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?
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.
mkfs.ext4
The dig - host - and ping commands can be used to test DNS server functionality.
support TCP Wrappers

2. How can virtual hosts be used?
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.
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.
The du and df commands are used to view available space on the system.
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.

3. What commands can you use to add a client machine to an LDAP server?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
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>.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

4. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
repquota
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
atq

5. Which file shows you all the client IP addresses?
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
ifconfig
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.
Using the chcon command - you can change the context of a file to work with Apache.

6. What command can you use to create a password-protected page?
The htpasswd command can be used to password-protect a web page.
generates errors under Red Hat Enterprise Linux 6
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
Sendmail

7. Which version of SSH should you use?
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.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
A user's home directory is created under the /home directory.
Version 2 is the latest and most secure version of SSH.

8. Place all files you want added to a _______________ during creation.

9. What port does NFS use by default?
semanage boolean -l
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.
VNC is used to control a remote desktop session.
The NFS service uses TCP port 2049 by default.

10. What command and options can you use to update the time?
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
For Apache to run a secure site - the mod_ssl package is required to be installed.
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.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

11. It is possible to run scripts before a kickstart installation. This is done by...
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
chkconfig sshd off
defining a %pre section although it is rarely used
The yum and rpm commands are used for package management.

12. What is the name of the package that allows you to install VNC?
The ping command can be used to verify connectivity to another host.
schedule one-time-only jobs
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.

13. What is the difference between an A record and a PTR record?
Version 2 is the latest and most secure version of SSH.
getsebool
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.

14. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
defining a %pre section although it is rarely used
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 /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
Sendmail

15. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
entering rescue mode and repairing the problem.
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.
alternatives --config mta
amount of RAM

16. What option is used to allow anonymous uploads to the FTP server?
The dig - host - and ping commands can be used to test DNS server functionality.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The anonymous_enable=YES option in the main config file allows anonymous uploads.

17. Should you allow remote root access - Why or why not?

18. Do you need to write changes to the disk when using the parted command? What about fdisk?
semanage boolean -l
The ping command can be used to verify connectivity to another host.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
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.

19. What port must be opened on the firewall for DNS?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
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.
DNS uses port 53.

20. What command can you use to change the context of files?
kickstart installations to work
By default - the rndc utility listens on port 953.
chcon
rpmbuild

21. What command can you use to view system processes and their CPU usage?
You add your action to the end of the /home/user01/.bashrc file.
Use the ps command to view processes and their CPU usage.
kickstart installations to work
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.

22. What is a virtual host?
browseable option
A virtual host is a way of hosting multiple sites using a single IP address.
SELinux Booleans provide restrictions to different aspects of a service.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.

23. Can you put your /boot partition on a RAID 5 array?
lvdisplay
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.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
entering rescue mode and repairing the problem.

24. Most boot issues can be resolved by...
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
chkconfig xinetd --list
entering rescue mode and repairing the problem.
The dig - host - and ping commands can be used to test DNS server functionality.

25. To grow a file system
LUKS encryption
SELinux provides enhanced granular security for the Linux operating system.
Use the resize2fs command to grow a file system.
Typing the mail or mutt command allows you to read mail from the command line.

26. What command can you use to create a new SSL certificate?
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The lastlog and faillog commands are used to view user login-related events?
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

27. What command can you use to query information from the kernel about RAID arrays?
getsebool -a | grep http
support TCP Wrappers
service dhcpd configtest
cat /proc/mdstat

28. What file needs to be edited so that the system will mount a file system at boot time?
The /etc/fstab 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.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
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

29. 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.
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 mount command lists all currently mounted file systems.
Use the setgid flag to create the appropriate permissions (chmod 2770).

30. What is the name of the section used to run scripts after a kickstart installation?
By defining a %post section - you can run scripts after a kickstart installation is complete.
The three utilities are: route - ping - and nslookup.
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.
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

31. 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.
generates errors under Red Hat Enterprise Linux 6
Use the ps command to view processes and their CPU usage.
chkconfig xinetd --list

32. What command can you use to get information about logical volumes?
useradd -c "Jr Admin" George
lvdisplay
The virsh command is used to manage virtual guests.
The SMTP service runs on TCP port 110.

33. Runlevel 0 ___________. Runlevel 6 reboots the system.
You can use the authconfig-tui command or the authconfig command.
halts the system
setsebool -P nfs_export_all_rw=1
chkconfig—list

34. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
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.
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
used for kickstart and/or network installs
The user_list file can be used to limit which users have access to the FTP server.

35. What command can you use to manage system services?
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 smbpasswd command is used to create Samba users.
The service command is used to start - stop - and manage system services.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.

36. What is the point of using SELinux?
SELinux provides enhanced granular security for the Linux operating system.
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 DHCP server listens on port 67 by default.
The nfsstat command can be used to view NFS statistics.

37. What port does the SMTP service run on?
The SMTP service runs on TCP port 110.
createrepo
cat /proc/mdstat
repquota

38. 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.
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
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

39. What port does the rndc utility listen on by default?
By default - the rndc utility listens on port 953.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
Sendmail
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

40. What is the main config file for the DHCP service?
The vsftpd package is used to install an FTP server.
SELinux Booleans provide restrictions to different aspects of a service.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
Typing the mail or mutt command allows you to read mail from the command line.

41. What three protocols can you use to perform network installations?
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.
support for TCP Wrappers
Network installations can be performed using the HTTP - FTP - and NFS protocols.
service httpd configtest

42. What are the three items that make up LVM?
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.
Physical volumes - volume groups - and logical volumes.
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.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

43. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
ifconfig
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.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

44. What are the two types of back-end authentication mechanisms discussed in this chapter?
repquota
The two main config files are master.cf and main.cf.
serve both files and printers to users
This chapter described tdbsm and smbpasswd back-end authentication.

45. What is the /etc/vsftpd/user_list file used for?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
useradd -c "Jr Admin" George
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.
The user_list file can be used to limit which users have access to the FTP server.

46. What two commands are used for package management?
DNS uses port 53.
The yum and rpm commands are used for package management.
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 /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.

47. What command can you use to monitor and troubleshoot network connections?
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
DNS uses port 53.
The tcpdump command is used to monitor network connections on different interfaces.
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.

48. What does the rdnc-confgen command do?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
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 rdnc-confgen command generates an rndc.conf file for the rndc utility.
setsebool -P nfs_export_all_rw=1

49. The package selection screen allows you to install any software you want during the installation process as long as...
you have access to the correct packages or repositories.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
getfacl
load balancing and redundancy benefits

50. Where are Yum repository config files located?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
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.
service sshd statuts
ifconfig