Build a Small Network + Networking Troubleshooting Study Guide

Network documentation

Physical and logical topology

Device inventory

List of devices that use or comprise the network

Budget

Itemized IT budget, including fiscal year equipment purchasing budget

Traffic analysis

Protocols, applications, and services and their respective traffic requirements should be documented

What are type methods that you can use to determine the traffic flow patterns?

Capture traffic during peak utilization times to get a good representation of the different traffic types. Perform the capture on different network segments and devices as some traffic will be local to a particular segment

What are some built-in tools that help network administrator be aware of how network use is changing?

Task Manager, Event Viewer, and Data Usage tools

What tools can help capture a "snapshot" of information?

OS and OS Version, CPU utilization, RAM utilization, Drive utilization, Non-Network applications, and Network applications

What does "!" mean in IOS Ping Indicators?

indicates successful receipt of an echo reply message, It validates a Layer 3 connection between source and destination

What does "." mean in IOS Ping Indicators?

time expired waiting for an echo reply message., indicates a connectivity problem occurred somewhere along the path.

What does "U" mean in IOS Ping Indicators?

Indicates a router along the path respond with an ICMP Type 3 "destination unreachable" error message., Possible reasons include the router does not know the direction to the destination network or it could not find the host on the destination network.

The Cisco IOS offers an "extended" mode of the ping command. This mode enables the user to

create a special type of pings by adjusting parameters related to the command operation.

Trace requests to the next hop timed out as indicated by the

asterisk (*), meaning that the next hop router did not respond.

The timed out requests indicate that there is a failure in the internetwork beyond the LAN, or that these routers have been configured to

not respond to echo requests used in the trace.

The Cisco IOS extended traceroute option enables the user to

create a special type of trace by adjusting parameters related to the command operation

there is also an extended traceroute command. It allows the administrator to adjust parameters related to the command operation. This is helpful in locating the problem when troubleshooting

routing loops, determining the exact next-hop router, or determining where packets are getting dropped or denied by a router or firewall.

One of the most effective tools for monitoring and troubleshooting network performance is to establish a

network baseline

The Cisco Discovery Protocol (CDP) is a

Cisco proprietary protocol that runs at the data link layer

What information is provided by CDP?

Device identifiers, Address list, Port identifiers, Capacilit list, and Platform.

True or False: When a Cisco device boots, CDP starts by default. CDP automatically discovers neighboring Cisco devices running CDP, regardless of which Layer 3 protocol or suites are running. CDP exchanges hardware and software device information with its directly connected CDP neighbors.

True

What command is used to disable CDP globally?

no cdp run

What is the command to disable CDP on an interface?

no cdp enable

What is the command to show cdp details?

show cdp neighbors details

True or False: CDP is, it can also be a security risk because it can provide useful network infrastructure information to threat actors.

True

What are the 6 steps when doing networking troubleshooting?

Identify the Problem, Establish a Theory of Probable Cause, Test the Theory to Determine Cause, Establish a Plan of Action and Implement the Solution, Verify Solution and Implement Preventive Measures, Document Findings, Actions, and Outcome.

True or False: In some situations, it may not be possible to resolve the problem immediately. A problem should be escalated when it requires a manager decision, some specific expertise, or network access level unavailable to the troubleshooting technician.

True

True or False: All debug commands are entered in global EXEC mode?

False

The IOS debug command allows the administrator to

display these messages in real-time for analysis. It is a very important tool for monitoring events on a Cisco IOS device.

Debugging output is assigned high priority in the CPU process and

it can render the system unusable.

Locally connections

Local connections (i.e., console connection) require physical access to the router or switch console port using a rollover cable.

Remotely connections

Remote connections require the use of Telnet or SSH to establish a connection to an IP configured device