ITN Unit 9

What is ARP's two main functions?

• Resolving IPv4 Addresses to MAC addresses

• Communicating with the Router

• Maintaining the table of IPv4 to MAC addresses

• Changing the MAC address

A host is trying to send a packet to a device on a remote LAN segment, but there are currently no mappings in its ARP cache. How will the device obtain a destination MAC address?

• It will send the frame and use its own MAC address as the destination

• It will send an ARP request for the MAC address of the destination device

• It will send the frame with a broadcast MAC address

• It will send a request to the DNS server for the destination MAC address

• It will send an ARP request for the MAC address of the default gateway

What are two problems that can be caused by a large number of ARP request and reply messages? (Choose two.)

• Switches become overloaded because they concentrate all the traffic from the attached subnets.

• The ARP request is sent as a broadcast, and will flood the entire subnet.

• The network may become overloaded because ARP reply messages have a very large payload due to the 48-bit MAC address and 32-bit IP address that they contain

• A large number of ARP request and reply messages may slow down the switching process, leading the switch to make many changes in its MAC table

• All ARP request messages must be processed by all nodes on the local network

The switches have a default configuration. Host A needs to communicate with host D, but host A does not have the MAC address for the default gateway. Which network devices will receive the ARP request sent by host A?

• only host D

• only hosts A, B, C, and D

• only hosts B and C

• only hosts B, C, and router R1

• only hosts A, B, and C

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 network domain of the destination host

• the IP address of the default gateway

• the MAC address of the destination host

• the MAC address of the default gateway

What commands display the ARP table? (Choose two)

• show ip arp

• address table -s

• arp -a

• table -a

Sending many many fake ARP requests on a network is called

• DDoS

• ARP Poisoning

• Man in the Middle

• Reconnaissance

What are two ICMPv6 messages that are not present in ICMP for IPv4? (Choose two)

• Neighbor Solicitation

• Destination Unreachable

• Host Confirmation

• Time Exceeded

• Router Advertisement

A client is using SLAAC to obtain an IPv6 address for its interface. After an address has been generated and applied to the interface, what must the client do before it can begin to use this IPv6 address?

• It must send a DHCPv6 INFORMATION-REQUEST message to request the address of the DNS server.

• It must send a DHCPv6 REQUEST message to the DHCPv6 server to request permission to use this address.

• It must send an ICMPv6 Router Solicitation message to determine what default gateway it should use.

• It must send an ICMPv6 Neighbor Solicitation message to ensure that the address is not already in use on the network

Two pings were issued from a host on a local network. The first ping was issued to the IP address of the default gateway of the host and it failed. The second ping was issued to the IP address of a host outside the local network and it was successful. What is a possible cause for the failed ping?

• The default gateway is not operational.

• The default gateway device is configured with the wrong IP address.

• Security rules are applied to the default gateway device, preventing it from processing ping requests.

• The TCP/IP stack on the default gateway is not working properly.