Linux - Chapter 12 - Network Configuration

What option can be used with SSH to enable tunneling of X Windows information?

-X

What option can be added to the netstat command in order to display network statistics?

-i

The configuration file(s) that is/are used to configure the BIND/DNS server:

/etc/named.conf

Which file holds the methods to be used and the order in which they will be applied for host name resolution?

/etc/nsswitch.conf

Which file stores the TCP/IP addresses of the DNS servers used to resolve host names if no DNS servers are specified within the network configuration file for the NIC?

/etc/resolv.conf

The SSHD daemon is configured by editing what configuration file?

/etc/ssh/sshd_config

Which file would you modify to permanently change the TCP/IP address of the first wired NIC on a Fedora 20 system?

/etc/sysconfig/network-scripts/ifcfg-eth0

Where are the log files for the Samba daemon located?

/var/log/samba

What range of ports is considered to be "well-known"?

0-1023

Which of the following port numbers is associated with telnet?

23

A Class A network uses how many bits for the network ID, and how many bits for the host ID?

24 bits for network ID 8 bits for host ID

What well-known TCP port is utilized by the SMTP service?

25

What is the subnet mask for a Class B IP address?

255.255.0.0

What is the subnet mask for a Class C IP address?

255.255.0.0

What two IP addresses below cannot be assigned to a host computer because they refer to all networks and all computers on all networks, respectively?

255.255.255.255 0.0.0.0

What is the Advanced Encryption Standard (AES) encryption algorithm's largest key length size?

256-bit

The number of bits needed to make an IPv4 and IPv6 IP address?

32 bits for an IPv4 128 bits for an IPv6

Each octet in an IP address represents a binary number consisting of how many bits/bytes?

8-bit

IPv6 IP address are delimited by what character?

:

What is VNC? How does it transfer graphics across the network?

A Virtual Network Computer (VNC) is a cross-platform technology that allows users to connect to a graphical desktop across a network. It transfers graphics across the network by using the special platform-independent protocol called Remote FrameBuffer (RFB) to transfer graphics, mouse movements, and keystrokes across the network.

Describe what a subnet mask is, and explain why it is used. The, detail how it is used to determine the network ID of an IP address.

A subnet mask is the 8-bit number used to determine the network and host portions of an IP address. It is used to divide an IP address into two parts that identify the host (computer), and the other identifies the (network) to which it belongs to. A subnet mask is a 32-bit number used to differentiate the network component of an IP address by dividing the IP address into a network address and host address. It does so with bit arithmetic whereby a network address is but multiplied by the subnet mask revealing the underlying subnetwork. They are used to design subnetworks, or subnets that connect local networks, by determining both the number and size of subnets where the size of a subnet is the number of hosts that can be addressed.

_____________________is a mathematical operation that compares two binary digits and gives a result of 1 or 0. If both binary digits being compared have a value of 1, the result is 1. If one digit is 0 and the other is 1, or if both digits are 0, the result is 0.

ANDing

Which of the following are stand-alone daemons? (choose all that apply)

Apache (httpd) DNS (named)

What are two means available to resolve a host name to the appropriate TCP/IP address? (choose two answers)

DNS /etc/hosts

SLIP is a newer technology that PPP

False

Stand-alone daemons are started on demand using inetd or xinetd.

False

An IPv6 address consists of 16-bit numbers in what numbering scheme?

Hexadecimal or Expanded numbering scheme

Discuss modems, ISDN, and DSL. What types of data transfer speeds are each of these capable of? How are they typically configured?

Modems (modulator-demodulator) devices between the digital data of a computer and the analog signal of a telephone line, transmits data at 56KB/s and they are configured by using the Modem Manager utility ISDN modem is otherwise known as an integrated services digital network it is a digital phone connection that can transmit data, voice, and video over a normal telephone line. It is configured to route IP over a Dial-on-Demand Routing (DDR) link, by the use of the switch software and not the MFG or the model. It transfers speeds up to 128KB/s. DSL modem is a digital subscriber line (DSL) modem is a device used to connect a computer or router to a telephone line which provides the digital subscriber line service for connection to the Internet, which is often called DSL broadband. Typically they are configured via webpage accessing by typing the IP address given in the router's manual into the browser's address bar. Runs on speeds of 100MB/s.

