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. What is NAT - How is it used?
The lftp command can be used on a client to test FTP server connections.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

2. What command do you use to report information on quota usage?
Apache uses port 80 for HTTP and port 443 for HTTPS.
The lftp command can be used on a client to test FTP server connections.
The rndc utility provides a method for managing the DNS server remotely and securely.
repquota

3. What command can you use to view the current ACL on a file?
Use the yum groupinstall command to install multiple packages in a single group at once.
getfacl
lvdisplay
DNS uses port 53.

4. How can you verify the status of the SSH service after the system has booted?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
service sshd statuts
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

5. What is the point of using SELinux?
Enforcing during installation
The SMTP service runs on TCP port 110.
Use the route command with the add option to create a static route.
SELinux provides enhanced granular security for the Linux operating system.

6. Which remote management service is installed by default?Can you name the port that it uses?
you have access to the correct packages or repositories.
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 web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
Typing the mail or mutt command allows you to read mail from the command line.

7. 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>.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
ifconfig
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.

8. What command and options can you use to update the time?
service named configtest
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
service dhcpd configtest

9. How would you disable SELinux protection for NFS - allowing shares to be read/write?
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 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 nfsstat command can be used to view NFS statistics.
setsebool -P nfs_export_all_rw=1

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

11. What is the difference between an A record and a PTR record?
The four types of DNS servers are master - slave - caching-only - and forwarding.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
By default - Squid runs on port 3128.

12. What is VNC?
service dhcpd configtest
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
The three utilities are: route - ping - and nslookup.
VNC is used to control a remote desktop session.

13. What three components are needed to fully automate a kickstart installation?
used for kickstart and/or network installs
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
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
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.

14. What option would you use to query an installed package using the rpm command?
The print option is used with both the fdisk and parted commands to display the current partition tables.
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 SMTP service runs on TCP port 110.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

15. Red Hat Enterprise Linux 6 is the only version that officially supports _______
defining a %pre section although it is rarely used
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.
LUKS encryption
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.

16. What three protocols can you use to perform network installations?
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
chcon
Network installations can be performed using the HTTP - FTP - and NFS protocols.
DNS uses port 53.

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

18. What command can be used to easily list all the options in the FTP main config file?
defining a %pre section although it is rarely used
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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.

19. The firewall service is...
enabled by default
service httpd configtest
choose which mode you'd like it to operate in
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

20. What command and option can you use to enable a service to start on boot?
alternatives --config mta
By default - the rndc utility listens on port 953.
schedule one-time-only jobs
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.

21. What is the top command used for?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
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 mount command lists all currently mounted file systems.
Use the top command to view CPU and memory usage.

22. What is the superblock used for?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
This command reboots virtual guest Client04.
SELinux Booleans provide restrictions to different aspects of a service.
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.

23. What option is used to allow anonymous uploads to the FTP server?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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.
chkconfig sshd off

24. What command is used to create an RPM package?
rpmbuild
The rpm command can operate in install - query - or verify modes.
The -t nfs option is used with the mount command to mount NFS resources.
By default - the rndc utility listens on port 953.

25. Most boot issues can be resolved by...
atq
This chapter described tdbsm and smbpasswd back-end authentication.
chkconfig—list
entering rescue mode and repairing the problem.

26. What command can you use to validate the syntax of the Apache config file?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
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.
service httpd configtest
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

27. What command (and options) can be used to create a user named George with the description "Jr Admin"?
The user_list file can be used to limit which users have access to the FTP server.
run on any port you'd like (provided that port is available)
DNS uses port 53.
useradd -c "Jr Admin" George

28. What is the name of the package that allows you to install VNC?
choose which mode you'd like it to operate in
chkconfig xinetd --list
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
via the command line

29. What file is used to maintain custom parameters for the kernel during system boot?
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).
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.

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

31. What benefit does a web proxy provide to your network?
The three utilities are: route - ping - and nslookup.
mkfs.ext4
getfacl
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

32. What command can you use to get information about logical volumes?
The du and df commands are used to view available space on the system.
lvdisplay
mkfs.ext4
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.

33. GRUB has three stages. Can you name them?
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.
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
Use the setgid flag to create the appropriate permissions (chmod 2770).
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

34. What is a virtual host?
via the command line
A virtual host is a way of hosting multiple sites using a single IP address.
The rpm command can operate in install - query - or verify modes.
rpcbind service

35. What does virsh reboot Client04 do?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
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
service httpd configtest
This command reboots virtual guest Client04.

36. What is PAM used for?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The service command is used to start - stop - and manage system services.
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.

37. What happens if you call the command from question 3 with the -c option after it has already been run?
defining a %pre section although it is rarely used
The anonymous_enable=YES option in the main config file allows anonymous uploads.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
Sendmail

38. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
The lastlog and faillog commands are used to view user login-related events?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
By default - the rndc utility listens on port 953.
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.

39. 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...

40. How can you list all services on the system to tell whether they will boot during startup?
The /var/log/audit/audit.log file contains all policy violations.
chkconfig—list
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 web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

41. What port on the firewall needs to be open for the TFTP server to work?
The TFTP server uses UDP port 69.
The /var/log/audit/audit.log file contains all policy violations.
halts the system
service dhcpd configtest

42. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
chkconfig sshd off
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
run on any port you'd like (provided that port is available)
Use the setgid flag to create the appropriate permissions (chmod 2770).

43. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
A virtual host is a way of hosting multiple sites using a single IP address.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
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 SMTP service runs on TCP port 110.

44. Are additional packages besides httpd required for a secure website - If so - what are they?
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 htpasswd command can be used to password-protect a web page.
For Apache to run a secure site - the mod_ssl package is required to be installed.
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.

45. What does the partprobe command do?
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.
By default - the rndc utility listens on port 953.
You can use the remove or erase options with yum to remove a package.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

46. What command can you use to change the context of files?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
createrepo
chcon

47. What command disables the SSH service from running when the system boots?
createrepo
chkconfig sshd off
The SMTP service runs on TCP port 110.
chkconfig—list

48. What command do you use to change the permissions on a file or directory - To change ownership?
The rpm command can operate in install - query - or verify modes.
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 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 three utilities are: route - ping - and nslookup.

49. What three commands can you use to help verify that the DNS server is functioning properly?
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
The dig - host - and ping commands can be used to test DNS server functionality.
via the command line
setsebool -P nfs_export_all_rw=1

50. What is the xinetd service used for?
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.
run on any port you'd like (provided that port is available)
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
amount of RAM