# 6.5.5 Practice Questions IP Networking

Which of the following is a valid IP address?
172. 16.1.26

2.2.2.2

Explanation

A valid IPv4 address consists of 4 8-bit (1 byte) numbers separated by periods. For example, 10.0.0.65. Because they are 8 bits long, these numbers are frequently called octets. Even though we typically express these numbers using decimal notation, it’s important to remember that these numbers are binary numbers. The lowest value one of these numbers can have is 00000000. The decimal equivalent for this number is simply 0. The highest value one these numbers can take is 11111111. The decimal equivalent of this number is 255. Therefore, in decimal notation, each octet must contain a number between 0 and 255 inclusively.

222.55.0.0
223.16.5.0
192.15.5.55

Explanation
The following are Class C addresses: 192.15.5.55, 222.55.0.0, and 223,16.5.0. The first octet of Class C addresses is in the range of 192 to 223. The first octet of Class A addresses range from 1-126. The first octet of Class B addresses range from 128-191.

Which of the following IP addresses belong to the Class A network 114.0.0.0? (Tip: Assume the network is indicated by the default Class A portion of the IP address.)
114.0.0.15
114.122.66.12
114.58.12.0

Explanation
With a Class A network, the first octet indicates the network address. All hosts on the network must have the same value in the first octet (114).

Which of the following IP addresses have a default subnet mask of 255.255.0.0?
168.16.5.1
129.0.0.1
191.168.2.15

Explanation
IP addresses are divided into classes. The most common of these are classes A, B, and C. Each address class has a different default subnet mask. To identify the class of an IP address, look at its first octet. Class A networks use a default subnet mask of 255.0.0.0 and have 9-126 as their first octet. Class B networks use a default subnet mask of 255.255.255.0 and have 192-223 as their first octet. In this question, the IP addresses that fall in the Class B IP address range are 191.168.2.15, 129.0.0.1, and 168.16.5.1.

Which of the following IP address ranges is reserved for Automatic Private IP Addressing?
169.254.0.1 – 169.254.255.254

Explanation
The Internet Assigned Numbers Authority (IANA) has reserved 169.254.0.1 through 169.254.255.254 for Automatic Private IP Addressing (APIPA). APIPA also sets the subnet mask on the network to 255.255.0.0.

You have a small home network that uses 192.168.1.0 with the default subnet mask for the network address. The default gateway address in 192.168.1.254, and the router is providing DHCP on the network. The Wrk2 computer has been assigned the IP address of 192. 168.1..55. Which of the following is considered the loopback for the Wrk2 computer?
127.0.0.1

Explanation

You want to use your Windows workstation to browse the web sites on the Internet. You use a broadband DSL connection to access the Internet. Which network protocol must be installed on your workstation to do this?
IP

Explanation
The IP is the protocol of the Internet. If you want to use the Internet, your computer must have the IP protocol installed and configured. The Serial Line Internet Protocol (SLIP) is a mostly obsolete encapsulated of the Internet Protocol designed to work over serial ports and modem connections. The Point-to-Point Protocol (PPP) is also commonly used with modem connections. IPX/SPX is the protocol suite used on legacy NetWare networks. NetBIOS is the term used to describe the combination of two protocols: NetBEUI and NetBIOS. NetBIOS was used in early Windows networks. Because NetBIOS is a non-routable protocol, it was often combined with TCP/IP or IPX/SPX to enable internetwork communications.

Which protocols are used on the Internet to transmit Web pages from Web servers to Web browsers running on client workstations?
HTTPS
HTTP

Explanation
The HyperText Transfer Protocol (HTTP) is used by Web servers and browsers to transmit Web pages over the internet. This is often confused with HTML or HyperText Markup Language, which is the markup language used to create Web content. XML is also a markup language. SMTP is used to route electronic mail through the internetwork. E-mail applications provide the interface to communicate with SMTP or mail servers. The Network News Transfer Protocol or NNTP is an Internet application protocol used primarily for reading and posting Usenet articles.

You want to allow your users to download files from a server running the IP protocol. You want to protect access to the files by requiring user authentication to access specific directories on the server. Which IP protocol should you implement to provide this capability?
FTP

Explanation
You should implement the File Transfer Protocol (FTP). It enables file transfers and supports user authentication. The Trivial File Transfer Protocol (TFTP) also enables file transfer, but does not support user authentication. The Simple Mail Transfer Protocol (SMTP) is used to transfer email message from email clients to email servers. The Lightweight Directory Access Protocol is used to access information about network resources stored in a directory server. The Secure Shell Protocol (SSH) is used to securely access the console prompt of a remote computer system. The Simple Network Management Protocol (SNMP) is used to remotely monitor and manage network devices and hosts.

What protocol is used to send e-mail messages from a mail client to a mail server?
SMTP

Explanation
SMTP sends e-mail from a mail client to a mail server. FTP provides a generic method of transferring files. SNMP is used in network management systems to monitor network-attached devices for conditions that warrant administrative attention. POP3 and IMAP are both e-mail; protocols used by mail clients to retrieve e-mail from a mail server; however they can’t be used to send mail from the client to the server. The Trivial File Transfer Protocol (TFTP) is used for network file transfers.

You want to implement name resolution on the Linux workstations in your company. Which protocol will you use to do this?
DNS

Explanation
You can use DNS name resolution for Linux workstations for Linux workstations (as well as for most other operating systems). NetBIOS name resolution (LMHOSTS files or WINS) is typically used on Windows-based networks. The Lmhosts file is a local text file that maps Internet Protocol (IP) addresses to NetBIOS names of remote servers with which you want to communicate over the TCP/IP protocol. A WINS server address is only needed if your have older Windows clients on multiple networks. Network Time Protocol (NTP) is a means of transmitting time signals over a computer network. Simple Mail Transfer Protocol (SMTP) is used to route electronic mail through the Internetwork. E-mail applicatons provide the interface to communicate with SMTP or mail servers.

Which IP protocol is used by Web browsers and Web servers to exchange files?
HTTP

Explanation
HTTP is used by Web browsers and Web servers to exchange files (such as Web pages) through the network.

HTML is a data format that is used to create hypertext documents that can be viewed from multiple platforms. SSL secures messages being transmitted on the network. SMTP is used to route electronic mail through an internetwork.

Which of the following protocol do e-mail clients use to download messages from a remote mail server?
POP3

Explanation
The POP3 protocol is part of the IP protocol suite and used to retrieve e-mail from a remote server to a local client over a network connection. SNMP is a protocol used to monitor network traffic. SMTP is an IP protocol used to send e-mail. FTP is used to transfer files.

You’ve just installed the DNS service on a Windows server. Which port must be opened in the server’s firewall to allow clients to access the service?
53

Explanation
The DNS service runs on port 53 by default. Port 110 is used by the POP3 protocol. Port 143 is used by the IMAP protocol. Port 123 is used by the NTP protocol.

Secure Shell (SSH)
22
Apple Filing Protocol (AFP)
548
HTTP over SSL (HTTPS)
443
Hypertext Transfer Protocol (HTTP)
80
Server Message Block (SMB/CIFS) directly over TCP
445
Service Location Protocol (SLP)
427
Internet Message Access Protocol (IMAP)
143
Explanation
The default ports match with the following protocols:

Port 22: Secure Shell (SSH)
Port 80: Hypertext Transfer Protocol (HTTP)
Port 443: HTTP over SSL (HTTPS)
Port 445: Server Message Block (SMB/CIFS) directly over TCP.
Port 143: Internet Message Access Protocol (IMAP)
Port 427: Service Location )SLP)
Port 548: Apple Filing Protocol