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 does ifconfig 172.168.1.100 netmask 255.255.255.0 eth1 do?
run on any port you'd like (provided that port is available)
The SMTP service runs on TCP port 110.
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.
The ping command can be used to verify connectivity to another host.

2. A service needs to have _______________ to be able to use it.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
The yum and rpm commands are used for package management.
support for TCP Wrappers
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.

3. What happens to jobs that are scheduled to run while the system is off?
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The /etc/hosts file is a local lookup file used to map IP addresses to hostnames if a DNS server isn't available.
chkconfig xinetd --list
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.

4. What commands can you use to add a client machine to an LDAP server?
You can use the authconfig-tui command or the authconfig command.
The three utilities are: route - ping - and nslookup.
service httpd configtest
The two main config files are master.cf and main.cf.

5. What is a gateway used for on a network?
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
Typing the mail or mutt command allows you to read mail from the command line.
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.
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.

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

7. What happens if you call the command from question 3 with the -c option after it has already been run?
The /var/log/audit/audit.log file contains all policy violations.
A user's home directory is created under the /home directory.
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.
The file that stores usernames and their encrypted passwords is erased and replaced with a new file.

8. What option needs to be used with the mount command to mount an NFS resource?
You can use the remove or erase options with yum to remove a package.
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 nfsstat command can be used to view NFS statistics.
The -t nfs option is used with the mount command to mount NFS resources.

9. What is the xinetd service used for?
SELinux provides enhanced granular security for the Linux operating system.
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
chkconfig xinetd --list
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.

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

11. 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.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
The -t nfs option is used with the mount command to mount NFS resources.
The tcpdump command is used to monitor network connections on different interfaces.

12. 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 mount command lists all currently mounted file systems.
SELinux Booleans provide restrictions to different aspects of a service.
The yum and rpm commands are used for package management.

13. How can you display all virtual guests after they're connected to a hypervisor?
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.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
Enforcing during installation
This chapter described tdbsm and smbpasswd back-end authentication.

14. What command can you use to monitor and troubleshoot network connections?
The DHCP server listens on port 67 by default.
The SMTP service runs on TCP port 110.
A virtual host is a way of hosting multiple sites using a single IP address.
The tcpdump command is used to monitor network connections on different interfaces.

15. Before you work with ACLs - what do you need to do to the file system?
service named configtest
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
kickstart installations to work
You can use the authconfig-tui command or the authconfig command.

16. What command and option do you use to view the description of Boolean values?
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.
semanage boolean -l
you have access to the correct packages or repositories.
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.

17. What command do you use to change the permissions on a file or directory - To change ownership?
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.
alternatives --config mta
Enforcing during installation
The htpasswd command can be used to password-protect a web page.

18. What does the partprobe command do?
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
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 partprobe command forces the kernel to reread the partition table. You should always call it after making any changes to your system partitions.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

19. What command can you use to change the context of files?
The SMTP service runs on TCP port 110.
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.
chcon
service dhcpd configtest

20. Runlevel 0 ___________. Runlevel 6 reboots the system.
load balancing and redundancy benefits
The five directories are BUILD - RPMS - SOURCES - SPECS - and SRPMS.
halts the system
Use the ps command to view processes and their CPU usage.

21. To create a RAID or LVM partition using kickstart
atq
The mount command lists all currently mounted file systems.
Kickstart supports both basic and advanced partitioning (RAID/LVM).
Using the chcon command - you can change the context of a file to work with Apache.

22. What command and options can you use to update the time?
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
By default - Squid runs on port 3128.
schedule one-time-only jobs
LUKS encryption

23. What command can you use to check the config file of the DHCP server?
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.
service dhcpd configtest
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

24. What command would you use to create a group - to add the user George to the group?
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
You add your action to the end of the /home/user01/.bashrc file.
repquota
The tcpdump command is used to monitor network connections on different interfaces.

25. What command can you use to create your own repositories?
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/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
The nfsstat command can be used to view NFS statistics.
createrepo

26. By default - what is the path to a user's home directory?

27. What does virsh reboot Client04 do?
This command reboots virtual guest Client04.
The three utilities are: route - ping - and nslookup.
The NFS service uses TCP port 2049 by default.
Use the ps command to view processes and their CPU usage.

