kernel
The kernel is in essence the central nervous system of Linux. It is what is used to access the hardware. Different pars of the kernel interact with NICs, SCSI controllers, sound cards, etc. Without the kernel you would just have a very heavy paperweight.
In order to modify or install a new kernel take the following steps.
1.) Make certain the kernel source code and supporting packages are installed on your system.
2.) Configure the modules you would like to use by looking in /lib/modules/version/kernel (the version is the version number of the kernel that is on your system.) and then use the modprobe to manually enter the modules you want.
3.) Use a string of make commands to compile your new kernel.
To maintain your Linux kernel modules you can use the modinfo command to learn about each of the modules that are currently installed, the rmmod command to remove a module, and the insmod command to install a new module into a running kernel.
Backups
For the command line utility that we are using in Pandora. I would do a backup of all the work that the students are doing. This way if there is a memory loss on the server the students do not lose all of there work.
By backing up once a month it would protect the students work, and if there is a loss then there would not be as much to catch up on.
Linux components are very reliable so I would use the dump command to do my backups, and then the restore command if a restore is neccessary.
I would have a backup server that is a clone of the first. This way there is a large enough space to hold several months worth of backups. If there is a problem with a backup there will be more on the server to take its place.
Friday, May 1, 2009
Sunday, April 26, 2009
Chapter 12 Case Project
1.) For the smaller office of the firm I would recommend using a /etc/hosts file versus a DNS server. Because of the large spread out nature of the firm I would use the DNS overall because it would be easier to maintain that one server instead of having to maintain the /etc/hosts files in each of the buildings. It would also be cheaper this way because the DNS server would be centrally located.
2.) In order to properly maintain static IP addresses you have to have a skilled network administrator that is able to account for variable change, so I would recommend using DHCP servers in each of the offices. This would eliminate most of the chances for human error with the IP addressing, and ease some of the burdon off of the administrator. While there is still work in maintaining the DHCP servers it is negligible compared to the cost of having to track down a faulty IP address.
3.) I would go with the Konica Minolta bizhub c550 for the firms printing needs. It offers a wide range of features, has superior quality printing, and comes from a trusted name in Minolta. This model is designed for business, and has an easy to use touch screen. It is perfectly rated to be used on Linux operating systems, and you are able to get support directly from the Konica Minolta site. Running a search engine on the web also brings up many support sites with places to buy repair parts and toner.
2.) In order to properly maintain static IP addresses you have to have a skilled network administrator that is able to account for variable change, so I would recommend using DHCP servers in each of the offices. This would eliminate most of the chances for human error with the IP addressing, and ease some of the burdon off of the administrator. While there is still work in maintaining the DHCP servers it is negligible compared to the cost of having to track down a faulty IP address.
3.) I would go with the Konica Minolta bizhub c550 for the firms printing needs. It offers a wide range of features, has superior quality printing, and comes from a trusted name in Minolta. This model is designed for business, and has an easy to use touch screen. It is perfectly rated to be used on Linux operating systems, and you are able to get support directly from the Konica Minolta site. Running a search engine on the web also brings up many support sites with places to buy repair parts and toner.
Saturday, April 18, 2009
Password Proposal
From the desk of Christopher M. Edwards
Memorandum 11.2
Password Security
Members of the board:
As you are all aware, last week we had a major security breach into our company. After looking into it further we have discovered that the breach was caused by an employee that had used her daughter's birth date as her password. In Memorandum 11.1 I had warned against using such passwords because they are among the easiest to hack. Anyone that has access to personal information can use methods of deduction to decipher common passwords such as birth dates, hobbies, or anniversaries. It is in my professional opinion that we need to take further steps to prevent future breaches into our company.
By changing certain features that are stored in the password protection files we can make it to where passwords have to meet certain parameters in order to be used. If these changes are implemented we can require passwords to be at least certain length, that they are not words found in a dictionary, and that they have a variety of lowercase, uppercase, symbols and numbers.
