Networking Devices and Initial Configuration Module 7 - 9 Checkpoint Exam

What IPv4-related DNS record type is used by a DNS server in response to a host requesting for a web server address via the URL?

A record A DNS server uses an A record type for an IPv4 end device address. The AAAA record is for an IPv6 end device address. The MX record is used to map the domain name to mail exchange servers. The NS record indicates the authoritative name server.

What is a socket?

A socket is a combination of the source IP address and source port or the destination IP address and the destination port number.

What statement describes the function of the Address Resolution Protocol?

ARP is used to discover the MAC address of any host on the local network. When a PC wants to send data on the network, it always knows the IP address of the destination. However, it also needs to discover the MAC address of the destination. ARP is the protocol that is used to discover the MAC address of a host that belongs to the same network.

What is the protocol that is used to discover a physical address from a known logical address and what message type does it use?

ARP, broadcast An ARP request is broadcast to all devices on a LAN segment which seek the MAC address for a known IP address. Pings are used to verify connectivity between two devices, and DNS resolves URLs to IP addresses.

Which DHCP IPv4 message contains the following information?Destination address: 255.255.255.255Client IPv4 address: 0.0.0.0Default gateway address: 0.0.0.0Subnet mask: 0.0.0.0

DHCPDISCOVER A client will first send the DHCPDISCOVER broadcast message to find DHCPv4 servers on the network. This message will have the limited broadcast address, 255.255.255.255, as the destination address. The client IPv4 address, the default gateway address, and subnet fields will all be 0.0.0.0 because these have not yet been configured on the client. When the DHCPv4 server receives a DHCPDISCOVER message, it reserves an available IPv4 address to lease to the client and sends the unicast DHCPOFFER message to the requesting client. When the client receives the DHCPOFFER from the server, it sends back a DHCPREQUEST broadcast message. On receiving the DHCPREQUEST message, the server replies with a unicast DHCPACK message.

A DHCP configured PC boots up. What is the order of the messages that are sent and received by this PC in order to obtain an appropriate IP address?

DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPACK​

A user reports that the corporate web server cannot be accessed. A technician verifies that the web server can be accessed by its IP address. What are two possible causes of the problem? (Choose two.)

The DNS server address is misconfigured on the workstation. The fact that the web server can be accessed by its IP address indicates that the web server is working and there is connectivity between the workstation and the web server. However, the web server domain name is not resolving correctly to its IP address. This could be caused by a misconfiguration of the DNS server IP address on the workstation or the wrong entry of the web server in the DNS server.

A client is establishing a TCP session with a server. How is the acknowledgment number in the response segment to the client determined?

The acknowledgment number field is modified by adding 1 to the randomly chosen initial sequence number in response to the client. To establish a session with the client, the TCP server will acknowledge the receipt of the SYN segment from the client. The server sends a segment back to the client with the ACK flag set indicating that the acknowledgment number is significant.The value of the acknowledgment number field is equal to the randomly chosen initial sequence number (ISN) plus 1.

Which three statements describe a DHCP Discover message? (Choose three.)

The message comes from a client seeking an IP address. All hosts receive the message, but only a DHCP server replies. The destination IP address is 255.255.255.255.

Which two tasks can be performed by a local DNS server? (Choose two.)

Two important functions of DNS are to (1) provide IP addresses for domain names such as www.cisco.com, and (2) forward requests that cannot be resolved to other servers in order to provide domain name to IP address translation. DHCP provides IP addressing information to local devices. A file transfer protocol such as FTP, SFTP, or TFTP provides file sharing services. IMAP or POP can be used to retrieve an email message from a server.

What does a client application select for a TCP or UDP source port number?

a random value in the range of the registered ports The client randomly selects an available source port in the range of the registered ports.

When a computer is pinging another computer for the first time, what type of message does it place on the network to determine the MAC address of the other device?

an ARP request An ARP request is used to determine any unknown MAC address when the destination IP address is known. In an IPv4-based network, this request is sent as a Layer 2 broadcast.

A host device needs to send a large video file across the network while providing data communication to other users. Which feature will allow different communication streams to occur at the same time, without having a single data stream using all available bandwidth?

multiplexing Multiplexing is useful for interleaving multiple communication streams. Window size is used to slow down the rate of data communication. Port numbers are used to pass data streams to their proper applications. Acknowledgments are used to notify a sending device that a stream of data packets has or has not been received.

Which two commands could be used to check if DNS name resolution is working properly on a Windows PC? (Choose two.)

ping cisco.com nslookup cisco.com

Which two TCP header fields are used to confirm receipt of data? (Choose two.)

sequence number acknowledgment number Together the TCP sequence number and acknowledgment number fields are used by the receiver to inform the sender of the bytes of data that the receiver has accepted.

A user sends an HTTP request to a web server on a remote network. During encapsulation for this request, what information is added to the address field of a frame to indicate the destination?

the MAC address of the default gateway A frame is encapsulated with source and destination MAC addresses. The source device will not know the MAC address of the remote host. An ARP request will be sent by the source and will be responded to by the router. The router will respond with the MAC address of its interface, the one which is connected to the same network as the source.