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. How can you check the currently mounted file systems?
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.
support TCP Wrappers
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The mount command lists all currently mounted file systems.

2. What command can you use to test connectivity to another host?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
createrepo
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 ping command can be used to verify connectivity to another host.

3. How can virtual hosts be used?
setsebool -P nfs_export_all_rw=1
The /etc/fstab file.
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.
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.

4. What port does NFS use by default?
The NFS service uses TCP port 2049 by default.
Network installations can be performed using the HTTP - FTP - and NFS protocols.
Enforcing during installation
The vsftpd package is used to install an FTP server.

5. How would you view all Boolean options for the HTTP service?
The SMTP service runs on TCP port 110.
getsebool -a | grep http
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.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.

6. What are the three items that make up LVM?
Physical volumes - volume groups - and logical volumes.
getfacl
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

7. What is the last rule in the iptables file?

8. What is the virsh command used for?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The virsh command is used to manage virtual guests.
VNC is used to control a remote desktop session.
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.

9. What file needs to be edited so that the system will mount a file system at boot time?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The /etc/fstab file.
lvdisplay
Enforcing during installation

10. How can you change the security context of a directory to work with Apache?
A user's home directory is created under the /home directory.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
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.
Using the chcon command - you can change the context of a file to work with Apache.

11. What does virsh reboot Client04 do?
The nfsstat command can be used to view NFS statistics.
alternatives --config mta
This command reboots virtual guest Client04.
useradd -c "Jr Admin" George

12. What three protocols can you use to perform network installations?
atq
Enforcing during installation
lvdisplay
Network installations can be performed using the HTTP - FTP - and NFS protocols.

13. What command can you use to test the config files before starting the DNS service?
You can use the remove or erase options with yum to remove a package.
service named configtest
The print option is used with both the fdisk and parted commands to display the current partition tables.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

14. What are the two config files for Postfix called?
service named configtest
The two main config files are master.cf and main.cf.
For Apache to run a secure site - the mod_ssl package is required to be installed.
getsebool

15. What command can you use to create a file system?
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
mkfs.ext4
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
The virsh command is used to manage virtual guests.

16. What protocols are used with Dovecot?
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS 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.
By defining a %post section - you can run scripts after a kickstart installation is complete.

17. What command (and options) can be used to create a user named George with the description "Jr Admin"?
You can use the remove or erase options with yum to remove a package.
Physical volumes - volume groups - and logical volumes.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
useradd -c "Jr Admin" George

18. What command and option can you use to enable a service to start on boot?
defining a %pre section although it is rarely used
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.
The dig - host - and ping commands can be used to test DNS server functionality.

19. What option is used to allow anonymous uploads to the FTP server?
A virtual host is a way of hosting multiple sites using a single IP address.
SSH is used for secure remote management of Linux systems.
The anonymous_enable=YES option in the main config file allows anonymous uploads.
SELinux provides enhanced granular security for the Linux operating system.

20. A service needs to have _______________ to be able to use it.
ifconfig
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
support for TCP Wrappers
The rndc utility provides a method for managing the DNS server remotely and securely.

21. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
A user's home directory is created under the /home directory.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

22. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
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.
By default - the rndc utility listens on port 953.
Enforcing during installation

23. What command can you use to view NFS statistics?
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.
chcon
The nfsstat command can be used to view NFS statistics.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

24. GRUB has three stages. Can you name them?
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 nfsstat command can be used to view NFS statistics.
repquota
By default - the rndc utility listens on port 953.

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.
The nfsstat command can be used to view NFS statistics.
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 vsftpd package is used to install an FTP server.

26. Which remote management service is installed by default?Can you name the port that it uses?
The mount command lists all currently mounted file systems.
The service command is used to start - stop - and manage system services.
By default - Squid runs on port 3128.
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.

27. What are the two types of back-end authentication mechanisms discussed in this chapter?
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.
mkfs.ext4
This chapter described tdbsm and smbpasswd back-end authentication.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

28. What command can you use to validate the syntax of the Apache config file?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
service httpd configtest
The rndc utility provides a method for managing the DNS server remotely and securely.
The anonymous_enable=YES option in the main config file allows anonymous uploads.

29. What two ports should be opened on the firewall for the FTP server to function properly?
You must open TCP ports 20 and 21 for the FTP server to function properly.
You can use the authconfig-tui command or the authconfig command.
This command reboots virtual guest Client04.
ifconfig

30. Can you name three utilities that can be used for network or DNS client troubleshooting?
entering rescue mode and repairing the problem.
The three utilities are: route - ping - and nslookup.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
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.

31. What critical step must you take after updating the kernel to a newer version?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
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.

32. The ____________ is available for each share.
browseable option
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.
A user's home directory is created under the /home directory.
The user_list file can be used to limit which users have access to the FTP server.

33. Samba servers can...
serve both files and printers to users
You can use the authconfig-tui command or the authconfig command.
The nfsstat command can be used to view NFS statistics.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.

34. Before you work with quotas - what do you need to do to the file system?
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.
used for kickstart and/or network installs
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
For Apache to run a secure site - the mod_ssl package is required to be installed.

35. What benefit does a web proxy provide to your network?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
The TFTP server uses UDP port 69.
The smbpasswd command is used to create Samba users.

36. What are SELinux Booleans?
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
SELinux Booleans provide restrictions to different aspects of a service.
The nfsstat command can be used to view NFS statistics.

37. What command can you use to view mounted Samba shares?
The smbstatus command shows you currently mounted Samba resources.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The TFTP server uses UDP port 69.

38. How do you run a command with elevated privileges?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
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.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.

39. What command can you use to query information from the kernel about RAID arrays?
cat /proc/mdstat
SELinux Booleans provide restrictions to different aspects of a service.
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.
service sshd statuts

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

41. What command is used to show all services being controlled by the xinetd daemon?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
chkconfig xinetd --list
The smbstatus command shows you currently mounted Samba resources.

42. What is the name of the package that allows you to install VNC?
Enforcing during installation
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 superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

43. A slave DNS server provides...
load balancing and redundancy benefits
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
via the command line

44. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
Enforcing during installation
By default - the rndc utility listens on port 953.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
The dig - host - and ping commands can be used to test DNS server functionality.

45. What command do you use to report information on quota usage?
repquota
Use the ps command to view processes and their CPU usage.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
browseable option

46. What command is used to create a user for Samba?
The vsftpd package is used to install an FTP server.
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 smbpasswd command is used to create Samba users.
entering rescue mode and repairing the problem.

47. What is the name of the package used to install an FTP?
getsebool
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
The vsftpd package is used to install an FTP server.
The /var/log/audit/audit.log file contains all policy violations.

48. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
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.
generates errors under Red Hat Enterprise Linux 6
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
Enforcing during installation

49. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The lastlog and faillog commands are used to view user login-related events?
The tcpdump command is used to monitor network connections on different interfaces.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.

50. What command can you use to monitor and troubleshoot network connections?
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The tcpdump command is used to monitor network connections on different interfaces.
via the command line
enabled by default