Troubleshooting Steps

Question 1

What are first 3 steps of the 7 step troubleshooting steps?

Answer 1

1) identify the problem (more accurately, the issue)
2) establish a theory of probably cause
3) test the theory to determine cause

Question 2

What are steps 4. 5. 6 and 7 of the 7 troubleshooting steps?

Answer 2

4) establish a plan to resolve the problem
5) implement the solution
6) Verify the solution has worked and no new issues appear. Fix those issues
7) Document findings, actions and outcomes

Question 3

Two devices using auto negotiation for duplex setting can still end up with duplex mismatch. TRUE or FALSE?

Answer 3

TRUE

Question 4

what is the default duplex setting on switches and hosts?

Answer 4

Auto

Question 5

what’s the command to check the MTU setting on a router interface?

Answer 5

show interface

Question 6

when checking switch port for potential issues, what 3 things should be checked?

Answer 6

1) Speed
2) Duplex setting
3) type of cable

Question 7

regarding issues with untrusted certificates, where are certificates stored on the local machine?

Answer 7

in the Trusted Root Certification Authorities Folder

Question 8

list 3 reasons that would cause an SSL certificate to be invalid?

Answer 8

1) CA not found in trusted root certification authorities folder
2) Certificate expired or presented before the validity period starts!
3) name doesn’t match

Question 9

incorrect time between machines will affect what 3 things?

Answer 9

1) Active Directory (5 mins difference will stop comms)
2) Certificates
3) Syslogs

Question 10

when checking for blocked tcp/udp ports what command is used?

Answer 10

netstat -a

Question 11

what’s the best way of controlling host-based firewall settings to prevent it causing access issues?

Answer 11

control them with a group policy

Question 12

what is the disadvantage of the bottom-up approach to establishing a cause?

Answer 12

you have to check a lot of things!

Question 13

if you can’t test a theory, and you’ve tried other theories, what do you then need to do?

Answer 13

escalate the problem

Question 14

What is a symptom of STP convergence issue?

Answer 14

network goes down for a min, then comes back up again and repeats

Question 15

Proxy ARP, missing routes, routing problems and routing loops would be escalated to which group?

Answer 15

the routing group

Question 16

routing loops will typically occur on what two protocols?

Answer 16

RIP and RIPv2

Question 17

when checking for routing loops/problems what can be easily be checked on the router?

Answer 17

the default route

Question 18

MTU blackhole occurrs under what two conditions

Answer 18

1) when the MTU on an intermediate network segment is smaller than the max packet size of the communicating hosts
2) if ICMP is disabled on the routers as they can’t communicate about an MTU mismatch issue

Question 19

When documenting the problem, what 5 things should you include?
(Des Violated Ruby Said Fanny)

Answer 19

Des Violated Ruby Said Fanny

1) description of issue
2) Version of OS/software/NIC
3) whether you could REPRODUCE the problem
4) Solutions tried
5) Final solution

Question 20

Apart from the IP address and subnet mask and gateway, when checking for IP configuration issues on a workstation, what 5 things are good to check?

Answer 20

1) DNS
2) DHCP
3) WINS
4) HOSTS
5) Registry

Question 21

when checking executable files troubleshooting potential software issue, what can you look out for?

Answer 21

lines that have been commented out and shouldn’t be like lines starting with # in the HOSTS file