Chapter 6 Internet Protocol

What would an ARP destination MAC address appear as?

This would be a layer 2 broadcast, or FF:FF:FF:FF:FF:FF.

Name the protocol that uses both TCP ports 20 and 21.

FTP uses both TCP ports 20 and 21 for the data channel and the control channel, respectively.

You need to have a connection to run applications that are installed on only your desktop computer at your office. Which protocol will provide a GUI interface to your work computer? A. Telnet B. FTP C. RDP D. IMAP E. SMTP

C. Remote Desktop Protocol (RDP) allows you to connect to a remote computer and run programs, as Telnet does. However, the large advantage that RDP has over Telnet is that RDP allows you to have a GUI interface connection.

If you can ping by IP address but not by hostname, or FQDN, which of the following port numbers is related to the server process that is involved? A. 21 B. 23 C. 53 D. 69 E. 80

C. The problem is with DNS, which uses both TCP and UDP port 53.

What layer 4 protocol is used for a Telnet connection, and what is the default port number? A. IP, 6 B. TCP, 21 C. USP, 23 D. ICMP, 21 E. TCP, 23

E. Telnet uses TCP at the transport layer with a default port number of 23.

What could cause a server that you can ping not to provide the particular TCP/IP service, such as FTP, HTTP, and so on, that you expect it to offer?

Quite simply, the service might not be running currently on that server. Another possibility might be that a firewall between the client and the server has blocked the protocol in question from passing.

Which of the following describe the DHCP discover message? (Choose two.) A. It uses FF:FF:FF:FF:FF:FF as a layer 2 broadcast B. It uses UDP as the transport layer protocol C. It uses TCP as the transport layer protocol D. It does not use a layer 2 destination address.

A, B. A client that sends out a DHCP discover message in order to receive an IP address sends out a broadcast at both layer 2 and layer 3. The layer 2 broadcast is all Fs in hex, or FF:FF:FF:FF:FF:FF. The layer 3 broadcast is 255.255.255.255, which means all networks and all hosts. DHCP is connectionless, which means it uses User Datagram Protocol (UDP) at the transport layer, also called the host-to-host layer.

Which of the following allows a server to distinguish among different simultaneous requests from the same host? A. They use different port numbers B. A NAT server changes the IP address for subsequent requests C. A server is unable to accept multiple simultaneous sessions from the same host. One session must end before another can begin D. The MAC address for each one is unique

A. Through the use of port numbers, TCP and UDP can establish multiple sessions between the same two hosts without creating any confusion. The sessions can be between the same or different applications, such as multiple web-browsing sessions or a web-browsing session and an FTP session.

Which of the following protocols can use TCP and UDP, permits authentication and secure polling of network devices, and allows for automated alerts and reports on network devices? A. DNS B. SNMP C. SMTP D. TCP

B. Simple Network Management Protocol is typically implemented using version 3, which allowed for a connection-oriented service, authentication and secure polling of network devices, and alerts and reports on network devices.

Which of the following TCP/IP protocols are used at the application layer of the OSI model? (Choose three.) A. IP B. TCP C. Telnet D. FTP E. TFTP

C, D, E. Telnet, File Transfer Protocol (FTP), and Trivial FTP (TFTP) are all application layer protocols. IP is a network layer protocol. Transmission Control Protocol (TCP) is a transport layer protocol.

What is the well-known port number for RDP?

RDP uses port 3389.

What well-known port numbers do SMTP, POP3, RDP, AND IMAP4 servers use?

SMTP uses TCP port 25, POP3 uses TCP port 110, RDP uses TCP port 3389, and IMAP4 uses TCP port 143.

Which destination Transport layer protocol and port number does a TFTP client use to transfer files over the network?

TFTP server respond to UDP messages sent to port 69.

Which of the following services use UDP? (Choose three.) A. DHCP B. SMTP C. SNMP D. FTP E. HTTP F. TFTP

A, C, F. DHCP, SNMP, and TFTP use UDP. SMTP, FTP, and HTTP use TCP.