Other features can be altered to change how long the password is good for. This makes sure that an employee is changing their password often enough that if someone does hack into the system using a known password, that password is only good for so long before it must be changed again. We can also make it to where you can not use the same password within a certain time period. If you have used the password within a given number of changes you will not be able to use it again until a sufficient period of time has elapsed.
If we make these changes it will go a long way towards maintaining our companies internal and external security, as well as giving piece of mind to everyone that our information is secure.
Thank you,
Christopher M. Edwards
Network Manager
Memorandum 11.2
Password Security
Members of the board:
As you are all aware, last week we had a major security breach into our company. After looking into it further we have discovered that the breach was caused by an employee that had used her daughter's birth date as her password. In Memorandum 11.1 I had warned against using such passwords because they are among the easiest to hack. Anyone that has access to personal information can use methods of deduction to decipher common passwords such as birth dates, hobbies, or anniversaries. It is in my professional opinion that we need to take further steps to prevent future breaches into our company.
By changing certain features that are stored in the password protection files we can make it to where passwords have to meet certain parameters in order to be used. If these changes are implemented we can require passwords to be at least certain length, that they are not words found in a dictionary, and that they have a variety of lowercase, uppercase, symbols and numbers.
Other features can be altered to change how long the password is good for. This makes sure that an employee is changing their password often enough that if someone does hack into the system using a known password, that password is only good for so long before it must be changed again. We can also make it to where you can not use the same password within a certain time period. If you have used the password within a given number of changes you will not be able to use it again until a sufficient period of time has elapsed.
If we make these changes it will go a long way towards maintaining our companies internal and external security, as well as giving piece of mind to everyone that our information is secure.
Thank you,
Christopher M. Edwards
Network Manager
Saturday, April 11, 2009
Chapter 10 Review Questions
1.) Name the two widely used software package formats for Linux, with the file system extensions used for each type and the command-line utility use to manage each.
The Red Hat Package Manger uses the .tgz file extension and the rpm command-line utility. The Debian package format uses the .deb file extension and the dpkg command-line utility.
2.) Within the system-config-packages utility, selecting details and checking a package name:
Marks the package as one that will be installed after the Update button is selected after other categories of packages have also been reviewed for possible changes.
3.) Which option of the rpm command is used to verify the cryptographic signature so you know for certain the person or organization that created a given rpm file?
--checksig or -K
4.) If you know the name of a package, you can see a list of all the files contained in that package using this command:
rpm -ql packagename
5.) If you have an rpm-format file stored on your system, and then you use the rpm command to install that software package, the rpm file will no longer be on your system. True or False?
False
6.) When querying an installed package using the -q option, you use ______; when installing an rpm file using the -U option you use ______:
The name of the package alone; the complete file name with all version numbers and file extensions.
7.) The command rpm -q packagename does the following:
Determines whether packagename is installed on the system.
8.) The volume label for a file system is:
Stored in /etc/fstab
9.) Defragmentation, the process of collecting all parts of a file into one contiguous part of a hard disk:
Is not needed in Linux because of the way ext2, ext3, and other Linux file systems arrange files.
10.) The Linux kernel is able to support multiple file system types because it uses:
A virtual file system that separates standard disk operations from the drivers that perform those operations.
11.) Which piece of information is not provided in the output when the mount command is entered with no parameters or options?
The size of each mounted file system
12.) Which of the following lists contains only commands used to learn about the status of file systems?
df, du, fsck, tune2fs, mount
13.) The ______ command is used to display the attributes assigned to a file or directory?
lsattr
14. Name two attributes that are currently supported by the ext3 file system and tow attributes that are not yet supported or are used only for developers at this time.
A, and a are currently supported. X and Z are used by developers.
15.) The Linux command used to format a Linux ext3 hard disk partition is:
mke2fs
16.) Disk quotas let you manage how much disk space a user consumes, but they must be first enabled:
On the file system where you want the quota to apply (in /etc/fstab)
17.) A mounted file system is defines as one that:
Has been included as part of the Linux directory structure.
18.) The fdisk utility is used to:
establish partitions of the correct type to hold a Linux file system.
19.) The df utility provides information about which one of the following?
File system capacity, device name, and percentage used status for each mounted file system.
