Chapter 5 Flashcards
(17 cards)
Which protocol provides connectionless network layer services?
A. IP
B. TCP
C. UDB
D. OSI
A. IP provides connectionless network layer services. TCP is connection oriented. UDP
is connectionless, but it works at the transport layer
What two commands can be used to view a host’s routing table?
netstat -r and route print.
Select three pieces of information about a route that a routing table contains.
A. Next-hop
B. Source address
C. Metric
D. Destination network address
E. Last hop
F. Default gateway
A, C, D. A routing table contains the next-hop, metric, and destination network
address. Routers do not need the source address, last hop, or default gateway to find a
path to a network.
What kinds of problems are caused by excessive broadcast traffic on a network segment? (Choose three.)
A. Consumes network bandwidth
B. Increases overhead on network
C. Requires complex address schemes
D. Interrupts other host functions
E. Divides networks based on ownership
F. Advanced hardware required
A, B, D. Reduced network bandwidth, increased overhead, and reduced host functions
are three potential results of excessive broadcasts. The other answers can be part of a
solution to the problem of excessive broadcasts.
What are three key factors to consider when grouping hosts into a common network?
Purpose, ownership, and geographic location are three key ways to divide a network.
Which of the following are not functions of the network layer? (Choose two.)
A. Routing
B. Addressing packets with an IP address
C. Delivery reliability
D. Application data analysis
E. Encapsulation
F. Decapsulation
C, D. Delivery reliability is a transport layer concern. Application data analysis is a
concern of the presentation layer. Routing, addressing packets with an IP address,
encapsulation, and decapsulation are functions of the network layer.
Which of the following are true about IP? (Choose two.)
A. IP stands for International Protocol.
B. It is the most common network layer protocol.
C. It analyzes presentation layer data.
D. It operates at OSI Layer 2.
E. It encapsulates transport layer segments.
B, E. IP stands for the Internet Protocol, which operates at OSI Layer 3 (the network
layer). IP encapsulates transport layer segments. IP does not look inside the upper-level
PDU, so it has no knowledge of the presentation layer data.
What is the name of the process of removing the OSI Layer 2 information from an IP packet?
Decapsulation
Which of the following is true about IP?
A. It is connection oriented.
B. It uses application data to determine the best path.
C. It is used by both routers and hosts.
D. It is reliable
C. Routers and hosts use IP. B is incorrect because IP uses addressing information in
the header to determine the best path for a packet. D is incorrect because IP is a “best
effort” unreliable protocol.
Which of the following are true about network layer encapsulation? (Choose two.)
A. It adds a header to a segment.
B. It can happen many times on the path to the destination host.
C. It is performed by the last router on the path.
D. Both source and destination IP addresses are added.
E. It converts transport layer information into a frame.
A, D. Network layer encapsulation adds a header to a segment and adds both source
and destination IP addresses. Network layer encapsulation happens only on the original
host; other devices can read the data, but they do not remove or alter it until the destination network is reached. The network layer converts transport layer segments into
packets.
Which of the following are true about TCP and IP? (Choose two.)
A. TCP is connectionless and IP is connection oriented.
B. TCP is reliable and IP is unreliable.
C. IP is connectionless and TCP is connection oriented.
D. TCP is unreliable and IP is reliable.
E. IP operates at the transport layer.
B, C. TCP is reliable and connection oriented. IP is unreliable and connectionless. IP
operates at the network layer.
Why is IP “media independent”?
A. It encapsulates Layer 1 instructions.
B. It works the same on all Layer 1 media.
C. It carries both video and voice data.
D. It works without Layer 1 media
B. IP encapsulates OSI Layer 4 data. IP can carry voice, video, and other types of data,
but “media independent” refers to the OSI Layer 1 medium that carries the data across
the networks. IP, or any other communication, can occur without a physical (OSI Layer
1) medium.
TCP is a __________ layer protocol.
transport
How many bits are in an IPv4 address?
- There are four octets (8 bits each) in an IPv4 address.
Which of the following are true about static and dynamic routing? (Choose two.)
A. Static routing requires a routing protocol such as RIP.
B. A default route is a dynamic route.
C. Dynamic routing adds packet-processing overhead.
D. Administrative overhead is reduced with static routing.
E. Routers can use static and dynamic routing simultaneously.
C, E. Dynamic routing adds packet-processing overhead, and routers can use static and
dynamic routing simultaneously. Static routing does not require a routing protocol. A
default route is an example of a static route. Because static routes must be manually
configured and updated, they add to administrative overhead.
What can happen when the TTL is 1? (Choose two.)
A. The packet can be successfully delivered if it is destined for a directly connected
network.
B. TCP controls in the packet will add hops to the TTL.
C. The packet will be dropped by the next router unless that router has an interface on
the destination network.
D. The packet will be returned to the source host.
E. The packet will be returned to the previous router.
A, C. When the TTL is 1, it has one hop remaining to be either delivered or discarded.
IP does not provide return notification of dropped packets. TCP controls at the destination will request a packet retransmission, but the TCP PDU is never accessed en route.
IP is connectionless and will occasionally drop a packet en route to a destination IP address. If packets are dropped, how will messages be completed?
A. Only the IP portion of the packet is dropped, but the TCP portion continues to the
last router.
B. The routing protocols will carry the TCP information to the previous-hop router,
which sends a reverse notification to the source.
C. The routing protocols, such as RIP, are connection oriented and will contact the
source host.
D. The destination host is expecting the packet and will send a request if it does not
arrive.
E. The IP header contains the source address so that the packet can be returned by the
router that receives the packet when the TTL is 0.
D. The destination host will send a request if the packet does not arrive. IP is connectionless, so there is no reliability built into the protocol. Previous packets with TCP
information have arrived at the destination host with “expectational” information.
Routing protocols, such as RIP, are used by routers to share route information; they are
not involved in TCP/IP reliability.
