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 command can you use to test connectivity to another host?
The ping command can be used to verify connectivity to another host.
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.
chkconfig xinetd --list
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.

2. What is the difference between an A record and a PTR record?
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
SSH is used for secure remote management of Linux systems.
alternatives --config mta
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.

3. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
support TCP Wrappers
generates errors under Red Hat Enterprise Linux 6
The smbpasswd command is used to create Samba users.
serve both files and printers to users

4. What is the default port that Squid runs on?
By default - Squid runs on port 3128.
mkfs.ext4
Network installations can be performed using the HTTP - FTP - and NFS protocols.
atq

5. What command can you use to query information from the kernel about RAID arrays?
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.
cat /proc/mdstat
Enforcing during installation
Use the top command to view CPU and memory usage.

6. What is the last rule in the iptables file?

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7. What command and option do you use to view the description of Boolean values?
cat /proc/mdstat
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
The /etc/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.
semanage boolean -l

8. A service needs to have _______________ to be able to use it.
support for TCP Wrappers
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
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.
Use the setgid flag to create the appropriate permissions (chmod 2770).

9. What command can you use to change the context of files?
Use the ps command to view processes and their CPU usage.
The NFS service uses TCP port 2049 by default.
chcon
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.

10. Is it possible to share files among groups - What permissions would you set on the directory to accomplish file sharing if possible?
The smbstatus command shows you currently mounted Samba resources.
The /var/log/audit/audit.log file contains all policy violations.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
Use the setgid flag to create the appropriate permissions (chmod 2770).

11. What happens to jobs that are scheduled to run while the system is off?
getsebool
The lastlog and faillog commands are used to view user login-related events?
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 service command is used to start - stop - and manage system services.

12. What three commands can you use to help verify that the DNS server is functioning properly?
The dig - host - and ping commands can be used to test DNS server functionality.
schedule one-time-only jobs
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.
kickstart installations to work

13. Which log file is used to keep track of policy violations?
alternatives --config mta
The /var/log/audit/audit.log file contains all policy violations.
The /etc/fstab file.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514

14. What are the side effects of shrinking a volume group or logical volume?
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.
getsebool -a | grep http
user's home directory in the /etc/skel directory
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

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

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16. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
You must open TCP ports 20 and 21 for the FTP server to function properly.
used for kickstart and/or network installs
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.

17. It is possible to run scripts before a kickstart installation. This is done by...
Using the chcon command - you can change the context of a file to work with Apache.
defining a %pre section although it is rarely used
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.

18. If you want a specific action to take place when user01 logs in to the system - which file would you edit?
Use the route command with the add option to create a static route.
load balancing and redundancy benefits
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.
You add your action to the end of the /home/user01/.bashrc file.

19. If a package is built on an RHEL6 system and deployed to a custom RHEL5 repository - are RHEL5 systems able to use it?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
rpcbind service
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
repquota

20. The at command is used to ____________. The cron service handles reoccurring system jobs.
rpcbind service
The tcpdump command is used to monitor network connections on different interfaces.
SELinux Booleans provide restrictions to different aspects of a service.
schedule one-time-only jobs

21. 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...

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22. What does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The -t nfs option is used with the mount command to mount NFS resources.
load balancing and redundancy benefits
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.

23. What is a gateway used for on a network?
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 lftp command can be used on a client to test FTP server connections.
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 web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

24. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
rpcbind 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 rpm command can operate in install - query - or verify modes.
The two main config files are master.cf and main.cf.

25. What command and options can you use to update the time?
Enforcing during installation
The htpasswd command can be used to password-protect a web page.
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.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.

26. What command would you use to create a group - to add the user George to the group?
VNC is used to control a remote desktop session.
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.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
createrepo

27. What two commands are special for dealing with user login events?
The lastlog and faillog commands are used to view user login-related events?
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
Use the yum groupinstall command to install multiple packages in a single group at once.

28. What does virsh reboot Client04 do?
The DHCP server listens on port 67 by default.
This command reboots virtual guest Client04.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
The NFS service uses TCP port 2049 by default.

29. What two commands are used for package management?
run on any port you'd like (provided that port is available)
A user's home directory is created under the /home directory.
The yum and rpm commands are used for package management.
The vsftpd package is used to install an FTP server.

30. The exportfs command is used to...
ifconfig
This command reboots virtual guest Client04.
export one or all resources
run on any port you'd like (provided that port is available)

31. What command can you use to view system processes and their CPU usage?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
Use the ps command to view processes and their CPU usage.
The /var/log/audit/audit.log file contains all policy violations.

32. What command is used to create a user for Samba?
The smbpasswd command is used to create Samba users.
amount of RAM
The htpasswd command can be used to password-protect a web page.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

33. How can you change the security context of a directory to work with Apache?
atq
Version 2 is the latest and most secure version of SSH.
Using the chcon command - you can change the context of a file to work with Apache.
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.

34. What is the main config file for the DHCP service?
mkfs.ext4
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.
run on any port you'd like (provided that port is available)
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.

35. What command can you use to manage system services?
The service command is used to start - stop - and manage system services.
defining a %pre section although it is rarely used
The smbpasswd command is used to create Samba users.
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

36. What are the three modes in which the rpm command can operate?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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.
choose which mode you'd like it to operate in

37. How can you check the currently mounted file systems?
amount of RAM
ifconfig
The mount command lists all currently mounted file systems.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

38. How would you view all Boolean options for the HTTP service?
getsebool -a | grep http
enabled by default
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

39. What is SSH used for?
The du and df commands are used to view available space on the system.
Use the route command with the add option to create a static route.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
SSH is used for secure remote management of Linux systems.

40. The firewall service is...
The service command is used to start - stop - and manage system services.
enabled by default
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
service httpd configtest

41. What command can you use to create a password-protected page?
enabled by default
The htpasswd command can be used to password-protect a web page.
The TFTP server uses UDP port 69.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.

42. What critical step must you take after updating the kernel to a newer version?
By default - Squid runs on port 3128.
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.
getsebool -a | grep http
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.

43. What command disables the SSH service from running when the system boots?
chkconfig sshd off
cat /proc/mdstat
via the command line
Use the top command to view CPU and memory usage.

44. What is VNC?
SSH is used for secure remote management of Linux systems.
A user's home directory is created under the /home directory.
VNC is used to control a remote desktop session.
The NFS service uses TCP port 2049 by default.

45. 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.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
For Apache to run a secure site - the mod_ssl package is required to be installed.
ifconfig

46. What happens if you call the command from question 3 with the -c option after it has already been run?
you have access to the correct packages or repositories.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
lvdisplay

47. What is NAT - How is it used?
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.
The print option is used with both the fdisk and parted commands to display the current partition tables.
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.

48. What option at the GRUB boot menu can you use to append something to a kernel?
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.
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 defining a %post section - you can run scripts after a kickstart installation is complete.
semanage boolean -l

49. The default SMTP service has been changed from _________ to Postfix in Red Hat Enterprise Linux 6.
The /etc/fstab file.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.
Sendmail
The rpm command can operate in install - query - or verify modes.

50. What is the xinetd service used for?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
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 NFS service uses TCP port 2049 by default.
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.