Module 8

Question 1

The 1/2 split method

Answer 1

divide & conquer. Divide the circuit or topology in 1/2 & test. This is continued to be done until the problem component is found.

Question 2

Troubleshooting questions

Answer 2

1. How widespread is the issue? (users affected)
2. were there any recent changes?
3. Are there any problems w/ power?
4. What layers are involved?

Question 3

Troubleshooting Steps

Answer 3

1. Don’t Panic
2. Get the right resources engaged.
3. What was the last thing that changed?
4. Get the data that you can.
5. Learn when 2 escalate.
6. Was this a process problem? How do we avoid this in the future?

Question 4

Implementation Considerations

Answer 4

1. Small Office LAN deployment.
2. List of requirements
3. Device types & requirements
4. Equipment limitation (space growth)
5. Compabality Requirements (works w/ other devices/services)
6. Wired/Wireless Considerations.
7. Security.

Question 5

Network Operation Center - NOC

Answer 5

a place where network admin monitors & manages the network. Contains systems 2 visualize health of the network in real-time & provides automated alerting at any time. It is the focal point 4 troubleshooting & updating network devices i.e (router, switch, firewall, etc.)

Question 6

Network Monitoring

Answer 6

1. Ping Monitoring
2. SNMP Monitoring & Graphing
3. Netflow & SFlow
4. Server Software ( Solarwinds)
5. Syslogs (System logs)

Question 7

Configuration Management

Answer 7

1. Manual Configuration backups via CLI.

2. Automated backups

Question 8

Authentication, Authorization, Accounting - AAA

Answer 8

Authentication - is user valid
Authorization - what is the user authorized to do
Accounting - keep track of what the user has done.

Question 9

Terminal Access Controller Access Control System - TACACS

Answer 9

a family of related protocols handling remote authentication and services for network access through a centralized server.

Question 10

Remote Authentication Dial-in User Service - RADIUS

Answer 10

is a networking protocol, operating on ports 1812 & 1813, that provides centralized AAA management for users who connect and use network services.

Question 11

System Log

Answer 11

entries made 4 everything that happens on network devices. A log can be stored in a device itself or a logging server.

Question 12

Syslogging Locations

Answer 12

1. Console
2. VTY lines
3. Logging buffer
4. External Syslog Server

Question 13

Syslogging Severity Levels

Answer 13

0 = Emergency
1 = Alert
2 = Critical 
3 = Errors
4 = Warnings
5 = Notification
6 = Informational 
7 = Debugging

Question 14

Debugging

Answer 14

is the process of finding and resolving bugs within computer programs, software, or systems in real-time. Uses “terminal monitor” if telnet/ssh to console & “ debug all” to clear debugs.

Question 15

Business Continuity

Answer 15

plan 2 ensure an organization has a speedy recovery & can continue 2 operate after a disruption.

Question 16

Disaster Recovery

Answer 16

a documented process 2 recover & protect a business IT infrastructure in the event of a natural or man-made disaster.

Question 17

Product Authorization keys

Answer 17

needed 2 claim licenses via Cisco licensing portal.

Question 18

IPconfig

Answer 18

displays IP @ info of a host. Also use 2 obtain MAC @.

Question 19

Ping

Answer 19

ICMP responsible for 4 ping, works @ L3.

Question 20

Traceroute - Tracert

Answer 20

traces out the hop by hop route 2 an IP endpoint.

Question 21

Pathping

Answer 21

similar 2 tracert includes local hop & exclude latency on 1st trace. Perform statistics on each hop 2 track lost vs sent packets & latency at each hop.

Question 22

Nslookup

Answer 22

perform a name server lookup using DNS. Can also perform a reverse lookup IP @ to hostname.

Question 23

Netstat

Answer 23

(-a, -b, -n, -o, -r) displays active L4 TCP /UDP sessions on a host.

Question 24

Nbstat

Answer 24

windows only display NETBIOS over TCP/IP statistics

Question 25

Remote Desktop Access

Answer 25

allows 4 logging into a desktop from a remote location.

Question 26

Terminal Emulation/Consoles

Answer 26

provides a GUI 4 connecting 2 local consoles & uses protocols TELENT/SSH/

Question 27

Protocol Analyzer

Answer 27

aka sniffer captures traffic from a NIC & dissects the info inside the frames & packets.

Question 28

BGP Looking Glass Sites

Answer 28

allows 4 BGP route & ASN lookups on the public internet.

Question 29

CCNA troubleshooting steps

Answer 29

1. Problem Isolation & Documentation 2. Resolves or Escalate 3. Verify or Monitor

Question 30

CompTIA troubleshooting steps

Answer 30

1. Identify problem 2. Establish a theory of cause 3. Test the theory 4. Establish a resolution 5. Implement the solution 6. Verify & Preventive measures 7. Document all findings

Question 31

Techniques & tools

Answer 31

1. check/changes cables ( check L1 1st) 2. test connectivity & trace the path 2 a destination. 3. Use 1/2 split method 4. Use configuration comparator 5. Change equipment hardware, line cards, or other components

Question 32

Basic Troubleshooting Steps

Answer 32

1. Incorrect interface configurations 2. Static routes w/ incorrect network, mask, or next stop 3. Network statement incorrect in routing protocol.

Question 33

Troubleshooting RIP

Answer 33

1. Incorrect network statement. 2. Passive interface configured in the wrong spot 3. Auto-summarization is enabled 4. Hop count limitation reached 916) 5. RIP version mismatch. 6. Authentication parameter mismatch

Question 34

Basic Cable Checks

Answer 34

1. Visual link light on both sides of connection 2. Test entire cable run 3. Check termination points 4. Check & test the patch cable involved ( no bends/bad usage)

Question 35

WAN circuit

Answer 35

if it fails causes a loss of connectivity in a large # of users.