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. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
The -t nfs option is used with the mount command to mount NFS resources.
generates errors under Red Hat Enterprise Linux 6
SELinux provides enhanced granular security for the Linux operating system.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.

2. The ______________ for Red Hat Enterprise Linux 5 or 6 includes the use of LVM.
Use the resize2fs command to grow a file system.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
Enforcing during installation
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.

3. What benefit does a web proxy provide to your network?
Typing the mail or mutt command allows you to read mail from the command line.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
The virsh command is used to manage virtual guests.
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.

4. What port does the SMTP service run on?
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 SMTP service runs on TCP port 110.
cat /proc/mdstat
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.

5. What command and options can you use to update the time?
service dhcpd configtest
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
DNS uses port 53.
The yum and rpm commands are used for package management.

6. What command can you use to create a password-protected page?
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 grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
The htpasswd command can be used to password-protect a web page.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

7. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
The virsh command is used to manage virtual guests.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
getsebool -a | grep http
Use the setgid flag to create the appropriate permissions (chmod 2770).

8. Before you work with ACLs - what do you need to do to the file system?
A user's home directory is created under the /home directory.
You can use the authconfig-tui command or the authconfig command.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
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.

9. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
alternatives --config mta
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
You can use the authconfig-tui command or the authconfig command.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.

10. How can you change the security context of a directory to work with Apache?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
Using the chcon command - you can change the context of a file to work with Apache.
cat /proc/mdstat
have the same effect

11. What command do you use to change the permissions on a file or directory - To change ownership?
used for kickstart and/or network installs
The tcpdump command is used to monitor network connections on different interfaces.
You can use the remove or erase options with yum to remove a package.
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.

12. What are the two config files for Postfix called?
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 two main config files are master.cf and main.cf.
This command reboots virtual guest Client04.
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

13. How would you disable SELinux protection for NFS - allowing shares to be read/write?
The -t nfs option is used with the mount command to mount NFS resources.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
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.
setsebool -P nfs_export_all_rw=1

14. How would you install a group of packages all at a single time?
amount of RAM
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
This chapter described tdbsm and smbpasswd back-end authentication.
Use the yum groupinstall command to install multiple packages in a single group at once.

15. What command is used to create a user for Samba?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
mkfs.ext4
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
The smbpasswd command is used to create Samba users.

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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

17. What is PAM used for?
browseable option
rpcbind service
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.
DNS uses port 53.

18. What three protocols can you use to perform network installations?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The mount command lists all currently mounted file systems.
atq
The ping command can be used to verify connectivity to another host.

19. What is the xinetd service used for?
SSH is used for secure remote management of Linux systems.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
A user's home directory is created under the /home directory.
support TCP Wrappers

20. What protocols are used with Dovecot?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
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.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
amount of RAM

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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

22. What is a swap? Is it created as a partition or device file?
SELinux provides enhanced granular security for the Linux operating system.
kickstart installations to work
The dig - host - and ping commands can be used to test DNS server functionality.
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.

23. What command do you use to report information on quota usage?
A user's home directory is created under the /home directory.
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.
repquota
The du and df commands are used to view available space on the system.

24. What is the difference between an A record and a PTR record?
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
The du and df commands are used to view available space on the system.
run on any port you'd like (provided that port is available)
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

25. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
The TFTP server uses UDP port 69.
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.
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/fstab file.

26. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
The rpm command can operate in install - query - or verify modes.
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 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.
rpcbind service

27. What command is used to show all services being controlled by the xinetd daemon?
This command reboots virtual guest Client04.
The print option is used with both the fdisk and parted commands to display the current partition tables.
getsebool -a | grep http
chkconfig xinetd --list

28. How can you list all services on the system to tell whether they will boot during startup?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
chkconfig—list
support for TCP Wrappers
rpcbind service

29. What command can you use to view mounted Samba shares?
chkconfig sshd off
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
The smbstatus command shows you currently mounted Samba resources.

30. What command can be used to easily list all the options in the FTP main config file?
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
you have access to the correct packages or repositories.
The -t nfs option is used with the mount command to mount NFS resources.
The /etc/fstab file.

31. What is a gateway used for on a network?
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.
have the same 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 yum and rpm commands are used for package management.

32. Does a DHCP server allow reserved IP addresses - If so - how?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
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 /var/log/audit/audit.log file contains all policy violations.

33. Can you put your /boot partition on a RAID 5 array?
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
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 ping command can be used to verify connectivity to another host.
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.

34. What are the side effects of shrinking a volume group or logical volume?
The htpasswd command can be used to password-protect a web page.
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 groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
The nfsstat command can be used to view NFS statistics.

35. What are SELinux Booleans?
The SMTP service runs on TCP port 110.
The -t nfs option is used with the mount command to mount NFS resources.
This chapter described tdbsm and smbpasswd back-end authentication.
SELinux Booleans provide restrictions to different aspects of a service.

36. What command can you use to query Boolean values?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
getsebool
entering rescue mode and repairing the problem.
The smbstatus command shows you currently mounted Samba resources.

37. What command can you use to create a new SSL certificate?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
The nfsstat command can be used to view NFS statistics.
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.
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.

38. What critical step must you take after updating the kernel to a newer version?
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.
schedule one-time-only jobs
The user_list file can be used to limit which users have access to the FTP server.
createrepo

39. What command can you use to manage system services?
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
The vsftpd package is used to install an 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.
The service command is used to start - stop - and manage system services.

40. Explain the difference between soft and hard limits in quotas.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

41. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
A virtual host is a way of hosting multiple sites using a single IP address.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
Sendmail
Enforcing during installation

42. Which remote management service is installed by default?Can you name the port that it uses?
ifconfig
rpcbind service
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
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.

43. How can you verify the status of the SSH service after the system has booted?
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
service sshd statuts
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.
By default - the rndc utility listens on port 953.

44. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
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 -t nfs option is used with the mount command to mount NFS resources.
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.

45. What option needs to be used with the mount command to mount an NFS resource?
The -t nfs option is used with the mount command to mount NFS resources.
have the same effect
service sshd statuts
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.

46. What option would you use to query an installed package using the rpm command?
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.
A user's home directory is created under the /home directory.
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.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.

47. What command can you use to monitor and troubleshoot network connections?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
You add your action to the end of the /home/user01/.bashrc file.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
The tcpdump command is used to monitor network connections on different interfaces.

48. 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
useradd -c "Jr Admin" George
chcon
serve both files and printers to users

49. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
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.
mkfs.ext4
Use the yum groupinstall command to install multiple packages in a single group at once.

50. What is the superblock used for?
DNS uses port 53.
By default - the rndc utility listens on port 953.
For Apache to run a secure site - the mod_ssl package is required to be installed.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.