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?
The -t nfs option is used with the mount command to mount NFS resources.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
service httpd configtest
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.

2. What is SSH used for?
Sendmail
SSH is used for secure remote management of Linux systems.
The rdnc-confgen command generates an rndc.conf file for the rndc utility.
You can use the remove or erase options with yum to remove a package.

3. 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.
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
load balancing and redundancy benefits
The yum and rpm commands are used for package management.

4. What is a swap? Is it created as a partition or device file?
The testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.
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 four types of DNS servers are master - slave - caching-only - and forwarding.
A user's home directory is created under the /home directory.

5. What command can you use to view system processes and their CPU usage?
service sshd statuts
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.
Use the ps command to view processes and their CPU usage.
The rndc utility provides a method for managing the DNS server remotely and securely.

6. How can you list all services on the system to tell whether they will boot during startup?
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
Use the top command to view CPU and memory usage.
The /etc/dhcp/dhcpd.conf file is the main config file for the DHCP service.
chkconfig—list

7. What commands can you use to add a client machine to an LDAP server?
The xinetd daemon is used to control and/or run multiple system services. One example is a TFTP server.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.
You can use the authconfig-tui command or the authconfig command.
semanage boolean -l

8. What file needs to be edited so that the system will mount a file system at boot time?
rpcbind service
The /etc/fstab file.
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 grep -v ^# /etc/vsftpd/vsftpd.conf command shows you all the options currently being used with the FTP server.

9. You must dictate the ____________ you want allocated to your virtual machine when you create it.
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
amount of RAM
chkconfig—list
By entering the GRUB boot menu - you can choose the a option to append something to the kernel command-line options.

10. What are the three items that make up LVM?
Physical volumes - volume groups - and logical volumes.
Use the resize2fs command to grow a file system.
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 three utilities are: route - ping - and nslookup.

11. What are the side effects of shrinking a volume group or logical volume?
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 mount command lists all currently mounted file systems.
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.
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

12. What port does the rndc utility listen on by default?
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.
By default - the rndc utility listens on port 953.
cat /proc/mdstat
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.

13. What option is used with both the fdisk and parted commands to display the current partition tables?
The print option is used with both the fdisk and parted commands to display the current partition tables.
An ext3 file system has journaling built in to it - whereas the ext2 file system doesn't.
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.

14. What is the /etc/vsftpd/user_list file used for?
Apache uses port 80 for HTTP and port 443 for HTTPS.
The user_list file can be used to limit which users have access to the FTP server.
The -t nfs option is used with the mount command to mount NFS resources.
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.

15. What option is used to allow anonymous uploads to the FTP server?
The anonymous_enable=YES option in the main config file allows anonymous uploads.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
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 print option is used with both the fdisk and parted commands to display the current partition tables.

16. What critical step must you take after updating the kernel to a newer version?
The lftp command can be used on a client to test FTP server connections.
Use the route command with the add option to create a static route.
The htpasswd command can be used to password-protect a web page.
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 are the three modes in which the rpm command can operate?
The du and df commands are used to view available space on the system.
The rpm command can operate in install - query - or verify modes.
have the same effect
getsebool

18. To export directories as resources - what file needs to be edited?

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19. What is the biggest benefit to using LVM over basic partitions?
Use the ps command to view processes and their CPU usage.
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.
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
By default - the rndc utility listens on port 953.

20. 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.
service sshd statuts
Enforcing during installation
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.
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.

21. What command do you use to report information on quota usage?
repquota
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.
This chapter described tdbsm and smbpasswd back-end authentication.
Use the /usr/share/doc/dovecot-1.0.7/examples/mkcert.sh command after editing the /etc/pki/dovecot/dovecot-openssl.cnf file.

22. What port does the Apache web server run on - What about HTTPS?
Apache uses port 80 for HTTP and port 443 for HTTPS.
By using centralized authentication - you don't need to re-create or maintain multiple accounts across every system in your organization.
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.
By default - Squid runs on port 3128.

23. A PXE server eases the automation process but isn't required for...
The VNC package for Red Hat Enterprise Linux 6 is tiger-vnc.
The du and df commands are used to view available space on the system.
Sendmail
kickstart installations to work

24. What command (and options) can be used to create a user named George with the description "Jr Admin"?
useradd -c "Jr Admin" George
The /proc directory. The /proc/sys directory is the place where you actually tune kernel parameters.
Version 2 is the latest and most secure version of SSH.
The yum and rpm commands are used for package management.

