217 Final Prep Flashcards
(93 cards)
1
Q
What are the 2 ways of creating extended ACLs?
Lecture 7b
A
Numbered Extended ACLs - Created using the access-list command
Named Extended ACLs - Created using the ip access-list extended command
2
Q
What are the 4 most popular protocols filtered through extended ACLs?
Lecture 7b
A
ICMP, IP, TCP, and UDP.
3
Q
What are some popular TCP port filtering options for Extended ACLs?
Lecture 7b
A
domain - DNS (Port 53)
ftp - File Transfer Protocol (port 21)
ftp-data - FTP Data connections (port 20)
pop3 - Post Office Protocol v3 (110)
smtp - Simple MAil Transport Protocol (25)
telnet - Telnet (23)
www - World Wide Web (HTTP, 80)
I don’t see Kevin testing us on anything other than the www (port 80), but I put the rest here just in case
4
Q
Describe the Basic syntax of the Extended ACL command(s)
Lecture 7b
A
access-list access-list-number [deny, permit, remark] protocol source source wildcard destination destination wildcard** eq** [operator /port]
for more info see, see slide 8
5
Q
What is the number range for extended ACLs?
Lecture 7b
A
100 to 199
6
Q
What is the purpose of NAT?
Lecture 9
A
NAT (Network Address Translation) is used to translate private IP addresses into public IP addresses
thanks to NAT, one public IPv4 address can be used for thousands of devices with private IP addresses.
NAT was put in place to prevent the exhaustion of IPv4 addresses. Without it, we would have run out of IPv4 before the year 2000.
7
Q
Where does NAT typically operate?
Lecture 9
A
NAT typically operates at the border of a stub network.
When a device inside of a stub wants to communicate with a device outside, the packet is forwarded to the border router which performs the NAT process.
8
Q
Define inside and outside NAT networks.
Lecture 9
A
the INSIDE network is the group of networks that is subject to translation. Any device inside of this specific network is considered an inside device.
The OUTSIDE network refers to all other networks. Any device outside of the network boundary is considered an outside device.
9
Q
What are the 4 types of NAT addresses?
Lecture 9
A
- Inside Local Addresses
- Inside Global Addresses
- Outside Local Addresses
- Outside Global Addresses
10
Q
Describe Inside Global and Inside Local NAT addresses.
Lecture 9
A
Inside Local Addresses are the SOURCE address from INSIDE the NAT network. (this would usualy be shown as a host PC inside of the network.)
Inside Global Addresses are teh source as seen from OUTSIDE the network. This is usually the INSIDE interface of the router on the Stub network.
11
Q
Describe Outside Global and Outside Local NAT addresses.
Lecture 9
A
Outside Global Addresses are the destination as seen from inside the network. This is usually the outside routers interface. This interface is the one that the Inside Local Host is trying to connect to.
The Outside Local Address is the destination as seen from outside the network. We will never actually know the outside local address.
12
Q
Name the 3 types of NAT.
Lecture 9
A
Static Network Address Translation (Static NAT). This is One-To-One address maping between logical and global addresses.
Dynamic Network Address Translation (dynamic NAT). Many-To-Many address mapping between local and global addresses.
Port Address Translation (PAT) Many-to-One Address mapping between local and global addresses. Also known as NAT Overload, this method utilizes port numbers to achieve address translation.
13
Q
What is the most common form of NAT?
Lecture 9
A
PAT or NAT Overload
14
Q
Compare and contrast NAT and PAT
Lecture 9
A
15
Q
List the advantages of NAT
Lecture 9
A
- Conserves the legally registered addressing scheme by allowing the privitization of intranets
- Conserves addresses through application port level multiplexing
- Increases flexibility of connections to the public network
- Allows the existing private IPv4 Address scheme to remain while allowing for easy transition to a new public addressing scheme
- Hides the IPv4 addresses for users and devices
16
Q
List the drawbacks of NAT
Lecture 9
A
- Increases forwarding delays
- End-to-end addressing is lost, and applications that require end to end addressing can’t be used with NAT
- End-to-End IPv4 traceability is lost, which can increase the difficulty of troubleshooting
- Complicates the use of tunneling protocols
- Can disrupt services that require the initiations of TCP connections or stateless protocols.
17
Q
What is NAT64?
Lecture 9
A
NAT64 is the process of providing protocol translation between IPv4 addresses and IPv6 addresses.
18
Q
What is the purpose of NAT64?
Lecture 9
A
Used to transparently provide access between IPv6 only networks and IPv4 only networks.
Can interconnect the 2 types of networks, but is not used as a form of private to globlal IPv6 translation.
Good as a temporary mechanism to assist with migrating a network from IPv4 to IPv6.
19
Q
Where can you find automation?
Lecture 10
A
Everywhere. From self-serve checkouts and automatic building environment controls, to autonomous vehicles, we encounter it everywhere.
I could see a Kevin question based off of this, so I included it.
20
Q
List some benefits of automation.
Lecture 10
A
- Machines don’t need breaks like humans do.
- Machines can provide a more uniform product with less human error
- Allows vast ammounts of data to be collected and analyzed to provide information to help guide events and processes.
- Using robots instead of humans in dangerous conditions such as mining, firefighting, and cleaning up industrial accidents can save human lives.
- Smart devices can alter their own behaviour to reduce energy usage.
