Linux Always Special - 1

Linux Always Special:)

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Useful Protocol Abbreviations

    Some Useful Protocol Abbreviations

Protocol is the special set of rules that end points in a telecommunication connection use when they communicate. Protocols specify interactions between the communicating entities.

ARP        Address Resolution Protocol

AFP        AppleTalk Filing Protocol

ALP        Appliance Link Protocol

BGP       Border Gateway Protocol

BIND      Berkeley Internet Name Domain

BCP        Binary Control Protocol

BOP       Bit-Oriented Protocol

BOOTP  Bootstrap Protocol

CGI         Common Gateway Interface

DDP       Datagram Delivery Protocol

DHCP    Dynamic Host Configuration Protocol

DIP         Dialup Internet Protocol

DNS       Domain Name Server protocol

DRP        Distribution and Replication Protocol

ESMTP  Extended Simple Mail Transfer Protocol

ECP Encryption Control Protocol

EGP        Exterior Gateway Protocol

FCP        Fibre Channel Protocol

FTP         File Transfer Protocol

GTP        GPRS Tunnelling Protocol

GREP     Global Regular Expression Print

HTTPS   Secure HypterText Transfer Protocol

HTTP     Hypertext Transfer Protocol

IMAP     Interim Mail Access Protocol

IP            Internet Protocol

IIP           Internet Imaging Protocol

ICA         Independent Computing Architecture

IPP         Internet Printing Protocol

IGP         Interior Gateway Protocol

ICMP     Internet Control Message Protocol

IPv6       revised version of IP

ISCSI      Internet Small Computer Systems Interface

IGRP      Interior Gateway Routing Protocol

IDP         Internet Datagram Protocol

LAP        Link Access Procedure

LFTP       Leech File Transfer Protocol

LDAP     Lightweight Directory Access Protocol

L2F         Layer 2 Forwarding protocol, permits the tunneling of the link layer of higher layer protocols

L2TP       Layer 2 Tunneling Protocol, used for integrating multiprotocol dialup services into existing ISP POP

LAT         Local Area Transport protocol, designed to handle multiplexed terminal traffic to/from timesharing hosts

MARS    Multicast Address Resolution Server

MDLP    Mobile Data Link Protocol

MOP      Maintenance Operation Protocol, utility services such as uploading and downloading system software, remote testing and problem diagnosis

NTP        Network Time Protocol, time synchronization system for computer clocks through the Internet network

NNTP    Network News Transfer Protocol

NCP       NetWare Core Protocol

NFS        Sun Network File System, file sharing application for the Sun protocol suite.

OTP        Open Trade Protocol

OSPF     Open Shortest Path First, linkstate routing protocol used for routing IP

PPTP      PointtoPoint Tunneling Protocol, allows PPP to be channeled through an IP network

PPP        PointtoPoint Protocol, designed for simple links which transport packets between two peers.

POP3     Post Office Protocol version 3, permits workstations to dynamically access a maildrop on a server host

Ping         Packet Internet Groper

PAP        Printer Access Protocol, manages the virtual connection to printers and other servers

RIP         Routing Information Protocol, maintains a database of network hosts and exchange information about the topology of the network

RLOGIN                Remote Login, allows UNIX users of one machine to connect to other UNIX systems across the Internet and interact as if their terminals are directly connected to the machines

RLP         Radio Link Protocol

RPM      Red Hat Package Manager

RP           Routing Protocol, distributes routing information among DECnet hosts.

SSP         Serial Storage Protocol

SGD       Secure Global Desktop

SPF         Shortest Path First

SRP        Extreme Standby Router Protocol

SSH        Secure Shell

SLIP        Serial Line Internet Protocol

SSL         Secure Sockets Layer

SMB       Server Message Block, Microsoft presentation layer protocol providing file and print sharing functions for LAN Manager, Banyan VINES and other networking operating systems.

SMTP    Simple Mail Transfer Protocol, mail service modeled on the FTP file transfer service

SNMP   Simple Network Management Protocol, developed by the Internet community to allow diverse network objects to participate in a global network management architecture.

TCP        Transmission Control Protocol, provides a reliable stream delivery and virtual connection service to applications through the use of sequenced acknowledgement with retransmission of packets when necessary

TFTP      Trivial File Transfer Protocol, supports file writing and reading

TELNET Terminal emulation protocol

UDP       User Datagram Protocol, provides a simple but unreliable message service for transaction oriented services

ULP        Upper Layer Protocol

UDA       Universal Data Access

VRRP     Virtual Router Redundancy Protocol

VPN       Virtual Private Network

VCI          Virtual Channel Identifier.

VSFTPD Very Secure File Transfer Protocol Daemon

WDP      Wireless Datagram Protocol

WSP      Wireless Session Protocol

WAP      Wireless Application Protocol

WDOG Watchdog protocol, provides constant validation of active workstation connections and notifies the NetWare operating system when a connection may be terminated as a result of lengthy periods without communication

WTP      Wireless Transaction Protocol

XMPP    Extensible Messaging and Presence Protocol

YUM      Yellowdog Updater Modified

 

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Linux Basic Interview Questions - Part4

1. You have a directory called /home/ben/memos and want to move it to /home/bob/memos so you issue the command mv /home/ben/memos /home/bob. What is the results of this action?
 

