Intro to Troubleshooting- Week 6

Question 1

ICMP

Answer 1

internet control message protocol- mainly used by a router or remote host to communicate why a transmission has failed back to the original host

Question 2

ICMP type

Answer 2

8 bits, specifies what type of message is being sent

Question 3

ICMP code

Answer 3

indicates a more specific reason for the message`

Question 4

ICMP checksum

Answer 4

like all the other checksums

Question 5

ICMP rest of header

Answer 5

optionally used by some of the specific types and codes to send more data

Question 6

ICMP data payload

Answer 6

contains the entire IP header and the first 8 bytes of the data payload section of the offending packet

Question 7

PING

Answer 7

a special type of ICMP

Question 8

PING echo request

Answer 8

used to determine the state of a connection

Question 9

The ping utility sends what message type?

Answer 9

an echo request ICMP message type

Question 10

traceroute

Answer 10

lets you discover paths between 2 nodes and gives you info about each hop along the way

Question 11

what does traceroute on linux and mac send?

Answer 11

UDP packets to very high port numbers

Question 12

tracert

Answer 12

traceroute on windows- sends an ICMP echo request

Question 13

mtr

Answer 13

long-running traceroute on linux and mac

Question 14

pathping

Answer 14

long-running traceroute on Microsoft

Question 15

nc

Answer 15

netcat- mac and linux- tests port connectivity

Question 16

what are the arguments for nc?

Answer 16

nc + a host + a port

Question 17

what will nc -v -z +x +x tell you?

Answer 17

if a connection to a port is possible or not

Question 18

which text command tells you the IP address for a host name?

Answer 18

nslookup + hostname

Question 19

which text command do you enter if you want to know the name resolutions for a server instead of the default server name?

Answer 19

nslookup [enter]

> [server + address of server]

Question 20

which text command do you enter if you want to know the record name, other than the A record, for a host?

Answer 20

nslookup [enter]

> [set type= MX +hostname] (or AAAA, or text)

Question 21

which text command do you enter if you want to know information about the packet sent to the server and the resulting answer.

Answer 21

nslookup [enter]

>[set debug + hostname]

Question 22

What IPs does google’s public IP run on?

Answer 22

8.8.8.8 and 8.8.4.4

Question 23

How are public servers useful for troubleshooting?

Answer 23

you can test general internet connectivity by sending a ping request to one.

Question 24

what IPs does level 3 comm’s public domain use?

Answer 24

4.2.2.1- 4.2.2.6

Question 25

registrar

Answer 25

an organization that’s responsible for assigning individual domain names to other organizations or individuals

Question 26

host file

Answer 26

a flat file that contains, on each line, a network address followed by the host name it can be referred to as

Question 27

What is the loopback address for IPv4?

Answer 27

127.0.0.1

Question 28

What does sending traffic to the loopback address do?

Answer 28

Sending traffic to a loop back address bypasses all network infrastructure itself and traffic like that never leaves the node.

Question 29

Why should host files no longer be used today?

Answer 29

are a popular way for computer viruses to disrupt and redirect users’ traffic.

Question 30

PaaS

Answer 30

Platform as a service- the most common platform. gives programmers all the tools they need to deploy, administer and maintain a Web application.

Question 31

SaaS

Answer 31

software as a service. a way of licensing the use of software to others while keeping that software centrally hosted and managed.

Question 32

IaaS

Answer 32

infrastructure as a service. abstracts away the physical infrastructure. client responsible for everything else.

Question 33

what are the requirements for virtualization for a client’s physical machine?

Answer 33

hypervisor support, enough RAM for each VM, and storage space.

Question 34

resource pooling

Answer 34

Any time you can consolidate systems’ physical and time resources

Question 35

measured service

Answer 35

when you are charged based on the traffic that goes in and out of your Web application or for the time that every single one of your virtualized servers is running rather than a fixed monthly or yearly fee.

Question 36

metered service

Answer 36

when you’re charged by the amount of processing resources used, such as CPU usage so you pay for what parts of the hardware you use, rather than a more general fee for all the hardware of a system.