Networking Ch8 Network Layer/IPv4 and IPv6 Packets/Host-Default Gateway/Router Packet Forwarding Decision

How does the network layer use the MTU value? The network layer depends on the data link layer to set the MTU, and adjusts the speed of transmission to accommodate it. To increase speed of delivery, the network layer ignores the MTU. The network layer depends on the higher level layers to determine the MTU. The MTU is passed to the network layer by the data link layer.

The MTU is passed to the network layer by the data link layer. MTU is passed to the network layer by the data link layer. The data link layer indicates to the network layer the MTU for the medium that is being used. The network layer uses that information to determine how large the packet can be when it is forwarded.

Which default gateway statement is true? A default gateway is required to send packets to other hosts on the local network. The default gateway address is the IP address of a switch on a remote network. The default gateway address is the IP address of the router on the local network. Traffic can only be forwarded outside the local network if there is no default gateway.

The default gateway address is the IP address of the router on the local network.

default gateway

The default gateway is the network device (i.e., router or Layer 3 switch) that can route traffic to other networks. If you use the analogy that a network is like a room, then the default gateway is like a doorway. If you want to get to another room or network you need to find the doorway. The default gateway address is the IP address of the router on the local network. On a network, a default gateway is usually a router with these features: It has a local IP address in the same address range as other hosts on the local network. It can accept data into the local network and forward data out of the local network. It routes traffic to other networks. A default gateway is required to send traffic outside of the local network. Traffic cannot be forwarded outside the local network if there is no default gateway, the default gateway address is not configured, or the default gateway is down.

Static routing has the following characteristics:

A static route must be configured manually. The administrator needs to reconfigure a static route if there is a change in the topology and the static route is no longer viable. A static route is appropriate for a small network and when there are few or no redundant links. A static route is commonly used with a dynamic routing protocol for configuring a default route.

Which IPv4 address can a host use to ping the loopback interface?

127.0.0.1

Which layer is responsible for taking an IP packet and preparing it for transmission over the communications medium?

Data Link Layer

Which field in an IPv4 packet header will typically stay the same during its transmission?

Destination Address

The dynamic routing protocol will automatically do as follows:

Discover remote networks Maintain up-to-date routing information Choose the best path to destination networks Attempt to find a new best path if the current path is no longer available

What is the term for splitting up an IP packet when forwarding it from one medium to another medium with a smaller MTU? encapsulation fragmentation segmentation serialization

Fragmentation

Which field is used to detect corruption in the IPv4 header? Header Checksum Time to Live Protocol Differentiated Services (DS)

Header Checksum

Which field in an IPv6 packet is used by the router to determine if a packet has expired and should be dropped?

Hop Limit

Which three options are major issues associated with IPv4? (Choose three.) IP address depletion increased network complexity and Internet routing table expansion always on connections lack of end-to-end connectivity global and political boundaries too many IPv4 addresses available

IP address depletion increased network complexity and Internet routing table expansion lack of end-to-end connectivity

Which statement accurately describes a characteristic of IPv4? An IPv4 header has fewer fields than an IPv6 header has.​ IPv4 natively supports IPsec.​ IPv4 has a 32-bit address space.​

IPv4 has a 32-bit address space.​

The show ip route privileged EXEC mode command is used to view the IPv4 routing table on a Cisco IOS router. Common route sources (codes) include these:

L - Directly connected local interface IP address C - Directly connected network S - Static route was manually configured by an administrator O - OSPF D - EIGRP

Which statement about host forwarding decisions is true? A host cannot ping itself. A remote destination host is on the same local network as the sending host. Local hosts can reach each other without the need of a router. Routing is enabled on switches to discover the best path to a destination.

Local hosts can reach each other without the need of a router.

Which field includes common values such as ICMP (1), TCP (6), and UDP (17)? Header Checksum Time to Live Protocol Differentiated Services (DS)

Protocol

Which is true of the IPv6 packet header? The Hop Limit field replaces the IPv4 Time to Live field. The Source and Destination IPv6 addresses change while travelling from source to destination. The Time to Live field replaces the DiffServ field. The Version field identifies the next header.

The Hop Limit field replaces the IPv4 Time to Live field.

Which characteristic describes an IPv6 enhancement over IPv4?​

The IPv6 header is simpler than IPv4 header, which improves packet handling

Which statement is correct about IPv4 packet header fields? The source and destination IPv4 addresses remain the same while travelling from source to destination. The Time to Live field is used to determine the priority of each packet. The Total Length and Header Checksum fields are used to reorder a fragmented packet. The Version field identifies the next level protocol.

The source and destination IPv4 addresses remain the same while travelling from source to destination.

Which is a characteristic of static routes? They are manually configured. They are advertised to directly connected neighbors. They are appropriate when there are many redundant links. They automatically adjust to a change in network topology.

They are manually configured.

Which OSI layer sends segments to be encapsulated in an IPv4 or IPv6 packet? data link layer network layer transport layer session layer

Transport Layer

True or False? A router can be configured with a combination of both static routes and a dynamic routing protocol. True False

True

When a connectionless protocol is in use at a lower layer of the OSI model, how is missing data detected and retransmitted if necessary?

Upper-layer connection-oriented protocols keep track of the data received and can request retransmission from the upper-level protocols on the sending host.

What does a code of "O" indicate next to a route in the routing table? a directly connected route a route with an administrative distance of 0 a gateway of last resort a route learned dynamically from OSPF

a route learned dynamically from OSPF

Network layer protocols perform four basic operations:

addressing end devices, encapsulation, routing, and de-encapsulation.

Which delivery method does not guarantee that the packet will be delivered fully without errors? connectionless best effort media independent

best effort

This type of route is also known as a gateway of last resort. static route remote route default route directly connected route

default route

When a router receives a packet, what information must be examined in order for the packet to be forwarded to a remote destination?

destination IP address

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

destination IP address

What are the two most commonly referenced fields in an IPv4 packet header that indicate where the packet is coming from and where it is going? (Choose two.) destination IP address protocol Time to Live source IP address Differentiated Services (DS)

destination IP address source IP address

Network Address Translation (NAT)

is a technology commonly implemented within IPv4 networks. NAT provides a way for multiple devices to share a single public IPv4 address. However, because the public IPv4 address is shared, the IPv4 address of an internal network host is hidden. This can be problematic for technologies that require end-to-end connectivity.

Which is true of the IPv6 header? it consists of 20 octets. it consists of 40 octets. it contains 8 header fields. it contains 12 header fields.

it consists of 40 octets. it contains 8 header fields.

Which two commands could be entered on a Windows host to view its IPv4 and IPv6 routing table? (Choose two.) netroute -l netstat -r print route route print print net

netstat -r route print

What is the command used on a Cisco IOS router to view the routing table? netstart -r route print show ip route show routing table

show ip route

What information is added during encapsulation at OSI Layer 3?

source and destination IP address

What was the reason for the creation and implementation of IPv6? to make reading a 32-bit address easier

to relieve IPv4 address depletion

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

The packet will be sent directly to the destination host.

Which two options are improvements provided by IPv6 as compared to IPv4? (Choose two.) header supports additional fields for complex packets increased the IP address space standardizes the use of NAT supports class-based networks uses a simpler header to provide improved packet handling

standardizes the use of NAT uses a simpler header to provide improved packet handling

The fields in the IPv6 packet header include

An IPv6 packet may also contain extension headers (EH), which provide optional network layer information. Extension headers are optional and are placed between the IPv6 header and the payload. EHs are used for fragmentation, security, to support mobility and more.