Chapter 8 TCP/IP Internetworking I

Which of the following is connectionless? A) TCP. B) UDP. C) Both A and B D) Neither A nor B

B) UDP

A router will discard a packet if the TTL value reaches ________. A) 0 B) 1 C) 128 D) 256

A) 0

In a routing table, Rows 47, 3,497, and 30,451 match the destination IP address of an arriving packet's IP address. Which row will the router look at first when trying to find matches? A) 1 B) 47 C) 30,451 D) The default row.

A) 1

If the sending host does not do MTU discovery, the largest packet it can send is ________. A) 1,280 octets B) 65,536 octets C) 65,536 octets minus the 40 octets of the main headers D) None of the above. The sending host must do MTU discovery.

A) 1,280 octets

In the mask /14, how many 1s are there? A) 14 B) 16 C) 24 D) None of the above

A) 14

Row 2707 has the mask /16 and the reliability metric 20. Row 4400 has the mask /14 and the reliability metric 10. Which row will the router choose if both are matches? A) 2707. B) 4400. C) Either A or B D) The router will choose the default row.

A) 2707

Row 2707 has the mask /16 and the speed metric 20. Row 4400 has the mask /16 and the speed metric 10. Which row will the router choose if both are matches? A) 2707. B) 4400. C) Either A or B D) The router will choose the default row.

A) 2707

The network part of an IP address is ________ bits long. A) 8 B) 16 C) 32 D) We cannot say.

A) 8

A(n) ________ must find the best-matching row in its ________ table by comparing several row matches. A) Ethernet switch, switching B) router, routing C) Both A and B D) Neither A not B

A) Ethernet switch, switching

A TCP ________ segment is a request to close a connection. A) FIN B) ACK C) Close D) Disconnect

A) FIN

Four-way closes use ________ segments. A) FIN B) RST C) Both A and B D) Neither A nor B

A) FIN

Which of the following permits fragmentation by routers along a packet's route? A) IPv4. B) IPv6. C) Both A and B D) Neither A nor B

A) IPv4

What does a router do with ARP request messages? A) It broadcasts them. B) It sends them directly to the destination host. C) Both A and B D) Neither A nor B

A) It broadcasts them.

Which TCP/IP interior dynamic routing protocol is good for small internets if security is not a serious concern? A) RIP. B) BGP. C) OSPF. D) Both A and C

A) RIP

________ is an interior dynamic routing protocol. A) RIP B) BGP C) Both A and B D) Neither A nor B

A) RIP

For 100,000 addresses, which will have fewer rows? A) Router table. B) Ethernet switch table. C) Both will be about the same length.

A) Router table.

Which of the following is one of the three parts of an IP address? A) Subnet part. B) Mask. C) Both A and B D) Neither A nor B

A) Subnet part

Which of the following can handle an application message that is one megabyte in size? A) TCP. B) UDP. C) Both A and B D) Neither A nor B

A) TCP

Which of the following is reliable? A) TCP B) IP C) Both A and B D) Neither A nor B

A) TCP

One-bit fields are called ________ fields. A) binary B) flag C) ACK D) None of the above

A) binary

Pinging sends ICMP ________ messages to the target host. A) echo B) error advisement C) Both A and B D) Neither A nor B

A) echo

To see if a target host can be reached, you normally would send it an ICMP ________ message. A) echo B) error advisement C) Both A and B D) Neither A nor B

A) echo

Compared to normal routing, decision caching is ________. A) faster B) less dangerous C) Both A and B D) Niether A nor B

A) faster

According to the IETF standards, if a router receives a series of packets from the same IP address to the same IP address, it should ________. A) go through the entire process for each packet B) cache the decision made for the first packet and use this decision on subsequent packets C) skip the first step in the routing process but go through other steps for each subsequent packet D) None of the above

A) go through the entire process for each packet

An autonomous system is free to select whatever ________ dynamic routing protocol it wishes. A) interior B) exterior C) Both A and B

A) interior

If someone says that a 1-bit flag is set, this means that it is given the value ________. A) 0 B) 1 C) Either of the above

B) 1

The main version of Internet Protocol in use today is IP version ________. A) 1 B) 4 C) 5 D) 6

B) 4

Which of the following can route non-IP packets? A) OSPF. B) EIGRP. C) Both A and B D) Neither A nor B