20.) Describe the effect of the defaults option in a configuration line of the /etc/fstab file.
Defaults includes the following options in the configuration automatically: rw, suid, dev, exec, auto, nouser, and async.
21.) Describe the main advantage of having swap space located on a hard disk separate from the Linux data partitions.
It allows both hard drives to work at the same time and increases system performance.
22.) If you attempt to unmount a mounted file system and receive an error message, the most likely cause is:
One or more users are working in the file system.
23.) The autofs service is used to:
Permit users to access file systems that are not mounted by automatically mounting them when the user enters a configured directory (mount point).
24.) Virtual memory space to be used by the kernel must be located on a single separate partition, which can be located on the same hard disk or a different hard disk from the root file system. True of False?
False
25.) Which command is used to establish a quota for a user when disk space quotas have been enabled for a file system?
edquota
The Red Hat Package Manger uses the .tgz file extension and the rpm command-line utility. The Debian package format uses the .deb file extension and the dpkg command-line utility.
2.) Within the system-config-packages utility, selecting details and checking a package name:
Marks the package as one that will be installed after the Update button is selected after other categories of packages have also been reviewed for possible changes.
3.) Which option of the rpm command is used to verify the cryptographic signature so you know for certain the person or organization that created a given rpm file?
--checksig or -K
4.) If you know the name of a package, you can see a list of all the files contained in that package using this command:
rpm -ql packagename
5.) If you have an rpm-format file stored on your system, and then you use the rpm command to install that software package, the rpm file will no longer be on your system. True or False?
False
6.) When querying an installed package using the -q option, you use ______; when installing an rpm file using the -U option you use ______:
The name of the package alone; the complete file name with all version numbers and file extensions.
7.) The command rpm -q packagename does the following:
Determines whether packagename is installed on the system.
8.) The volume label for a file system is:
Stored in /etc/fstab
9.) Defragmentation, the process of collecting all parts of a file into one contiguous part of a hard disk:
Is not needed in Linux because of the way ext2, ext3, and other Linux file systems arrange files.
10.) The Linux kernel is able to support multiple file system types because it uses:
A virtual file system that separates standard disk operations from the drivers that perform those operations.
11.) Which piece of information is not provided in the output when the mount command is entered with no parameters or options?
The size of each mounted file system
12.) Which of the following lists contains only commands used to learn about the status of file systems?
df, du, fsck, tune2fs, mount
13.) The ______ command is used to display the attributes assigned to a file or directory?
lsattr
14. Name two attributes that are currently supported by the ext3 file system and tow attributes that are not yet supported or are used only for developers at this time.
A, and a are currently supported. X and Z are used by developers.
15.) The Linux command used to format a Linux ext3 hard disk partition is:
mke2fs
16.) Disk quotas let you manage how much disk space a user consumes, but they must be first enabled:
On the file system where you want the quota to apply (in /etc/fstab)
17.) A mounted file system is defines as one that:
Has been included as part of the Linux directory structure.
18.) The fdisk utility is used to:
establish partitions of the correct type to hold a Linux file system.
19.) The df utility provides information about which one of the following?
File system capacity, device name, and percentage used status for each mounted file system.
20.) Describe the effect of the defaults option in a configuration line of the /etc/fstab file.
Defaults includes the following options in the configuration automatically: rw, suid, dev, exec, auto, nouser, and async.
21.) Describe the main advantage of having swap space located on a hard disk separate from the Linux data partitions.
It allows both hard drives to work at the same time and increases system performance.
22.) If you attempt to unmount a mounted file system and receive an error message, the most likely cause is:
One or more users are working in the file system.
23.) The autofs service is used to:
Permit users to access file systems that are not mounted by automatically mounting them when the user enters a configured directory (mount point).
24.) Virtual memory space to be used by the kernel must be located on a single separate partition, which can be located on the same hard disk or a different hard disk from the root file system. True of False?
False
25.) Which command is used to establish a quota for a user when disk space quotas have been enabled for a file system?
edquota
Friday, April 3, 2009
Chapter 9 Review Questions
1.) Which of the following occurs first when a computer is booted?