25. The virt-install package allows you to manage virtual machines _____________. The virt-manager package allows you to manage virtual machines via a GUI interface.
DNS uses port 53.
kickstart installations to work
The anonymous_enable=YES option in the main config file allows anonymous uploads.
via the command line

26. What command can you use to monitor and troubleshoot network connections?
createrepo
The tcpdump command is used to monitor network connections on different interfaces.
Version 2 is the latest and most secure version of SSH.
used for kickstart and/or network installs

27. What command can you use to view the current ACL on a file?
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.
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.
getfacl

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

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29. What benefit does a web proxy provide to your network?
A web proxy can provide multiple benefits - including security - web page caching for faster load times - and load balancing.
Typing the mail or mutt command allows you to read mail from the command line.
No. Red Hat Enterprise Linux 6 uses a different key to sign its packages.
Enforcing during installation

30. What port does NFS use by default?
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.
Upstart. The Upstart utility is now used in the boot process for Red Hat Enterprise Linux 6.
By default - the rndc utility listens on port 953.
The NFS service uses TCP port 2049 by default.

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

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32. What command-line program can you use to check your mail?
Dovecot supports the POP3 - POP3S - IMAP - and IMAPS protocols.
Typing the mail or mutt command allows you to read mail from the command line.
schedule one-time-only jobs
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.

33. What command can you use to view NFS statistics?
The nfsstat command can be used to view NFS statistics.
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 four types of DNS servers are master - slave - caching-only - and forwarding.
have the same effect

34. What is PAM used for?
Using the chcon command - you can change the context of a file to work with Apache.
The four types of DNS servers are master - slave - caching-only - and forwarding.
have the same effect
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.

35. What command is used to create a user for Samba?
The smbpasswd command is used to create Samba users.
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.
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 testparm command allows you to check for syntax errors in the /etc/samba/smb.conf file.

36. What command is used to change the mail server from Sendmail to Postfix (useful only if you have both installed)?
alternatives --config mta
By default - Squid runs on port 3128.
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
defining a %pre section although it is rarely used

37. Which log file is used to keep track of policy violations?
halts the system
The gateway is incorrectly set - and the subnet of the host you are trying to reach is inaccessible.
The /var/log/audit/audit.log file contains all policy violations.
kickstart installations to work

38. A service needs to have _______________ to be able to use it.
support for TCP Wrappers
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.
run on any port you'd like (provided that port is available)
Use the ps command to view processes and their CPU usage.

39. What command can you use to query information from the kernel about RAID arrays?
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.
cat /proc/mdstat
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.
The /var/lib/nfs/etab file is used to keep track of currently exported resources.

40. How can virtual hosts be used?
After you connect to a hypervisor - you can use virsh list —all to list all virtual guests.
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.
chkconfig—list
support TCP Wrappers

41. What command can you use to test connectivity to another host?
The ping command can be used to verify connectivity to another host.
via the command line
used for kickstart and/or network installs
You can use the sudo command to run a command with elevated privileges provided you have the rights in the /etc/sudoers file.

42. Which remote management service is installed by default?Can you name the port that it uses?
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.
SELinux Booleans provide restrictions to different aspects of a service.
The /etc/fstab file.
By combining a TFTP server - PXE boot - and DHCP server - you can fully automate the kickstart installation process.

43. What is the /var/lib/nfs/etab file used for?
The tcpdump command is used to monitor network connections on different interfaces.
run on any port you'd like (provided that port is available)
The /var/lib/nfs/etab file is used to keep track of currently exported resources.
The smbpasswd command is used to create Samba users.

44. What command can you use to change the context of files?
The /etc/exports file needs to contain any directory that you want to export - including which options you'd like to use as well.
chcon
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 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

45. What two ports should be opened on the firewall for the FTP server to function properly?
The user_list file can be used to limit which users have access to the FTP server.
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.
chcon
You must open TCP ports 20 and 21 for the FTP server to function properly.

46. What is the difference between an A record and a PTR record?
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.
An A record translates translated hostnames to IP addresses - and a PTR record works the other way around.
Uncomment the following line in the /etc/rsyslog.conf file: #$ModLoad imudp.so #$UDPServerRun 514
enabled by default

47. What two commands are used for package management?
The yum and rpm commands are used for package management.
Use the ps command to view processes and their CPU usage.
chkconfig xinetd --list
The three utilities are: route - ping - and nslookup.

48. Do you need to write changes to the disk when using the parted command? What about fdisk?
Using the host option in the dhcpd.conf file allows you to reserve a client IP address based on its MAC address.
Use the route command with the add option to create a static route.
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.
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.

49. What command would you use to create a group - to add the user George to the group?
The format of the /etc/shadow file is <username>:<encrypted password>:<last passwd change>:<min>:<max>:<warn>:<inactive>:<expires>:<not used>.
Use the groupadd command to create a group. You can then add user George with the following: usermod -G <group name> George
chkconfig xinetd --list
Use the route command with the add option to create a static route.

50. What command and options can you use to update the time?
Use the yum groupinstall command to install multiple packages in a single group at once.
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.
After the ntpd service is stopped - you can use the ntpdate <server> command to update/sync the time.
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.