Networking Basics 12 - 14

Which destination address is used in an ARP request frame?

FFFF.FFFF.FFFF

What addresses are mapped by ARP?

IPv4 address to a destination MAC address

A computer has to send a packet to a destination host in the same LAN. How will the packet be sent?

If the destination host is in the same LAN as the source host, there is no need for a default gateway. A default gateway is needed if a packet needs to be sent outside the LAN.

If the default gateway is configured incorrectly on a host, what is the impact on communications?

In data communication, the default gateway device is involved only when a host needs to communicate with other hosts on another network. The default gateway address identifies a network device that a host device uses to communicate with devices on other networks. The default gateway device is not used when a host communicates with other hosts on the same network.

What is a benefit of adding a router within an IP network?

Routers can divide or segment a network. Because routers do not forward broadcasts they can keep broadcasts isolated to the local network.

What action will a router take when it receives a frame with a broadcast MAC address?

Routers do not forward broadcasts to other networks. Routers examine broadcasts to determine if they need to act on the broadcast, such as an ARP request or a DHCP DISCOVER message. If the router does not need to respond to the broadcast, it is dropped.

Which table does a router use to determine which interface to use to send packets to the destination network?

Routing tables contain the addresses of networks, and the best path to reach those networks. Routers use the routing tables to determine which interface to use to forward a message to its intended destination.

What important information is examined in the Ethernet frame header by a Layer 2 device in order to forward the data onward?

The Layer 2 device, such as a switch, uses the destination MAC address to determine which path (interface or port) should be used to send the data onward to the destination device.

Which characteristic describes the default gateway of a host computer?

The default gateway is the IP address of an interface on the router on the same network as the sending host.

Which address should be configured as the default gateway address of a client device?

The default gateway is used when a host needs to send messages to destinations that are located in remote networks. The default gateway address is configured on the host with the IPv4 address of the router interface that is connected to the same local network as the host.

Which information is used by routers to forward a data packet toward its destination?

The destination IP address is the IP address for the receiving device. This IP address is used by routers to forward the packet to its destination.

Which three IPv4 network addresses are private IP addresses? (Choose three.)

The reserved private IPv4 network addresses include 10.0.0.0 to 10.255.255.255, 172.16.0.0 to 172.31.255.255, and 192.168.0.0 to 192.168.255.255.

What are two reasons to install routers to segment a network? (Choose two.)

There are a number of reasons to use routers to divide a network into smaller segments. Expanding the network into a different geographic location may require the use of routers at both locations. Another reason is to limit broadcasts that must be processed by all devices on the network segment. Routers do not forward broadcast traffic off the local network segment.

Which statement describes the treatment of ARP requests on the local link?

They are received and processed by every device on the local network.

What statement describes a characteristic of MAC addresses?

They are the physical address of the NIC or interface.

Typically, which network device would be used to perform NAT for a corporate environment?

Typically, the translation from private IP addresses to public IP addresses is performed on routers in corporate environments. In a home environment, this device might be an access point that has routing capability or the DSL or cable router.

Which two characteristics describe MAC addresses? (Choose two.)

physical address assigned to the NIC. The MAC address is referred to as a physical address because it is assigned by the manufacturer to the NIC. MAC addresses are contained in the Layer 2 header. IP addresses are Layer 3 addresses and are logical addresses that are assigned either dynamically through DHCP or manually configured. Routers use destination IP addresses to choose the best path over which to forward the packets.

What is one function of the ARP protocol?

resolving an IPv4 address to a MAC address

Which device is used to transfer data from one IP local network to a remote network?

router

What is the purpose of configuring a default gateway address on a host?

to identify the device that allows local network computers to communicate with devices on other networks

What are two functions of MAC addresses in a LAN? (Choose two.)

to uniquely identify a node on a network. to allow the transfer of frames from source to destination.

Which three settings must be configured on a PC in order for it to communicate with devices located across the internet? (Choose three.)

A PC must be configured with an IP address, subnet mask, and a default gateway address in order to be able to communicate with devices located on a different IP network. This includes devices that are reached through the internet.

If the default gateway is configured incorrectly on the host, what is the impact on communications?

A default gateway is only required to communicate with devices on another network. The absence of a default gateway does not affect connectivity between devices on the same local network.

The default configuration on a home wireless router provides which type of addresses to devices using DHCP?

By default, home wireless routers give out private IPv4 addresses to devices on the home network. These addresses are usually in the 192.168.0.0 reserved range.

Which type of intermediary device acts as a boundary between a home wireless network and the internet?

A wireless router acts as a network boundary for the attached IP networks. Most home network wireless routers connect a privately addressed local LAN to an external IP network connected to an ISP.

What is the purpose of NAT?

NAT translates host internal private IP addresses to one or more registered public IP addresses in order for the host to access sites through the internet.

What is the primary advantage of using NAT?

Network Address Translation (NAT) can allow a large group of privately addressed hosts to share one or more registered public IP addresses in order to route packets over the internet.

What role does a router play on a network?

When a computer sends a packet onto the network, the packet includes a source and destination IP address. Routers use the destination IP address in a packet to forward the packet to the correct destination network.

What action does the router take when it does not find a route to the destination network in its routing table?

When there is no route to the destination network contained in the routing table, the router drops the packet.