Chapter 3: How Data is Transported over Networks

Which protocol's header would a Layer 4 device read and process?

TCP

What number does a host use to identify the application involved in a transmission?

Port number

What field in a TCP segment is used to determine if an arriving data unit exactly matches the data unit sent by the source?
Source port

Checksum

At which OSI layer does IP operate?

Network layer

Which OSI layer is responsible for directing data from one LAN to another?

Network layer

What kind of route is created when a network administrator configures a router to use a specific path between nodes?

Static route

When a router can't determine a path to a message's destination, where does it send the message?

Gateway of last resort

A routing protocol's reliability and priority are rated by what measurement?

AD

Which routing protocol does an exterior router use to collect data to build its routing tables?

BGP

When messages to a remote Web server are being lost for no apparent reason and you suspect the problem might be a path MTU black hole, which TCP/IP utility can you use to diagnose the problem?

ping

What is NOT one of the three characteristics of TCP in its role as a reliable delivery protocol??

Framing

?What field in an IPv4 packet informs routers the level of precedence they should apply when processing an incoming packet?

?Differentiated Services (DiffServ)

A modern ASN consists of how many bits?

?32

?What netstat command option lists only current connections, including IP addresses and port numbers?

?-n

By default, the pathping command sends how many pings per hop??

?100

?Which network routing protocol is a path vector protocol that sends updates between routers using TCP?

?BGP

What protocol replaces ARP, IGMP, and ICMPv4 on IPv6 based networks??

ICMPv6

At what layer of the OSI model would a TCP or UDP header be added to a payload?

?Layer 4

In a TCP segment, what field indicates how many bytes the sender can issue to a receiver while acknowledgement for the segment is outstanding??

?sliding window

Which of the following is not a task handled by a router?

?A router forwards broadcasts over the network.

The IP connectionless protocol relies on what other protocol to guarantee delivery of data?

?TCP

?What command can be used on a Cisco router to view the routing table?

?show ip route

What parameter can be combined with the traceroute command to instruct it to use ICMP echo requests instead of UDP datagrams??

?-I

What TCP field below allows the receiving node to determine whether a TCP segment is corrupted during transmission??

?checksum

What happens when a router receives a packet with a TTL of 0??

?The router drops the packet and sends an ICMP TTL expired message back to the host.

In IPv6, what field is used to indicate what sequence of packets from one source to one or multiple destinations a packet belongs to??

?flow label

What IPv4 protocol handles multicasting for tasks such as videoconferencing or teleconferencing??

IGMP?

When viewing the routing table on a UNIX system, what flag indicates if a route is a usable route??

?U

What routing protocol criteria is defined as the time it takes to recognize a best path change in the event of a network outage?

?convergence time

What type of routing protocol enables routers to communicate beyond neighboring routers, allowing each router to create a map of an entire network??

?link state