The CPU starts executing commands found in the BIOS.
2.) On new computers, the BIOS can typically boot from which of the following devices?
Hard disks, CD-ROM drives, removable disks, a network connection, or USB devices.
3.) When using LILO rather than GRUB, you must do which of the following after making a configuration change in order for the change to be effective the next time you boot Linux?
Run the lilo command as root.
4.) Assuming a standard configuration, the BIOS looks first in which of the following locations on a hard disk when trying to find a boot loader or operating system?
The boot record of the active partition on the first IDE hard disk.
5.) In order to use chained boot loaders, you must be certain that:
The first boot loader can be found by the BIOS, and each operating system can be reached via one of the chained boot loaders.
6.) The Linux kernel is a file having a name that starts with _____ and typically stored in the ______ subdirectory.
vmlinuz, /boot
7.) Which feature is part of GRUB but not LILO?
Including non-Linux operating systems in the list of bootable devices.
8.) Describe the output of the uname command.
It just says Linux, but if you add different designators to the command you can change the output.
9.) The GRUB boot manager can be reconfigured directly as you boot your system, but is also controlled by this configuration file:
/boot/grub/grub.conf
10.) Which of the following statements about boot parameters is accurate?
They are passed to the Linux kernel by the boot loader.
11.) The scripts in /etc/rc.d/init.d are provided by:
The software package that installs the service that the script controls.
12.) Explain the difference between the configuration data stored in files within the /etc/sysconfig directory and service-specific configuration data stored in other subdirectories of /etc.
You can edit the /etc/sysconfig files directly, where as if you use the service-specific configuration files the alterations you make there make the changes themselves.
13.) The ______ utility displays kernel hardware configuration messages from the system boot process.
dmesg
14.) The init program relies on the following configuration file:
/etc/inittab
15.) Name the two run levels normally used to run a Linux-based computer, and describe the difference between the two run levels.
Level 3 which has a non-graphical login, and level 5 which has a graphical login.
16.) The files in /etc/rc.d/init.d can be used to:
Stop and restart most standard services in Linux.
17.) Name three commands that can be used to begin a graceful shutdown of Linux.
reboot, halt, and shutdown
18.) A boot loader can be configured to boot multiple Linux kernel that use the same partition as their root file system. True or False?
False
19.) The timeout= parameter in a GRUB configuration and the delay=parameter in a LILO configuration both refer to:
How long the boot loader waits for user input before booting the default operating system.
20.) The service command is used to:
View or change the current status of a service via a script in /etc/rc.d/init.d
21.) The chkconfig command is used to:
Change the boot-up status of a service that is controlled via a script located in /etc/rc.d/init.d
22.) Name the graphical configuration utility provided with Red Hat Linux and Fedora that can be used in place of the command-line utilities service and chkconfig.
The Service Configuration utility.
23.) If a journaling file system prevents partially written information from causing a corrupted file system in Linux, why is it still important to use graceful shutdown techniques rather than just turning off the system power?
Because you can still lose important data that has not yet been written to the disk. If you do a graceful shutdown it gives the system a chance to write the data.
24.) Which command is typically executed when the Ctrl+Alt+Del key combination is pressed, and where is that command configured?
It is a shutdown command that automatically restarts the system. It is configured in the /etc/inittab file.
25.) What is the command you use to cause the init program to reread its configuration file after you have made changes to it?
telinit
The CPU starts executing commands found in the BIOS.
2.) On new computers, the BIOS can typically boot from which of the following devices?
Hard disks, CD-ROM drives, removable disks, a network connection, or USB devices.
3.) When using LILO rather than GRUB, you must do which of the following after making a configuration change in order for the change to be effective the next time you boot Linux?
Run the lilo command as root.
4.) Assuming a standard configuration, the BIOS looks first in which of the following locations on a hard disk when trying to find a boot loader or operating system?
The boot record of the active partition on the first IDE hard disk.
5.) In order to use chained boot loaders, you must be certain that:
The first boot loader can be found by the BIOS, and each operating system can be reached via one of the chained boot loaders.
