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. Which file contains all messages generated during installation that can be used for troubleshooting if the need arises?
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
cat /proc/mdstat
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.
enabled by default

2. What command can you use to validate the syntax of the Apache config file?
service httpd configtest
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
cat /proc/mdstat
useradd -c "Jr Admin" George

3. What is the xinetd service used for?
The dig - host - and ping commands can be used to test DNS server functionality.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
useradd -c "Jr Admin" George
The SMTP service runs on TCP port 110.

4. What command can you use to query Boolean values?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
getsebool
service dhcpd configtest
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.

5. In Red Hat Enterprise Linux 6 - the default for SELinux is _______________ (which can be changed after the installation completes). For Red Hat Enterprise Linux 5 - you were able to choose what mode you wanted SELinux to start in.
Enforcing during installation
The user_list file can be used to limit which users have access to the FTP server.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
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.

6. How can you display all virtual guests after they're connected to a hypervisor?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
alternatives --config mta
LUKS encryption
The /etc/fstab file.

7. What command can you use to check the config file of the DHCP server?
You can use the remove or erase options with yum to remove a package.
service dhcpd configtest
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
repquota

8. What port on the firewall needs to be open for the TFTP server to work?
The TFTP server uses UDP port 69.
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.
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.
entering rescue mode and repairing the problem.

9. What is PAM used for?
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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 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.
you have access to the correct packages or repositories.

10. What protocols are used with Dovecot?
getfacl
alternatives --config mta
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
chkconfig—list

11. What command-line program can you use to check your mail?
Use the route command with the add option to create a static route.
Typing the mail or mutt command allows you to read mail from the command line.
The mount command lists all currently mounted file systems.
browseable option

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

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13. 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.
The lftp command can be used on a client to test FTP server connections.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).
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.

14. Most boot issues can be resolved by...
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.
getsebool
The tcpdump command is used to monitor network connections on different interfaces.
entering rescue mode and repairing the problem.

15. What is the main config file for the DHCP service?
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
schedule one-time-only jobs
support for TCP Wrappers
The four types of DNS servers are master - slave - caching-only - and forwarding.

16. How would you install a group of packages all at a single time?
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.
Use the yum groupinstall command to install multiple packages in a single group at once.
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.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.

17. 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.
Using the chcon command - you can change the context of a file to work with Apache.
alternatives --config mta
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.

18. It is possible to run scripts before a kickstart installation. This is done by...
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 /var/lib/nfs/etab file is used to keep track of currently exported resources.
defining a %pre section although it is rarely used
The lastlog and faillog commands are used to view user login-related events?

19. The INPUT chain being used is the default under Red Hat Enterprise Linux 5. This rule...
support for TCP Wrappers
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.
generates errors under Red Hat Enterprise Linux 6
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.

20. What three protocols can you use to perform network installations?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
The tcpdump command is used to monitor network connections on different interfaces.
The /var/log/audit/audit.log file contains all policy violations.
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.

21. What command can you use to view mounted Samba shares?
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 add your action to the end of the /home/user01/.bashrc file.
The smbstatus command shows you currently mounted Samba resources.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

22. Which file shows you all the client IP addresses?
The /var/liv/dhcpd/dhcpd.leases file contains all clients IP address currently in use.
The SMTP service runs on TCP port 110.
The smbstatus command shows you currently mounted Samba resources.
By default - Squid runs on port 3128.

23. What port does the Apache web server run on - What about HTTPS?
The vsftpd package is used to install an FTP server.
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.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
Apache uses port 80 for HTTP and port 443 for HTTPS.

24. What is the /etc/vsftpd/user_list file used for?
By default - the rndc utility listens on port 953.
Use the setgid flag to create the appropriate permissions (chmod 2770).
The user_list file can be used to limit which users have access to the FTP server.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.

25. What command can you use to create a new SSL certificate?
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.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.
Use the route command with the add option to create a static route.
The lastlog and faillog commands are used to view user login-related events?

26. 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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
The partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.

27. What directory is used to represent the virtual file system created by the kernel?
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
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.
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.
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.

28. Red Hat Enterprise Linux 6 is the only version that officially supports _______
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
LUKS encryption

29. The package selection screen allows you to install any software you want during the installation process as long as...
cat /proc/mdstat
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.
you have access to the correct packages or repositories.

30. What command can you use to monitor and troubleshoot network connections?
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
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
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The tcpdump command is used to monitor network connections on different interfaces.

31. 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.
service named configtest
schedule one-time-only jobs
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.

32. What is the name of the package that allows you to install VNC?
chkconfig sshd off
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
The du and df commands are used to view available space on the system.

33. What two commands are used for package management?
The nfsstat command can be used to view NFS statistics.
You can use the remove or erase options with yum to remove a package.
rpcbind service
The yum and rpm commands are used for package management.

34. What is SSH used for?
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
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.

35. What command do you use to change the permissions on a file or directory - To change ownership?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
you have access to the correct packages or repositories.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
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.

36. What command is used to create an RPM package?
rpmbuild
chkconfig—list
The print option is used with both the fdisk and parted commands to display the current partition tables.
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.

37. Does a DHCP server allow reserved IP addresses - If so - how?
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
rpmbuild
The rpm command can operate in install - query - or verify modes.
The NFS service uses TCP port 2049 by default.

38. What port does the rndc utility listen on by default?
export one or all resources
The lastlog and faillog commands are used to view user login-related events?
By default - the rndc utility listens on port 953.
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.

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

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40. Editing the /etc/xinetd.d/tftp file and enabling the service are the same as running the chkconfig tftp on command. Both of these actions...
kickstart installations to work
have the same effect
The vsftpd package is used to install an FTP server.
A user's home directory is created under the /home directory.

41. GRUB has three stages. Can you name them?
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
have the same effect
atq
enabled by default

42. 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.
SSH is used for secure remote management of Linux systems.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
The lastlog and faillog commands are used to view user login-related events?

43. The portmap service was replaced by the ______________ in Red Hat Enterprise Linux 6.
rpcbind service
support for TCP Wrappers
Use the top command to view CPU and memory usage.
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.

44. What option can you change in the rsyslog config file to accept remote logs (acting as a centralized logging server)?
chkconfig xinetd --list
The four types of DNS servers are master - slave - caching-only - and forwarding.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
Enforcing during installation

45. What is the /var/lib/nfs/etab file used for?
choose which mode you'd like it to operate in
You can use the remove or erase options with yum to remove a package.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

46. What is a virtual host?
The DHCP server listens on port 67 by default.
A virtual host is a way of hosting multiple sites using a single IP address.
The SMTP service runs on TCP port 110.
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.

47. What port does the SMTP service run on?
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.
atq
The SMTP service runs on TCP port 110.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

48. A slave DNS server provides...
The vsftpd package is used to install an FTP server.
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
load balancing and redundancy benefits
This chapter described tdbsm and smbpasswd back-end authentication.

49. What critical step must you take after updating the kernel to a newer version?
chkconfig xinetd --list
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.
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.
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.

50. What command and options can you use to update the time?
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.
rpcbind service
serve both files and printers to users
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.