IST 201 Intro to networking Chapter 8

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 Codes at the beginning of each routing table entry are used to identify the type of route or how the route was learned. A code of "O" indicates the route was learned from OSPF

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

IPv4 has a 32-bit address space.​ IPv4 has a 32-bit address space, providing 4,294,967,296 unique addresses, but only 3.7 billion are assignable, a limit due to address reservation for multicasting and testing. IPv4 does not provide native support for IPsec. IPv6 has a simplified header with fewer fields than IPv4 has

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.

This contains a 32-bit binary value that represents the destination IPv4 address of the packet. The destination IPv4 address is a unicast address, multicast ad

Destination IPv4 address

This 128-bit field identifies the IPv6 address of the receiving host

Destination IPv6 address

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. Statics routes are manually configured and do not adjust to changes in the networking topology and are not advertised to neighboring routers

Which field in an IPv6 packet is used by the router to determine if a packet has expired and should be dropped? No Route to Destination Hop Limit Address Unreachable TTL

Hop Limit ICMPv6, like IPv4, sends a Time Exceeded message if the router cannot forward an IPv6 packet because the packet expired. However, IPv6 packet does not have a TTL field. Instead, it used the Hop Limit field to determine if the packet has expired.

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

What was the reason for the creation and implementation of IPv6? to make reading a 32-bit address easier to relieve IPv4 address depletion to allow NAT support for private addressing to provide more address space in the Internet Names Registry

to relieve IPv4 address depletion IPv4 addressing space is exhausted by the rapid growth of the Internet and the devices connected to the Internet. IPv6 expands the IP addressing space by increasing the address length from 32 bits to 128 bits, which should provide sufficient addresses for future Internet growth needs for many years to come

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. The best-effort delivery process guarantees that all packets that are sent are received. Network layer IP protocols manage the communication sessions if connection-oriented transport services are not available. Connectionless acknowledgements are used to request retransmission.

Upper-layer connection-oriented protocols keep track of the data received and can request retransmission from the upper-level protocols on the sending host. When connectionless protocols are in use at a lower layer for the OSI model, upper-level protocols may need to work together on the sending and receiving hosts to account for retransmit lost data. In some cases, this is not necessary, because for some applications a certain amount of data loss is tolerable

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

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

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. The MTU is passed to the network layer by the data link layer. The network layer depends on the higher level layers to determine the MTU. To increase speed of delivery, the network layer ignores the MTU.

The 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 that packet can be when it is forwarded. When packets are received on one medium and forwarded on a medium with a smaller MTU, the network layer device can fragment the packet to accommodate the smaller size

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

increased the IP address space uses a simpler header to provide improved packet handling

Which IPv4 address can a host use to ping the loopback interface? 127.0.0.0 126.0.0.0 127.0.0.1 126.0.0.1

127.0.0.1 (topic 8.4.0) a host can ping the loopback interface by sending a packet to a special IPv4 address within the network

This field is used to identify the next level protocol. The 8-bit binary value indicates the data payload type that the packet is carrying, which enables the network layer to pass the data to the appropriate upper-layer protocol. Common values include ICMP(1) , TCP(6), and UDP(17)

Protocol

Contains an 8 -bit binary value that is used to limit the lifetime of a packet.

Time to Live(TTL)

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

True Routers can be configured with static routes and with a dynamic routing protocol.

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.

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 The show ip route command is used to view the routing table

What information is added during encapsulation at OSI Layer 3? source and destination application protocol source and destination port number source and destination IP address source and destination MAC

source and destination IP address IP is a Layer 3 protocol. Layer 3 devices can open the Layer 3 header to inspect the Layer 3 header which contains IP-related information including the source and destination IP address

Which field in an IPv4 packet header will typically stay the same during its transmission? Destination Address Flag Packet Length Time-to-Live

Destination address The value in the Destination Address filed in an IPv4 header will stay the same during its transmission. The other options might change during its transmission

Formerly called the type of service(ToS) field, the DS field is an 8-bit field used to determine the priority of each packet. The 6 most significant bits of the DS field are the differentiated serves code point(DSCP) bits and the last two bits are the explicit congestion notification(ECN) bits

Differentiated Services or DIffServe(DS)

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

Header Checksum

This is used to detect corruption in the IP header

Header checksum

This 16-bit field indicates the length of the data portion of payload of the IPv6 packet. This does not include the length of the IPv6 header, which is fixed 40-bit header

Payload length

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

Protocol The protocol field identifies the upper layer protocol that is carried inside the IP packet. Common protocols are TCP,UDP, and ICMP

This contains a 32-bit binary value that represents the source IPv4 address of the packet. The source IPv4 address is always a unicast address

Source IPv4 address

This 128-bit field identifies the IPv6 address of the sending host

Source IPv6 address

A computer has to send a packet to a destination host in the same LAN. How will the packet be sent? The packet will first be sent to the default gateway, and then from the default gateway it will be sent directly to the destination host. The packet will be sent to the default gateway first, and then, depending on the response from the gateway, it may be sent to the destination host. The packet will be sent directly to the destination host. The packet will be sent only to the default gateway.

The packet will be sent directly to the destination host. 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

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

default route A default route is known as a gateway of last resort

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

Best effort Best effort delivery does not guarantee packets will be delivered to the destination

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

Contains a 4-bit binary value set to 0100 that identifies this as an IPv4 packet.

Version

Which command can be used on a Windows host to display the routing table? netstat -r show ip route tracert netstat -s

netstat -r On a Windows host, either the route print or netstat -r commands can be used to display the host routing table. The show ip route command is used on a router to display it routing table. The netstat -s command is used to display per-protocol statistics. The tracert command is used to display the path that a packet travels to its destination

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

Which layer is responsible for taking an IP packet and preparing it for transmission over the communications medium? physical layer network layer data link layer transport layer

data link layer The data link layer receives IP packets from the network layer and encapsulates them for transmission of the medium.

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 The IP header fields that identify where the packet is originated and where it is going

Which information is used by routers to forward a data packet toward its destination? source data-link address source IP address destination data-link address destination IP address

destination IP address 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

This 8-bit field replaces the IPv4 TTL field. This value is decremented by a value of 1 by each router that forwards the packet.

Hop limit

This 8-bit field is equivalent to the IPv4 protocol field. it indicates the data payload type that the packet is carrying, enabling the the network layer to pass the data to the appropriate upper-layer protocol.

Next header

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.

This 8-bit field is equivalent to the IPv4 Differentiated Services (DS) field. Handles traffic prioritization

Traffic class

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. a router is not needed to forward packets between local hosts on the network

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 Transport layer PDU's, called segments are encapsulated at the network layer by IPv4 and IPv6 into packets

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 Fragmentation is the process of splitting up IP packets to travel over a medium with a smaller MTU(maximum transmission unit)

Which characteristic describes an IPv6 enhancement over IPv4?​ Both IPv4 and IPv6 support authentication, but only IPv6 supports privacy capabilities. IPv6 addresses are based on 128-bit flat addressing as opposed to IPv4 which is based on 32-bit hierarchical addressing. The IPv6 header is simpler than the IPv4 header is, which improves packet handling. The IPv6 address space is four times bigger than the IPv4 address space.​

The IPv6 header is simpler than the IPv4 header is, which improves packet handling. IPv6 addresses are based on 128-bit hierarchical addressing, and the IPv6 header has been simplified with fewer fields, improving packet handling. IPv6 natively supports authentication and privacy capabilities as opposed to IPv4 that needs additional features to support those. The IPv6 address space is many times bigger than ipv4 address space.