Choose one:
a. The files contained in /home/ben/memos are moved to the directory /home/bob/memos/memos.
b. The files contained in /home/ben/memos are moved to the directory /home/bob/memos.
c. The files contained in /home/ben/memos are moved to the directory /home/bob/.
d. The command fails since a directory called memos already exists in the target directory.
Answer: a
When using the mv command to move a directory, if a directory of the same name exists then a subdirectory is created for the files to be moved.

2. Which of the following tasks is not necessary when creating a new user by editing the /etc/passwd file?
 

Choose one:
a. Create a link from the user's home directory to the shell the user will use.
b. Create the user's home directory
c. Use the passwd command to assign a password to the account.
d. Add the user to the specified group.
Answer: a
There is no need to link the user's home directory to the shell command. Rather, the specified shell must be present on your system.

3. You issue the following command useradd -m bobm But the user cannot logon. What is the problem?
 

Choose one:
a. You need to assign a password to bobm's account using the passwd command.
b. You need to create bobm's home directory and set the appropriate permissions.
c. You need to edit the /etc/passwd file and assign a shell for bobm's account.
d. The username must be at least five characters long.
Answer: a
The useradd command does not assign a password to newly created accounts. You will still need to use the passwd command to assign a password.

4. You wish to print the file vacations with 60 lines to a page. Which of the following commands will accomplish this?

Choose one:
a. pr -l60 vacations | lpr
b. pr -f vacations | lpr
c. pr -m vacations | lpr
d. pr -l vacations | lpr
Answer: a
The default page length when using pr is 66 lines. The -l option is used to specify a different length.

5. Which file defines all users on your system?
 

Choose one:
a. /etc/passwd
b. /etc/users
c. /etc/password
d. /etc/user.conf
Answer: a
The /etc/passwd file contains all the information on users who may log into your system. If a user account is not contained in this file, then the user cannot log in.

6. Which two commands can you use to delete directories?
 

A) rm
B) rm -rf
C) rmdir
D) rd
E) rd -rf
Answer(s): B, C - You can use rmdir or rm -rf to delete a directory. Answer a is incorrect, because the rm command without any specific flags will not delete a directory, it will only delete files. Answers d and e point to a non-existent command.

7. Which partitioning tool is available in all distributions?
 

A) Disk Druid
B) fdisk
C) Partition Magic
D) FAT32
E) System Commander
Answer(s): B - The fdisk partitioning tool is available in all Linux distributions. Answers a, c, and e all handle partitioning, but do not come with all distributions. Disk Druid is made by Red Hat and used in its distribution along with some derivatives. Partition Magic and System Commander are tools made by third-party companies. Answer d is not a tool, but a file system type. Specifically, FAT32 is the file system type used in Windows 98.

8. Which partitions might you create on the mail server's hard drive(s) other than the root, swap, and boot partitions?
 

[Choose all correct answers]
A) /var/spool
B) /tmp
C) /proc
D) /bin
E) /home

Answer(s): A, B, E - Separating /var/spool onto its own partition helps to ensure that if something goes wrong with the mail server or spool, the output cannot overrun the file system. Putting /tmp on its own partition prevents either software or user items in the /tmp directory from overrunning the file system. Placing /home off on its own is mostly useful for system re-installs or upgrades, allowing you to not have to wipe the /home hierarchy along with other areas. Answers c and d are not possible, as the /proc portion of the file system is virtual-held in RAM-not placed on the hard drives, and the /bin hierarchy is necessary for basic system functionality and, therefore, not one that you can place on a different partition.

9. When planning your backup strategy you need to consider how often you will perform a backup, how much time the backup takes and what media you will use. What other factor must you consider when planning your backup strategy? _________
what to backup
Choosing which files to backup is the first step in planning your backup strategy.

10. What utility can you use to automate rotation of logs?
 

Answer: logrotate
The logrotate command can be used to automate the rotation of various logs.

11. In order to display the last five commands you have entered using the history command, you would type ___________ .
Answer: history 5
The history command displays the commands you have previously entered. By passing it an argument of 5, only the last five commands will be displayed.

12. What command can you use to review boot messages?
 

Answer: dmesg
The dmesg command displays the system messages contained in the kernel ring buffer. By using this command immediately after booting your computer, you will see the boot messages.

13. What is the minimum number of partitions you need to install Linux?
 

Answer: 2
Linux can be installed on two partitions, one as / which will contain all files and a swap partition.

14. What is the name and path of the main system log?
 

Answer: /var/log/messages
By default, the main system log is /var/log/messages.

15. Of the following technologies, which is considered a client-side script?  

A) JavaScript
B) Java
C) ASP
D) C++
Answer: A - JavaScript is the only client-side script listed. Java and C++ are complete programming languages. Active Server Pages are parsed on the server with the results being sent to the client in HTML

By: Unknown On 12:58 PM

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Linux Basic Interview Questions - Part3

1. When you create a new partition, you need to designate its size by defining the starting and ending _____________.
 

Answer: cylinders
 

When creating a new partition you must first specify its starting cylinder. You can then either specify its size or the ending cylinder.

