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. There are four types of DNS servers. Name them.
chkconfig xinetd --list
The four types of DNS servers are master - slave - caching-only - and forwarding.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
The anonymous_enable=YES option in the main config file allows anonymous uploads.

2. What command can you use to query information from the kernel about RAID arrays?
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
LUKS encryption
cat /proc/mdstat
createrepo

3. Before you work with quotas - what do you need to do to the file system?
You can use the authconfig-tui command or the authconfig command.
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 smbstatus command shows you currently mounted Samba resources.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

4. A slave DNS server provides...
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
load balancing and redundancy benefits
By default - the rndc utility listens on port 953.
VNC is used to control a remote desktop session.

5. What command is used to show all services being controlled by the xinetd daemon?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
chkconfig xinetd --list
browseable option
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

6. What command would you use to create a group - to add the user George to the group?
Use the setgid flag to create the appropriate permissions (chmod 2770).
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
used for kickstart and/or network installs

7. What are SELinux Booleans?
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
mkfs.ext4
SELinux Booleans provide restrictions to different aspects of a service.
support TCP Wrappers

8. How would you view all Boolean options for the HTTP service?
getsebool -a | grep http
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
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 SMTP service runs on TCP port 110.

9. What port on the firewall needs to be open for the TFTP server to work?
Enforcing during installation
service httpd configtest
Enforcing during installation
The TFTP server uses UDP port 69.

10. What command displays your current interfaces and IP address?
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 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.
Version 2 is the latest and most secure version of SSH.
ifconfig

11. How would you disable SELinux protection for NFS - allowing shares to be read/write?
setsebool -P nfs_export_all_rw=1
getsebool
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
Physical volumes - volume groups - and logical volumes.

12. What three commands can you use to help verify that the DNS server is functioning properly?
run on any port you'd like (provided that port is available)
You can use the authconfig-tui command or the authconfig command.
The dig - host - and ping commands can be used to test DNS server functionality.
The nfsstat command can be used to view NFS statistics.

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

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14. What option is used with both the fdisk and parted commands to display the current partition tables?
The yum and rpm commands are used for package management.
The print option is used with both the fdisk and parted commands to display the current partition tables.
useradd -c "Jr Admin" George
You can use the remove or erase options with yum to remove a package.

15. What happens to jobs that are scheduled to run while the system is off?
Use the setgid flag to create the appropriate permissions (chmod 2770).
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
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.
LUKS encryption

16. What command can you use to test connectivity to another host?
serve both files and printers to users
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
getsebool
The ping command can be used to verify connectivity to another host.

17. Do you need to write changes to the disk when using the parted command? What about fdisk?
enabled by default
service httpd configtest
The virsh command is used to manage virtual guests.
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.

18. Can you name the two commands that can be used to view the free space on the system?
Using the chcon command - you can change the context of a file to work with Apache.
The du and df commands are used to view available space on the system.
By defining a %post section - you can run scripts after a kickstart installation is complete.
Use the resize2fs command to grow a file system.

19. What is NAT - How is it used?
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.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers 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.
LUKS encryption

20. What is the biggest benefit to using LVM over basic partitions?
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
have the same effect
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.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.

21. What is PAM used for?
service sshd statuts
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.
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.
SSH is used for secure remote management of Linux systems.

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.
generates errors under Red Hat Enterprise Linux 6
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
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.

23. What is the top command used for?
SELinux Booleans provide restrictions to different aspects of a service.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
chkconfig sshd off
Use the top command to view CPU and memory usage.

24. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
The smbstatus command shows you currently mounted Samba resources.
Using the chcon command - you can change the context of a file to work with Apache.
Sendmail
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

25. What option is used to allow anonymous uploads to the 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.
Using the chcon command - you can change the context of a file to work with Apache.
user's home directory in the /etc/skel directory
The anonymous_enable=YES option in the main config file allows anonymous uploads.

26. What command can you use to view mounted Samba shares?
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
The smbstatus command shows you currently mounted Samba resources.
The du and df commands are used to view available space on the system.
Use the setgid flag to create the appropriate permissions (chmod 2770).

27. What is the /var/lib/nfs/etab file used for?
Physical volumes - volume groups - and logical volumes.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
SELinux provides enhanced granular security for the Linux operating system.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

28. What is a gateway used for on a network?
The lftp command can be used on a client to test FTP server connections.
The superblock is a structure that contains metadata of the file system. If this becomes corrupt - you are in trouble.
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.
VNC is used to control a remote desktop session.

29. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
generates errors under Red Hat Enterprise Linux 6
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.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
user's home directory in the /etc/skel directory

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

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31. What command can you use to validate the syntax of the Apache config file?
service httpd configtest
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
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.

32. GRUB has three stages. Can you name them?
createrepo
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.
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
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George

33. What is the difference between the update (-U) and install (-i) options when using rpm to update the kernel?
getsebool -a | grep http
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.
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 rdnc-confgen command generates an rndc.conf file for the rndc utility.

34. What is the main config file for the DHCP service?
getsebool
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
Use the route command with the add option to create a static route.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

35. What is the format of the /etc/shadow file?
The service command is used to start - stop - and manage system services.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
The SMTP service runs on TCP port 110.

36. What option at the GRUB boot menu can you use to append something to a kernel?
setsebool -P nfs_export_all_rw=1
The three utilities are: route - ping - and nslookup.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

37. What is a virtual host?
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.
enabled by default
A virtual host is a way of hosting multiple sites using a single IP address.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.

38. What is a swap? Is it created as a partition or device file?
Sendmail
halts the system
getfacl
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.

39. What two ports should be opened on the firewall for the FTP server to function properly?
Use the yum groupinstall command to install multiple packages in a single group at once.
Use the route command with the add option to create a static route.
You must open TCP ports 20 and 21 for the FTP server to function properly.
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.

40. What are the side effects of shrinking a volume group or logical volume?
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
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.
The tcpdump command is used to monitor network connections on different interfaces.
ifconfig

41. What are the two config files for Postfix called?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
service dhcpd configtest
The two main config files are master.cf and main.cf.
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.

42. What file is used to maintain custom parameters for the kernel during system boot?
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
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 /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
The lftp command can be used on a client to test FTP server connections.

43. What command disables the SSH service from running when the system boots?
repquota
The smbstatus command shows you currently mounted Samba resources.
The tcpdump command is used to monitor network connections on different interfaces.
chkconfig sshd off

44. 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.
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.
service httpd configtest
SSH is used for secure remote management of Linux systems.

45. What happens if a host changes its IP address and the keys don't match?

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46. What port does the rndc utility listen on by default?
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.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
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.
By default - the rndc utility listens on port 953.

47. 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.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
support for TCP Wrappers
The anonymous_enable=YES option in the main config file allows anonymous uploads.

48. Are additional packages besides httpd required for a secure website - If so - what are they?
For Apache to run a secure site - the mod_ssl package is required to be installed.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
rpcbind service
DNS uses port 53.

49. What benefit does a web proxy provide to your network?
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 chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

50. What is the default port that Squid runs on?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
Apache uses port 80 for HTTP and port 443 for HTTPS.
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
By default - Squid runs on port 3128.