6.) The Linux kernel is a file having a name that starts with _____ and typically stored in the ______ subdirectory.
vmlinuz, /boot
7.) Which feature is part of GRUB but not LILO?
Including non-Linux operating systems in the list of bootable devices.
8.) Describe the output of the uname command.
It just says Linux, but if you add different designators to the command you can change the output.
9.) The GRUB boot manager can be reconfigured directly as you boot your system, but is also controlled by this configuration file:
/boot/grub/grub.conf
10.) Which of the following statements about boot parameters is accurate?
They are passed to the Linux kernel by the boot loader.
11.) The scripts in /etc/rc.d/init.d are provided by:
The software package that installs the service that the script controls.
12.) Explain the difference between the configuration data stored in files within the /etc/sysconfig directory and service-specific configuration data stored in other subdirectories of /etc.
You can edit the /etc/sysconfig files directly, where as if you use the service-specific configuration files the alterations you make there make the changes themselves.
13.) The ______ utility displays kernel hardware configuration messages from the system boot process.
dmesg
14.) The init program relies on the following configuration file:
/etc/inittab
15.) Name the two run levels normally used to run a Linux-based computer, and describe the difference between the two run levels.
Level 3 which has a non-graphical login, and level 5 which has a graphical login.
16.) The files in /etc/rc.d/init.d can be used to:
Stop and restart most standard services in Linux.
17.) Name three commands that can be used to begin a graceful shutdown of Linux.
reboot, halt, and shutdown
18.) A boot loader can be configured to boot multiple Linux kernel that use the same partition as their root file system. True or False?
False
19.) The timeout= parameter in a GRUB configuration and the delay=parameter in a LILO configuration both refer to:
How long the boot loader waits for user input before booting the default operating system.
20.) The service command is used to:
View or change the current status of a service via a script in /etc/rc.d/init.d
21.) The chkconfig command is used to:
Change the boot-up status of a service that is controlled via a script located in /etc/rc.d/init.d
22.) Name the graphical configuration utility provided with Red Hat Linux and Fedora that can be used in place of the command-line utilities service and chkconfig.
The Service Configuration utility.
23.) If a journaling file system prevents partially written information from causing a corrupted file system in Linux, why is it still important to use graceful shutdown techniques rather than just turning off the system power?
Because you can still lose important data that has not yet been written to the disk. If you do a graceful shutdown it gives the system a chance to write the data.
24.) Which command is typically executed when the Ctrl+Alt+Del key combination is pressed, and where is that command configured?
It is a shutdown command that automatically restarts the system. It is configured in the /etc/inittab file.
25.) What is the command you use to cause the init program to reread its configuration file after you have made changes to it?
telinit
Sunday, March 29, 2009
OLPC
One Laptop Per Child is a brilliant idea that has the goal of bringing laptops to the underprivelaged children of the world. Announced to the public in January 2005 OLPC rolled out 1,000,000 laptops to several different countries during their initial release. While there were a number of different concepts preceding OLPC, it is the main program that has survived the startup period.
A major contributor to the success of OLPC is that companies such as Red Hat, and Microsoft are both contributing operating systems for the laptops. To me this is a step in the right direction for major companies. There are also companies that are working on making cheap but functional laptops such as the XO-2, and the CM1. If more companies followed these examples I have no doubt that every child in the world could have a working laptop and be able to get access to the educational material that is now available on the World Wide Web.
OLPC is by far not the only program of this nature that is out in the world today. Another major program is called Give 1 Get 1. This program allows you either buy a single unit for $199 and have it sent to a underprivelaged child somewhere in the world, or you can buy two units for $399 and keep the second unit for yourself. OLPC and Give 1 Get 1 while not 100% successful yet are both heading in the right direction.
OLPC is designed to help underprivelaged children across the globe get their own laptops. There are countires on every inhabited continent that participate in the program. As this program grows more and more children are able to get the education they have otherwise been denied. This is a very good thing in my book. With the way the world is changing getting an education is more and more important.
Unfortunately there is also a negative with the program. The "cheap" laptops are not widely available, and you can not go out to the store and just buy one. This can cause major problems with children being at risk for theft, as well as people taking advantage of the lack of availability by auctioning off the laptops on places like e-bay.