B) EIGRP

There is a row for each address in a(n) ________. A) Router table B) Ethernet switch table C) Both of the above D) Neither A nor B

B) Ethernet switch table

Which of the following is connectionless? A) TCP B) IP C) Both A and B D) Neither A nor B

B) IP

________ operates at the internet layer. A) TCP B) IP C) Both A and B D) Neither A nor B

B) IP

The first Step in the Routing process involves ________. A) selecting the best match row B) comparing the packet's destination IP address to all rows C) comparing the packet's destination IP address to matching rows D) selecting an interface

B) comparing the packet's destination IP address to all rows

UDP is ________. A) connection-oriented B) connectionless C) Both A and B D) Neither A nor B

B) connectionless

In IPv6, the payload length gives the number of octets in the ________. A) entire packet B) entire packet minus the main header C) entire packet minus the main and extension headers D) entire packet minus the extension headers

B) entire packet minus the main header

For human reading, IPv6 address are written in ________. A) decimal B) hexadecimal C) binary D) Elvish

B) hexadecimal

In packet fragmentation and reassembly, the ________ field is used. A) version B) identification C) protocol D) Diff-Serv

B) identification

For human reading, in IPv6 addresses, letters should be written in ________. A) uppercase B) lowercase C) Both A and B D) Neither A nor B

B) lowercase

Routers usually are connected in a ________ topology. A) point-to-point B) mesh C) hierarchical D) bus

B) mesh

For a given volume of traffic, which are more expensive? A) switches. B) routers. C) Both of the above are about equally expensive.

B) routers

In the mask 255.255.255.0, how many 1s are there? A) 8 B) 16 C) 24 D) None of the above

C) 24

Deciding how to send the packet back out is Step ________ in the routing process. A) 1 B) 2 C) 3 D) 4

C) 3

A mask has ________ bits. A) 8 B) 16 C) 32 D) We cannot say.

C) 32

The total length of an IP address is ________ bits. A) 8 B) 16 C) 32 D) We cannot say.

C) 32

For human reading, symbols in IPv6 addresses are written in groups of ________. A) 1 B) 2 C) 4 D) 16

C) 4

58) Which of the following is contributing to the exhaustion of IPv4 addresses? A) The growing number of hosts in Asia. B) The growing number of mobile devices. C) Both A and B D) Neither A nor B

C) Both A and B

ARP is used to find the destination data link layer destination addresses of ________. A) destination hosts B) routers C) Both A and B D) Neither A nor B

C) Both A and B

In TCP/IP, routing means ________. A) the process that routers use to forward incoming packets B) the process that routers use to exchange routing table information C) Both A and B D) Neither A nor B

C) Both A and B

The default row ________. A) always has the mask /32 B) will always match the IP address of an incoming packet C) Both A and B D) Neither A nor B

C) Both A and B

The encapsulating security protocol can be used in ________. A) IPv4 B) IPv6 C) Both A and B D) Neither A nor B

C) Both A and B

The encapsulating security protocol offers ________. A) confidentiality B) authentication C) Both A and B D) Neither A nor B

C) Both A and B

To deliver an arriving packet to a destination host on a subnet connected to router, the router needs to know the destination host's ________ before the router can send the packet on to the destination host. A) IP address B) data link layer address C) Both A and B D) Neither A nor B

C) Both A and B

________ operates at the transport layer. A) TCP B) UDP C) Both A and B D) Neither A nor B

C) Both A and B

An IPv4 packet's protocol field value is 1. The data field contains a(n) ________ message. A) TCP B) UDP C) ICMP D) DNS

C) ICMP

The router selects a row in which the next-hop router is labeled local. The router will send the packet to the ________. A) default router B) local next-hop router C) destination host D) None of the above

C) destination host

Routers send packets out ________. A) ports B) connections C) interfaces D) plugs

C) interfaces

TCP messages are called ________. A) frames B) packets C) segments D) fragments

C) segments

The new version of Internet Protocol that is coming into use is IP version ________. A) 1 B) 4 C) 5 D) 6

D) 6

________ is used for supervisory messages at the internet layer. A) TCP B) DNS C) DHCP D) ICMP

D) ICMP

IP is made reliable through ________. A) echo and echo reply messages B) error advisement messages C) Both A and B D) Neither A nor B

