Chapter 3

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

A router forwards broadcasts over the network.

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

100

Autonomous System Number (ASN) consists of _____ bits.

32

A router that directs data between networks within the same autonomous system.

gateway router

A _______ joins two or more networks and passes packets from one network to another.​

router

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

AD (Administrative Distance)

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

BGP (Border Gateway Protocol)

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

Checksum

List three characteristics of TCP in its role as a reliable delivery protocol

Connection-oriented Protocol, Sequencing and checksums, and flow control

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

Differentiated Services (DiffServ)

Describe dynamic ARP table entries.

Dynamic ARP table entries are created when a client makes an ARP request that could not be satisfied by data already in the ARP table.

What is the difference between static and dynamic routing?

Dynamic Routing- Automatically calculates the best patch between two networks and accumulates this information in the routing table Static Routing- Is a technique in which a network admin configures a routing table to direct messages along specific paths between networks.

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

Framing

Examples of routing metrics used by routers to determine the best of various available routing paths.

Hop count, latency, and routing cost

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

ICMPv6

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

IGMP

Which two protocols are essential to IPv4 networks, but whose functions are performed by ICMPv6 on IPv6 networks?

IGMP (Internet Group Management Protocol) and ARP (Address Resolution Protocol)

Which has better security, IPv4 or IPv6, and why?

IPv6, because it has built in security

Direct data between networks within the same autonomous system.

Interior Router

Which layers of the OSI model are all routers able to interpret?

Layer 3 and 4

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

Layer 4

The largest IP packet size in bytes allowable by routers in a path without fragmentation and excluding the frame size.​

MTU (maximum transmission unit)

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

Port number

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

Manually modifying a routing table can cause messages to get stuck hopping between a limited number of routers. What is this problem called?

routing loop

What database does a router consult before determining the most efficient path for delivering a message?

routing table

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

show ip route

A number indicating a protocol's reliability, with lower values being given higher priority. This assignment can be changed by a network administrator when one protocol should take precedence over a previously higher-rated protocol on a network.​

AD (administrative distance)

A globally unique number that identifies an autonomous system. ASNs work similarly to IP addresses that identify individual nodes on a network. Each ASN now consists of 32 bits instead of 16 bits, and they are assigned by IANA.​

Autonomous system number

List three interior gateway protocols (IGPs).

RIP, RIPv2, OSPF

Describe static ARP table entries.

Static ARP table entries are those that someone has entered manually using the ARP utility.

Which of the following are types of entries an ARP table contains?

Static and Dynamic

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

Static route

The IP connection-less protocol relies on what other protocol to guarantee delivery of data?

TCP

Direct data between autonomous systems.

Exterior Router

True or False: UDP provides error checking, but not sequencing.​

False

True or false: UDP provides error checking, but not sequencing.​

False

What four functions do all routers perform?

connect different LAN's, find best route, select alternative route if one is down, and interpret layer 3 and 4 addressing and other information

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

At which OSI layer do routers operate?

Network layer (layer 3)

At which OSI layer does IP operate?

Network layer (layer 3)

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

Network layer (layer 3)

A router that directs data between networks within the same autonomous system.​

gateway router

A router that connects an autonomous system with an outside network—for example, the router that connects a business to its ISP.

interior router

The delay between the transmission of a signal and its receipt.

latency

What kind of web site allows you to remotely collect network routing information back to your actual location?

looking glass sites

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

A repeated trial message transmitted by the tracert and traceroute utilities to trigger routers along a route to return specific information about the route.

probe

Properties of a route used by routing protocols to determine the best path to a destination when various paths are available. Routing metrics may be calculated using any of several variables, including hop count, bandwidth, delay, MTU, cost, and reliability.

routing metric

What process is used to establish a TCP connection?

Three-way handshake

Connect an autonomous system with an outside network.

Border Router

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

TCP

This netstat command option lists only current connections, including IP addresses and port numbers.

-n

Which of the following is not a task handled by a router? A. ​A router forwards broadcasts over the network. B. A router can reroute traffic if the path of first choice is down but a second path is available. C. ​A router can interpret Layer 3 and often Layer 4 addressing. D. ​A router can connect dissimilar networks.

A

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

BGP (Border Gateway Protocol)

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

Checksum

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

Default route

The TCP ___________________ is performed before TCP transmits the actual data.​

Three-way handshake

True or False: On IPv4 networks, IGMP operates at the Network layer of the OSI model to manage multicasting.

True

True or false: IP is an unreliable, connection-less protocol.​

True

True or false: On IPv4 networks, IGMP operates at the Network layer of the OSI model to manage multicasting.​

True

___'s lack of sophistication makes it more efficient than ​TCP.

UDP