A major contributor to the success of OLPC is that companies such as Red Hat, and Microsoft are both contributing operating systems for the laptops. To me this is a step in the right direction for major companies. There are also companies that are working on making cheap but functional laptops such as the XO-2, and the CM1. If more companies followed these examples I have no doubt that every child in the world could have a working laptop and be able to get access to the educational material that is now available on the World Wide Web.
OLPC is by far not the only program of this nature that is out in the world today. Another major program is called Give 1 Get 1. This program allows you either buy a single unit for $199 and have it sent to a underprivelaged child somewhere in the world, or you can buy two units for $399 and keep the second unit for yourself. OLPC and Give 1 Get 1 while not 100% successful yet are both heading in the right direction.
OLPC is designed to help underprivelaged children across the globe get their own laptops. There are countires on every inhabited continent that participate in the program. As this program grows more and more children are able to get the education they have otherwise been denied. This is a very good thing in my book. With the way the world is changing getting an education is more and more important.
Unfortunately there is also a negative with the program. The "cheap" laptops are not widely available, and you can not go out to the store and just buy one. This can cause major problems with children being at risk for theft, as well as people taking advantage of the lack of availability by auctioning off the laptops on places like e-bay.
Monday, March 9, 2009
Chapter 7 Review Questions
1.) Name three types of remote connectivity supported by Linux and explain why one is better than the other two.
SSH, the r-utilities, and Telnet. SSH is a more secure protocol.
2.) One advantage of Telnet is that:
It can be used on many different platforms, including Linux and Windows.
3.) Name three utilities that are part of the r-utilities and explain what each does.
There is rsh for executing a command on a remote host without actually logging on to the system, rcp which allows you to copy files between two hosts, and rlogin which lets you login to a remote system in a similar way to Telnet.
4.) The rcp program is able to copy files between:
Any two computers that are configure to use the r-utilities programs.
5.) Name the three types of authentication that SSH can use to connect to a remote system. Which is preferred as the most secure?
You can use the r-utilities, using passwords, or public key encryption. The public key encryption is the most secure.
6.) Which utility is used to prepare a set of keys needed to use public key encryption within SSH?
ssh-keygen
7.) Why might you need to use the -l option with the ssh command?
It tells you that you are wanting to access the user account that immediately follows the option.
8.) If you use the ssh command without first creating and storing a key pair on the remote host:
You are prompted for a password to aid authentication.
9.) If you have installed and configured r-utilities, then including a host and user name in your .rhosts file allows a person using the rcp command on another host to:
Copy files to or from your home directory without entering a password.
10.) SSH is commonly used in place of Telnet because:
SSH protocols use a more robust encryption algorithm than that used by Telnet.
11.) When using Telnet you might refer to VT100 because it is:
The most commonly used terminal emulation standard.
12.) Telnet is considered dangerous because:
It transmits data--including passwords--without encrypting them, so anyone on the network can see them by using special software.
13.) When using the wget command, you should include the http:// designation to download a Web page so that:
The program knows which protocol to use when accessing the server.
14.) Suppose you want to mirror a Web site to your local computer in order to study the information it contains. You intend to update the mirror once each month to view changes in the Web pages on the site. You are concerned that the Web site administrator will block access if he realizes you are mirroring the entire site instead of using a regular browser to access it. In order to reduce the chance that the wget program creates suspicion, you can:
Use the --random-wait option with wget.
15.) The rsync program is best suited for:
Synchronizing collections of files such as software development files.
16.) On a publicly available anonymous FTP server, the first level subdirectory that you should to to when locating files to download is virtually always:
/pub
17.) A graphical FTP client can be more convenient than a text-mode FTP client such as ncftp because:
The graphical program lets you see lists of files locally and remotely and drag and drop multiple files between systems.
18.) The ncftp package includes a utility that is similar in functionality to wget. This utility is called:
ncftpget
19.) If an IP address is not assigned explicitly when networking is configured, one must be obtained automatically from a server on the network using ________.