Which Windows program is often used to connect to a Linux server via SSH?

Putty

Describe the telnet and SSH utilities. What is the difference between them?

SSH is a network protocol used to remotely access and manage a device. The key difference between Telnet and SSH is that SSH uses encryption, which means that all data transmitted over a network is secure from eavesdropping. Like Telnet, a user accessing a remote device must have an SSH client installed.

What tool is designed as a secure remote access utility that encrypts information that passes across the network?

Secure Shell (SSH)

___________________ is the process in which a single large network is subdivided into several smaller network to control traffic flow and improve manageability.

Subnetting

What is the most commonly used LAN protocol?

TCP/IP

A route table is a list of TCP/IP networks that is stored in system memory

True

A subnet mask is used to differentiate the host portion from the network portion in a TCP/IP address.

True

Class D addresses are used for Multicasting

True

Passwords used by the PPP daemon are stored in two files: /etc/ppp/pap-secrets and /etc/ppp/chap-secrets

True

SSH encrypts all traffic that passes across the network, whereas telnet does not.

True

The ARCfour encryption algorithm uses variable-length keys up to 2048 bits in length

True

The line that configures the host name for the computer at boot time can be found in /etc/hostname.

True

How do you configure a NIC? What do you do if the NIC is not detected during installation?

You can configure a NIC by using the ifconfig (interface configuration) command can be used to assign a TCP/IP configuration to a NIC as well as view the configuration of all network interfaces in the computer. If the NIC is not detected during installation then we need to view the appropriate Linux drivers for the NIC that were not included in the installation media.

(CIDR) notation

a notation that is often used to represent an IP address and its subnet mask

Octet

a port of an IP address that represents eight binary bits

Internet Protocol (IP) address

a series of four 8-bit numbers that represent a computer on a network

Protocol

a set of rules of communication used between computers on a network

Route Table

a table of information used to indicate which networks are connected to network interfaces

host name

a user-friendly name assigned to a computer

Before a computer can use a router, with what configuration information must it be provided?

default gateway

The IP address of the network interface on the router to which you send packets is called _____________________________.

default gateway

You can view or set the host name for a Linux computer using the _________________ command.

hostname

What command can be used to assign a TCP/IP configuration to a NIC as well as view the current configuration of all network interfaces?

ifconfig

Which of the following utilities can be used to check TCP/IP configuration and test network connectivity? (choose all that apply)

ifconfig ping netstat -i

Which command would be used to activate the NIC aliased as eth0?

ifup eth0

What two daemons can be used to start and manage connections for smaller network daemons such as telnet and rlogin?

inetd xinetd

What two commands can be used to manipulate the routing table?

ip route route

The TCP/IP address of 127.0.0.1 is also referred to as the _________________.

loopback address

In order to enable IP routing on Linux at boot, what setting must be configured in /etc/sysctl.conf?

net.ipv4.ip_forward

To test DNS configuration by resolving a host name to an IP address, which command or commands can you use? (choose all that apply)

nslookup hostname dig hostname resolve hostname

What is the command that can be used to send a small TCP/IP packet to another IP address and wait for a response?

ping

The daemons associated with network services listen for network traffic associated with a particular _____________________.

port

A network ________________ breaks information down into packets that can be recognized by workstations, routers, and other devices on a network.

protocol

Which two commands can be used to modify the route table on a Linux computer? (choose two)

route ip

What devices are used to transfer information from one network to another?

routers

Which of the following are graphical remote administration technologies? (choose all that apply)

ssh-x VNC

Multicast

the TCP/IP communication destined for a certain group of computers

broadcast

the TCP/IP communication destined for all computers on a network

IP version 4 (IPv4)

the most common version of IP used on the Internet, it uses 32-bit addressing scheme organized into different classes

link local

the portion of an IPv6 address that refers to a unique computer, it is analogous to the host portion of an IPv4 address

How many DNS servers can be configured in the /etc/resolv.conf file?

three (3)

What command can be used to troubleshoot routing by displaying all routers between the current computer and a remote computer?

traceroute