Which of the following services use TCP? (Choose four.) A. DHCP B. SMTP C. SNMP D. FTP E. HTTP F. TFTP

B, C, D, E. SMTP, SNMP, FTP, and HTTP are connection oriented and use TCP.

What protocol is used to find the hardware address of a local device? A. RARP B. ARP C. IP D. ICMP E. BootP

B. Address Resolution Protocol (ARP) is used to find the hardware address from a known IP address.

You need to log in to a Unix server across a network that is not secure. Which of the following protocols will allow you to remotely administer this server securely? A. Telnet B. SSH C. SFTP D. HTTP

B. Secure Shell (SSH) allows you to remotely administer router, switches, and even servers securely.

What layer in the IP stack is equivalent to the transport layer of the OSI model? A. Application B. Host-to-host C. Internet D. Network access

B. The four layers of the IP stack (also called the DoD model) are application/process, host-to-host, internet, and network access. The host-to-host layer is equivalent to the transport layer of the OSI model.

What Transport layer protocol does a DNS server use?

Both TCP and UDP! A DNS server uses TCP port 53 for zone transfers and UDP port 53 for name resolutions. Notice that DNS uses both TCP and UDP. Whether it opts for one or the other depends on what it's trying to do.

Which statements are true regarding ICMP packets? (Choose two.) A. They acknowledge receipt of a TCP segment B. They guarantee datagram delivery C. They can provide hosts with information about network problems D. They are encapsulated within IP datagrams E. They are encapsulated within UDP datagrams

C, D. Internet Control Message Protocol (ICMP) is used to send error messages through the network, but ICMP does not work alone. Every segment or ICMP payload must be encapsulated within an IP datagram (or packet).

You want to implement a mechanism that automates the IP configuration, including IP address, subnet mask, default gateway, and DNS information. Which protocol will you use to accomplish this? A. SMTP B. SNMP C. DHCP D. ARP

C. Dynamic Host Configuration Protocol (DHCP) is used to provide IP information to hosts on your network. DHCP can provide a lot of information, but the most common is IP address, subnet mask, default gateway, and DNS information.

You need to make sure that the time is consistent across all your network devices. What protocol do you need to run on your network? A. FTP B. SCP C. NTP D. RTP

C. Network Time Protocol will ensure a consistent time across network devices on the network.

Which of the following protocols is used by email servers to exchange messages with one another? A. POP3 B. IMAP C. SMTP D. HTTP

C. SMTP is used by a client to send mail and by that server to send mail to another server. POP3 and IMAP are used by clients to retrieve their mail from the server that store it until it is retrieved. HTTP is only used with web-based mail services.

Which of the following uses both TCP and UDP? A. FTP B. SMTP C. Telnet D. DNS

D. DNS uses TCP for zone exchanges between servers and UDP when a client is trying to resolve a hostname to an IP address.

You need to transfer files between two hosts. Which protocol can you use? A. SNMP B. RIP C. NTP D. FTP

D. File Transfer Protocol (FTP) can be used to transfer files between two systems.

You need to have secure communications using HTTPS. What port number is used by default? A. 69 B. 23 C. 21 D. 443

D. HTTPS, or secure HTTP, uses port 443 by default.

The OSI model has seven layers and the DoD has four. At which layer does SMTP work in both models? A. Network B. Transport C. Session D. Application E. Internet

D. SMTP resides at the Application layer of the OSI and DoD models.

What protocol is at the heart of the ping and tracert commands in a Windows operating system?

ICMP is the protocol that the ping and tracert commands rely on. If you're having trouble getting pings and traceroutes through a router, you might need to check if ICMP is being allowed through.

Which protocol dynamically reports errors to source hosts by using IP directly to build packets?

ICMP uses IP directly to build error-reporting packets that are transmitted back to the originating source host when issues arise during the delivery of data packets. ICMP is also used during Ping and some Traceroute operations.

Which ports does the protocol MGCP use?

MGCP uses ports 2427 and 2727.