D) Neither A nor B

TCP is ________. A) connectionless B) unreliable C) Both A and B D) Neither A nor B

D) Neither A nor B

In a routing table, Rows 47, 3,497, and 30,451 match the destination IP address of an arriving packet's IP address. Which row will the router look at last when trying to find matches? A) 1 B) 37 C) 30,451 D) The default row

D) The default row

In an IPv4 packet, the ________ field value tells the type of message contained in the IP packet's data field. A) data B) next-hop C) next-header D) protocol

D) protocol

The main benefit of IPv6 over IPv4 is ________. A) two more bits in the IP address B) two more bytes in the IP address C) the ability to have quality-of-service guarantees D) the ability to support more possible hosts

D) the ability to support more possible hosts

A router must use the ARP process ________. A) when a new router comes online B) when a router goes offline C) whenever it forwards an IP packet D) whenever it forwards an IP packet to a host that is not in its ARP cache

D) whenever it forwards an IP packet to a host that is not in its ARP cache

A router has to go through the ARP process each time it needs to send a packet to a destination host or to a next-hop router.

FALSE

A row in a routing table has the destination 10.8.0.0 and the mask /24. It is a match for 10.8.6.7.

FALSE

An autonomous system can freely select the exterior dynamic routing protocol it will use.

FALSE

Border router's main job is to connect different subnets in the same network.

FALSE

ICMP error advisement messages add reliability to IP.

FALSE

UDP is reliable.

FALSE

Converting networks to support IPv6 is relatively simple and inexpensive.

TRUE

If the ACK bit is set, the acknowledgment number field MUST have a value.

TRUE

In IPv6, routers usually only have to consider the hop-by-hop options extension header.

TRUE

The next-hop router in the default row is called the default router.

TRUE

The time to live field in IPv4 has the same basic function as the hop limit field in IPv6.

TRUE

To handle internetwork transmission control tasks that the IP protocol cannot handle, the IETF created TCP.

TRUE

When a network mask is applied to any IP address on the network, the result is the IP address' network part followed by zeros.

TRUE

When a packet arrives, the router should look for matches in ALL rows in the routing table.

TRUE

Which of the following segments is not acknowledged? A) FIN. B) RST. C) Both of the above are acknowledged. D) Neither A nor B is acknowledged. Answer: A

A) FIN

Which of the following is reliable? A) TCP. B) UDP. C) Both A and B D) Neither A nor B

A) TCP

In a network mask, the 1s correspond to the ________. A) network part B) subnet part C) host part D) None of the above

A) network part

Fragmentation is ________. A) very common B) suspicious because it is often used by hackers C) Both A and B D) Neither A nor B

B) suspicious because it is often used by hackers

65) If I simplify the address 2001:0000:0000:00fe:0000:0000:0000:cdef, I get ________. A) 2001:0000:0000:00fe::::cdef B) 2001:::00fe:0000:0000:0000:cdef C) 2001::00fe::::cdef D) 2001:::00fe::cdef

D) 2001:::00fe::cdef

In the IPv4 address 1.2.3.4, what is the network part? A) 1 B) 1.2 C) 1.3 D) We cannot say.

D) We cannot say.

In a routing table, a row is a route for a single IP address.

FALSE

Routers know the difference between network and subnet masks.

FALSE

The default row will never be selected as the best match row.

FALSE

Which of the following allows routers to check for errors in the header when a packet arrives? A) IPv4. B) IPv6. C) Both A and B D) Neither A nor B

A) IPv4

Dynamic ________ protocols allow routers to transmit routing table information to one another. A) routing B) transport C) synchronization D) None of the above

A) routing

When a router forwards incoming packets closer to their destination hosts, this is ________. A) routing B) switching C) bridging D) hopping

A) routing

An internal router only connects different IP ________. A) subnets B) networks C) Both A and B D) Neither A nor B

A) subnets

The use of options in IP is ________. A) very common B) suspicious because they are often used by hackers C) Both A and B D) Neither A nor B

B) suspicious because they are often used by hackers

The version number field in IPv6 has the value ________. A) 0001 B) 0100 C) 0101 D) None of the above

C) 0101

Which interior dynamic routing protocol is good for large internets? A) RIP. B) BGP. C) OSPF. D) Both A and C

C) OSPF