DHCP
20.) The process of resolving a domain name:
Determines the IP address associated with that domain name by contacting a DNS server.
21.) ping is used to test networking connections by:
Trying to contact systems that are progressively further from your host to see if any networking problems occur.
22.) traceroute is a useful troubleshooting tool because:
It reports each router that a packet passes through to a remote computer, along with the time needed to reach that router.
23.) If you cannot ping a host on your local network using that system's IP address, you probably wouldn't bother checking:
Whether you could ping that system using its domain name or host name.
24.) Which of the following is not included in the output of the traceroute command?
The size of the test packet sent by traceroute.
25.) A DHCP server can provide what information to a host on the network in response to a DHCP client request?
An IP address, a network mask, a gateway address, a DNS server address, and a host name, among other things.
SSH, the r-utilities, and Telnet. SSH is a more secure protocol.
2.) One advantage of Telnet is that:
It can be used on many different platforms, including Linux and Windows.
3.) Name three utilities that are part of the r-utilities and explain what each does.
There is rsh for executing a command on a remote host without actually logging on to the system, rcp which allows you to copy files between two hosts, and rlogin which lets you login to a remote system in a similar way to Telnet.
4.) The rcp program is able to copy files between:
Any two computers that are configure to use the r-utilities programs.
5.) Name the three types of authentication that SSH can use to connect to a remote system. Which is preferred as the most secure?
You can use the r-utilities, using passwords, or public key encryption. The public key encryption is the most secure.
6.) Which utility is used to prepare a set of keys needed to use public key encryption within SSH?
ssh-keygen
7.) Why might you need to use the -l option with the ssh command?
It tells you that you are wanting to access the user account that immediately follows the option.
8.) If you use the ssh command without first creating and storing a key pair on the remote host:
You are prompted for a password to aid authentication.
9.) If you have installed and configured r-utilities, then including a host and user name in your .rhosts file allows a person using the rcp command on another host to:
Copy files to or from your home directory without entering a password.
10.) SSH is commonly used in place of Telnet because:
SSH protocols use a more robust encryption algorithm than that used by Telnet.
11.) When using Telnet you might refer to VT100 because it is:
The most commonly used terminal emulation standard.
12.) Telnet is considered dangerous because:
It transmits data--including passwords--without encrypting them, so anyone on the network can see them by using special software.
13.) When using the wget command, you should include the http:// designation to download a Web page so that:
The program knows which protocol to use when accessing the server.
14.) Suppose you want to mirror a Web site to your local computer in order to study the information it contains. You intend to update the mirror once each month to view changes in the Web pages on the site. You are concerned that the Web site administrator will block access if he realizes you are mirroring the entire site instead of using a regular browser to access it. In order to reduce the chance that the wget program creates suspicion, you can:
Use the --random-wait option with wget.
15.) The rsync program is best suited for:
Synchronizing collections of files such as software development files.
16.) On a publicly available anonymous FTP server, the first level subdirectory that you should to to when locating files to download is virtually always:
/pub
17.) A graphical FTP client can be more convenient than a text-mode FTP client such as ncftp because:
The graphical program lets you see lists of files locally and remotely and drag and drop multiple files between systems.
18.) The ncftp package includes a utility that is similar in functionality to wget. This utility is called:
ncftpget
19.) If an IP address is not assigned explicitly when networking is configured, one must be obtained automatically from a server on the network using ________.
DHCP
20.) The process of resolving a domain name:
Determines the IP address associated with that domain name by contacting a DNS server.
21.) ping is used to test networking connections by:
Trying to contact systems that are progressively further from your host to see if any networking problems occur.
22.) traceroute is a useful troubleshooting tool because:
It reports each router that a packet passes through to a remote computer, along with the time needed to reach that router.
23.) If you cannot ping a host on your local network using that system's IP address, you probably wouldn't bother checking:
Whether you could ping that system using its domain name or host name.
24.) Which of the following is not included in the output of the traceroute command?
The size of the test packet sent by traceroute.
25.) A DHCP server can provide what information to a host on the network in response to a DHCP client request?
An IP address, a network mask, a gateway address, a DNS server address, and a host name, among other things.
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