28. What directory is used to represent the virtual file system created by the kernel?
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 /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
rpmbuild
The htpasswd command can be used to password-protect a web page.

29. What command can you use to create a new SSL certificate?
atq
For Apache to run a secure site - the mod_ssl package is required to be installed.
browseable option
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

30. GRUB has three stages. Can you name them?
serve both files and printers to users
chkconfig sshd off
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
chkconfig—list

31. What file is used to maintain custom parameters for the kernel during system boot?
Version 2 is the latest and most secure version of SSH.
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 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/sysctl.conf file maintains a list of custom kernel parameters that should be applied during system boot.

32. What are the two config files for Postfix called?
rpcbind service
support TCP Wrappers
The grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.
The two main config files are master.cf and main.cf.

33. What port does NFS use by default?
VNC is used to control a remote desktop session.
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.
kickstart installations to work
The NFS service uses TCP port 2049 by default.

34. What is the point of using SELinux?
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 rndc utility provides a method for managing the DNS server remotely and securely.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
SELinux provides enhanced granular security for the Linux operating system.

35. There are four types of DNS servers. Name them.
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 four types of DNS servers are master - slave - caching-only - and forwarding.
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.
RAID 0 (Striping) - RAID 1 (Mirror) - and RAID 5 (Striping with parity).

36. What is the virsh command used for?
service httpd configtest
The virsh command is used to manage virtual guests.
Use the route command with the add option to create a static route.
service sshd statuts

37. What command is used to create a user for Samba?
The smbpasswd command is used to create Samba users.
Use the ps command to view processes and their CPU usage.
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.
You add your action to the end of the /home/user01/.bashrc file.

38. What command can you use to test connectivity to another host?
lvdisplay
Typing the mail or mutt command allows you to read mail from the command line.
The ping command can be used to verify connectivity to another host.
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

39. What command can you use to manage system services?
The ping command can be used to verify connectivity to another host.
The service command is used to start - stop - and manage system services.
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.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George

40. What is the superblock used for?
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.
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.
For Apache to run a secure site - the mod_ssl package is required to be installed.

41. What does the following firewall rule accomplish: iptables -I INPUT 5 -p tcp -m tcp --dport 80 -j ACCEPT?
The lftp command can be used on a client to test FTP server connections.
Use the top command to view CPU and memory usage.
The user_list file can be used to limit which users have access to the FTP server.
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.

42. What three protocols can you use to perform network installations?
Network installations can be performed using the HTTP - FTP - and NFS protocols.
mkfs.ext4
user's home directory in the /etc/skel directory
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.

43. What port does the Apache web server run on - What about HTTPS?
Apache uses port 80 for HTTP and port 443 for HTTPS.
Use the chkconfig command to enable or disable services during the boot process. The on option enables the service and off disables it.
Use the setgid flag to create the appropriate permissions (chmod 2770).
The virsh command is used to manage virtual guests.

44. The old SysInit scripts have been replaced in Red Hat Enterprise Linux 6 for what new boot utility?
For Apache to run a secure site - the mod_ssl package is required to be installed.
The file system where ACLs will be implemented must be mounted with the acl option before ACLs will work properly.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
entering rescue mode and repairing the problem.

45. What command can you use to query information from the kernel about RAID arrays?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
cat /proc/mdstat
This chapter described tdbsm and smbpasswd back-end authentication.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.

46. What command can be used to view the queue for at service jobs?
atq
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 /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
The last rule is always an implicit deny statement rejecting anything that wasn't matched by previous rules.

47. Samba servers can...
serve both files and printers to users
The DHCP server listens on port 67 by default.
Sendmail
The nfsstat command can be used to view NFS statistics.

48. Can you name the two commands that can be used to view the free space on the system?
Kickstart supports both basic and advanced partitioning (RAID/LVM).
The du and df commands are used to view available space on the system.
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.
entering rescue mode and repairing the problem.

49. Before you work with quotas - what do you need to do to the file system?
load balancing and redundancy benefits
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
entering rescue mode and repairing the problem.
The file system where quotas will be implemented must be mounted with the usrquota and grpquota options before quotas will work properly.

50. Which version of SSH should you use?
You can use the authconfig-tui command or the authconfig command.
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
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.
Version 2 is the latest and most secure version of SSH.