2. What key combination can you press to suspend a running job and place it in the background?
 

Answer: ctrl-z
 

Using ctrl-z will suspend a job and put it in the background.

3.The easiest, most basic form of backing up a file is to _____ it to another location.
 

Answer: copy
The easiest most basic form of backing up a file is to make a copy of that file to another location such as a floppy disk.

4. What type of server is used to remotely assign IP addresses to machines during the installation process?
A) SMB
B) NFS
C) DHCP
D) FT
E) HTTP
Answer: C 

You can use a DHCP server to assign IP addresses to individual machines during the installation process. Answers a, b, d, and e list legitimate Linux servers, but these servers do not provide IP addresses. The SMB, or Samba, tool is used for file and print sharing across multi-OS networks. An NFS server is for file sharing across Linux net-works. FTP is a file storage server that allows people to browse and retrieve information by logging in to it, and HTTP is for the Web.

5. Which password package should you install to ensure that the central password file couldn't be stolen easily?
A) PAM
B) tcp_wrappers
C) shadow
D) securepass
E) ssh
Answer:C 

The shadow password package moves the central password file to a more secure location. Answers a, b, and e all point to valid packages, but none of these places the password file in a more secure location. Answer d points to an invalid package.

6. When using useradd to create a new user account, which of the following tasks is not done automatically.
Choose one:
a. Assign a UID.
b. Assign a default shell.
c. Create the user's home directory.
d. Define the user's home directory.
 Answer: c
The useradd command will use the system default for the user's home directory. The home directory is not created, however, unless you use the -m option.

7. You want to enter a series of commands from the command-line. What would be the quickest way to do this?
Choose One
a. Press enter after entering each command and its arguments
b. Put them in a script and execute the script
c. Separate each command with a semi-colon (;) and press enter after the last command
d. Separate each command with a / and press enter after the last command
Answer: c
The semi-colon may be used to tell the shell that you are entering multiple commands that should be executed serially. If these were commands that you would frequently want to run, then a script might be more efficient. However, to run these commands only once, enter the commands directly at the command line.

8. You attempt to use shadow passwords but are unsuccessful. What characteristic of the /etc/passwd file may cause this?
Choose one:
a. The login command is missing.
b. The username is too long.
c. The password field is blank.
d. The password field is prefaced by an asterisk.
Answer: c
The password field must not be blank before converting to shadow passwords.

9. When you install a new application, documentation on that application is also usually installed. Where would you look for the documentation after installing an application called MyApp?
Choose one:
a. /usr/MyApp
b. /lib/doc/MyApp
c. /usr/doc/MyApp
d. In the same directory where the application is installed.
Answer: c
The default location for application documentation is in a directory named for the application in the /usr/doc directory.

10. What file would you edit in your home directory to change which window manager you want to use?
A) Xinit
B) .xinitrc
C) XF86Setup
D) xstart
E) xf86init
Answer: B 

The ~/.xinitrc file allows you to set which window man-ager you want to use when logging in to X from that account.
Answers a, d, and e are all invalid files. Answer c is the main X server configuration file.

11. What command allows you to set a processor-intensive job to use less CPU time?
A) ps
B) nice
C) chps
D) less
E) more
Answer: B 

The nice command is used to change a job's priority level, so that it runs slower or faster. Answers a, d, and e are valid commands but are not used to change process information. Answer c is an invalid command.

12. While logged on as a regular user, your boss calls up and wants you to create a new user account immediately. How can you do this without first having to close your work, log off and logon as root?
Choose one:
a. Issue the command rootlog.
b. Issue the command su and type exit when finished.
c. Issue the command su and type logoff when finished.
d. Issue the command logon root and type exit when finished.
Answer: b
You can use the su command to imitate any user including root. You will be prompted for the password for the root account. Once you have provided it you are logged in as root and can do any administrative duties.

13. There are seven fields in the /etc/passwd file. Which of the following lists all the fields in the correct order?
Choose one:
a. username, UID, GID, home directory, command, comment
b. username, UID, GID, comment, home directory, command
c. UID, username, GID, home directory, comment, command
d. username, UID, group name, GID, home directory, comment
 

Answer: b
The seven fields required for each line in the /etc/passwd file are username, UID, GID, comment, home directory, command. Each of these fields must be separated by a colon even if they are empty.

14. Which of the following commands will show a list of the files in your home directory including hidden files and the contents of all subdirectories?
Choose one:
a. ls -c home
b. ls -aR /home/username
c. ls -aF /home/username
d. ls -l /home/username
Answer: b
The ls command is used to display a listing of files. The -a option will cause hidden files to be displayed as well. The -R option causes ls to recurse down the directory tree. All of this starts at your home directory.

15 .In order to prevent a user from logging in, you can add a(n) ________at the beginning of the password field.  

Answer: asterick
If you add an asterick at the beginning of the password field in the /etc/passwd file, that user will not be able to log in.

By: Unknown On 11:01 AM

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