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 happens if you call the command from question 3 with the -c option after it has already been run?
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
By default - the rndc utility listens on port 953.
user's home directory in the /etc/skel directory

2. What does it mean if you ping a host and you receive the response Destination Unreachable?
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
A virtual host is a way of hosting multiple sites using a single IP address.
The -t nfs option is used with the mount command to mount NFS resources.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

3. What file is used to maintain custom parameters for the kernel during system boot?
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 chcon command - you can change the context of a file to work with Apache.
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/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.

4. What are the two types of back-end authentication mechanisms discussed in this chapter?
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
Enforcing during installation
This chapter described tdbsm and smbpasswd back-end authentication.
The lastlog and faillog commands are used to view user login-related events?

5. What is NAT - How is it used?
By defining a %post section - you can run scripts after a kickstart installation is complete.
have the same effect
DNS uses port 53.
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.

6. A PXE server eases the automation process but isn't required for...
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 three utilities are: route - ping - and nslookup.
kickstart installations to work
The NFS service uses TCP port 2049 by default.

7. What is the /var/lib/nfs/etab file used for?
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.
atq
have the same effect
The /var/lib/nfs/etab file is used to keep track of currently exported resources.

8. What command can be used to view the queue for at service jobs?
used for kickstart and/or network installs
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
atq
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.

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

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10. What is the name of the package that allows you to install VNC?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
support for TCP Wrappers
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

11. What command is used to create a user for Samba?
via the command line
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
VNC is used to control a remote desktop session.
The smbpasswd command is used to create Samba users.

12. 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.
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.
getsebool
have the same effect

13. What three protocols can you use to perform network installations?
load balancing and redundancy benefits
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
The vsftpd package is used to install an FTP server.
Network installations can be performed using the HTTP - FTP - and NFS protocols.

14. What options with the yum command would you use to remove a package?
You can use the remove or erase options with yum to remove a package.
This command reboots virtual guest Client04.
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.
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.

15. 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
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
chcon
you have access to the correct packages or repositories.

16. Runlevel 0 ___________. Runlevel 6 reboots the system.
The service command is used to start - stop - and manage system services.
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
halts the system
Version 2 is the latest and most secure version of SSH.

17. How can you verify the status of the SSH service after the system has booted?
Use the route command with the add option to create a static route.
schedule one-time-only jobs
The dig - host - and ping commands can be used to test DNS server functionality.
service sshd statuts

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

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19. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
alternatives --config mta
The print option is used with both the fdisk and parted commands to display the current partition tables.
The three utilities are: route - ping - and nslookup.
You can use the remove or erase options with yum to remove a package.

20. How would you disable SELinux protection for NFS - allowing shares to be read/write?
rpmbuild
The two main config files are master.cf and main.cf.
setsebool -P nfs_export_all_rw=1
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.

21. What command can you use to validate the syntax of the Apache config file?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
service httpd configtest
Physical volumes - volume groups - and logical volumes.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

22. What is the difference between an ext2 and ext3 file system?

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23. What happens to jobs that are scheduled to run while the system is off?
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.
The rndc utility provides a method for managing the DNS server remotely and securely.
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 smbstatus command shows you currently mounted Samba resources.

24. Can you put your /boot partition on a RAID 5 array?
The SMTP service runs on TCP port 110.
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.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

25. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
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.
Sendmail
Use the resize2fs command to grow a file system.
kickstart installations to work

26. What command can you use to test connectivity to another host?
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The ping command can be used to verify connectivity to another host.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
load balancing and redundancy benefits

27. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
rpcbind service
Using the chcon command - you can change the context of a file to work with Apache.
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.
chcon

28. What are the three items that make up LVM?
The -t nfs option is used with the mount command to mount NFS resources.
The NFS service uses TCP port 2049 by default.
Enforcing during installation
Physical volumes - volume groups - and logical volumes.

29. How can virtual hosts be used?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
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.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
Sendmail

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

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31. There are four types of DNS servers. Name them.
mkfs.ext4
The four types of DNS servers are master - slave - caching-only - and forwarding.
The three utilities are: route - ping - and nslookup.
used for kickstart and/or network installs

32. What is the name of the section used to run scripts after a kickstart installation?
getsebool
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
By defining a %post section - you can run scripts after a kickstart installation is complete.

33. What command can you use to create a new SSL certificate?
rpmbuild
The htpasswd command can be used to password-protect a web page.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

34. What command can you use to view the current ACL on a file?
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
getfacl
Version 2 is the latest and most secure version of SSH.
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.

35. Which version of SSH should you use?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
Version 2 is the latest and most secure version of SSH.
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
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

36. What port does the Apache web server run on - What about HTTPS?
The virsh command is used to manage virtual guests.
The tcpdump command is used to monitor network connections on different interfaces.
getsebool -a | grep http
Apache uses port 80 for HTTP and port 443 for HTTPS.

37. What command can you use to monitor and troubleshoot network connections?
The tcpdump command is used to monitor network connections on different interfaces.
The ping command can be used to verify connectivity to another host.
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.
Use the resize2fs command to grow a file system.

38. The at command is used to ____________. The cron service handles reoccurring system jobs.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
mkfs.ext4
The user_list file can be used to limit which users have access to the FTP server.
schedule one-time-only jobs

39. What three commands can you use to help verify that the DNS server is functioning properly?
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 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 dig - host - and ping commands can be used to test DNS server functionality.
You can use the authconfig-tui command or the authconfig command.

40. A slave DNS server provides...
user's home directory in the /etc/skel directory
load balancing and redundancy benefits
The tcpdump command is used to monitor network connections on different interfaces.
chkconfig xinetd --list

41. What is SSH used for?
have the same effect
SSH is used for secure remote management of Linux systems.
The rpm command can operate in install - query - or verify modes.
The /var/log/audit/audit.log file contains all policy violations.

42. How can you check the currently mounted file systems?
The mount command lists all currently mounted file systems.
The three utilities are: route - ping - and nslookup.
Use the yum groupinstall command to install multiple packages in a single group at once.
useradd -c "Jr Admin" George

43. What command disables the SSH service from running when the system boots?
chkconfig xinetd --list
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
SSH is used for secure remote management of Linux systems.
chkconfig sshd off

44. What command can you use to query Boolean values?
amount of RAM
getsebool
cat /proc/mdstat
SELinux provides enhanced granular security for the Linux operating system.

45. What command can you use to create your own repositories?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
SSH is used for secure remote management of Linux systems.
createrepo
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.

46. What are the three modes in which the rpm command can operate?
The rpm command can operate in install - query - or verify modes.
chkconfig—list
The lftp command can be used on a client to test FTP server connections.
The tcpdump command is used to monitor network connections on different interfaces.

47. What port must be opened on the firewall for DNS?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
DNS uses port 53.
A virtual host is a way of hosting multiple sites using a single IP address.

48. What port does the DHCP server listen on by default?
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
semanage boolean -l
Physical volumes - volume groups - and logical volumes.
The DHCP server listens on port 67 by default.

49. What command can you use to check the config file of the DHCP server?
service dhcpd configtest
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 vsftpd package is used to install an FTP server.
The du and df commands are used to view available space on the system.

50. The firewall service is...
enabled by default
The SMTP service runs on TCP port 110.
mkfs.ext4
entering rescue mode and repairing the problem.