAT - How is it used?
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
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.
Version 2 is the latest and most secure version of SSH.
ifconfig

40. To create a RAID or LVM partition using kickstart
Kickstart supports both basic and advanced partitioning (RAID/LVM).
VNC is used to control a remote desktop session.
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
you have access to the correct packages or repositories.

41. Where are Yum repository config files located?
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 file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
You add your action to the end of the /home/user01/.bashrc file.
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.

42. The exportfs command is used to...
The du and df commands are used to view available space on 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.
export one or all resources
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.

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

44. What is the biggest benefit to using LVM over basic partitions?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
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.
Use the ps command to view processes and their CPU usage.

45. How can you list all services on the system to tell whether they will boot during startup?
chkconfig—list
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.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
serve both files and printers to users

46. How can virtual hosts be used?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
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.
Use the setgid flag to create the appropriate permissions (chmod 2770).

47. Samba servers can...
The rpm command can operate in install - query - or verify modes.
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
You must open TCP ports 20 and 21 for the FTP server to function properly.
serve both files and printers to users

48. What does S12rsyslog in the /etc/rc.d/rc2.d directory mean?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
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.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

49. What happens if you call the command from question 3 with the -c option after it has already been run?
You can use the remove or erase options with yum to remove a package.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
DNS uses port 53.
For Apache to run a secure site - the mod_ssl package is required to be installed.

50. How would you go about creating a static route?
The virsh command is used to manage virtual guests.
Use the route command with the add option to create a static route.
halts the system
The NFS service uses TCP port 2049 by default.