21
Q
What is a smart device?
Lecture 10
A
Smart devices are devices that take a course of action based on an outside piece of information.
These devices incorporate smart technology to help govern their behavior. This can be a simple as a smart fridge, to as advanced as a self driving car.
Smart devices need to be programmed using network automation tools to be able to operate.
22
Q
What are data formats?
Lecture 10
A
Data formats are a way to store and exchange data in a structured format.
While many systems allow you to chose your own data format, and are compatable with multiple, some require specific data formats to be followed.
23
Q
Name some common data formats.
Lecture 10
A
- JSON (JavaScript Object Notation)
- eXtensible Markup Language (XML)
- YAML Ain’t Markup Language (YAML)
HTML is the starndard markup language for structuring web pages.
24
Q
What are the 3 specific characteristics that can help you identify data formats?
Lecture 10
A
- Syntax - Includes characteristics like which bracket types are used ([], {}, ()), indentation and white space rules, quotes, commas, etc.
- Object representation - How the language treats characters, strings, lists, and arrays
- Key/Value Pair Representation - Usually the key is on the left side identifiying or describing data. The value is on the right side and contains the data itself. This data can be a character, string, number, list, or any other type of data.
25
Describe the JSON data format.
| Lecture 10
JSON is a human readable dta format used by applications for storing, transfering and reading data.
Extremely popular, it used by many web services and APIs for providing public data.
Works well with most modern programming languages including Python.
26
List the syntax rules for JSON.
| Lecture 10
* Uses a hierarchical structure and contains nested values
* Uses {} to hold objects and [] to hold arrays.
* Written as key/value pairs.
* Keys MUST be strings contained inside " " marks.
* Values must be a valid JSON data type (string, number, array, Boolean, null, or another object)
* Key / value pairs are seperated by a colon.
* Multiple key/value pairs are seperated by commas.
* White space does not matter.
27
Describe the YAML data format
| Lecture 10
YAML is a human readable data format used by applications for storing, transferring and reading data.
* Minimalist format making it easy to both read and write
* Uses indentation to define its structure
* Can also use [] for lists and {} for maps
* Considered a superset of JSON
* A YAML parser can parse JSON - JSON Files are valid YAML files
28
Describe the XML Data format
| Lecture 10
Also a human readable data format.
* Is alike to HTML, which is the standardized markup language for creating web pages and web applications
* It is self-descriptive. It encloses data within a related set of tags data
* Unlike HTML, XML doesn't use predefined tags or document structure
* XML Objects are one or more key/value pairs, with the beginning tag used as the name of the key (example value )
29
Describe the XML Data format
| Lecture 10
Also a human readable data format.
* Is alike to HTML, which is the standardized markup language for creating web pages and web applications
* It is self-descriptive. It encloses data within a related set of tags data
* Unlike HTML, XML doesn't use predefined tags or document structure
* XML Objects are one or more key/value pairs, with the beginning tag used as the name of the key (example value )
30
Different data formats for reference
| Lecture 10
31
What are APIs?
| Lecture 10
APIs (Application Programming Interfaces) are software that allows other applications to access its data and services.
APIs act as a set of rules describing how one application can interact with another, and teh instructions to allow the interaction to occur.
An API is similar to a waiter in a resturant. The user (patron) makes an API request, the water then goes to the Applications (kitchen) and retrieves food (data) to return to the customer.
32
Describe Open, Internal, and Partner APIs.
| Lecture 10
Open (or public) APIs - Publicly available and able to be used without restrictions. Many API providers require the user to get a free token or key prior to use due to their public nature. This helps prevent overload from unnessecary requests.
Internal / Private APIs - Used by an organization or company to access data and services for internal use only. Example: Allowing only authorized sales staff to access internal sales data on their mobile devices.
Partner APIs - Used between a company and it's business partners to facilitate business between them. The partner must have a license or another form of permission to use the API .
33
What are the 4 types of web service APIs?
| Lecture 10
1. Simple Object Access Protocol (SOAP)
2. Representational State Transfer (REST)
3. eXtensible Markup Language - Remote Procedure Call (XML-RPC)
4. JavaScript Object Notation - Remote Procedure Call (JSON-RPC)
34
Describe the characterists of different web service APIs.
| Lecture 10 .
35
What is a REST API?
| Lecture 10
A REST API is an API that works on top of the HTTP protocol.
REST APIs define a set of functions developers can use to perform requests and receive responses via HTTP protocols such as GET and POST.
36
Describe the features of a RESTful API.
| Lecture 10
* Client-Server - The client handles the front end and teh server handles the back end. Either can be swapped out independently of the other.
* Stateless - No client data is stored on the server between requests. The session state is stored on the client.
* Cacheable - Clients can cache responses to improve performance.
37
What are the 4 defined aspects of a RESTful web service?
| Lecture 10
1. The base Uinform Resource Identifier (URI) for the web service.
2. The data format supported by the web service (Often JSON, YAML, or XML but could be any data format)
3. The Set of operations supported by the web service using HTTP methods
4. The API must be hypertext driven.
38
Match the common HTTP methods to their RESTful operations.
| Lecture 10
39
What are the 2 specializations associated with URIs?
| Lecture 10
1. Uniform Resource Name (URN) - Identifies only the namespace of the resource (webpage, document, image, etc.) without the reference protocol.
2. Uniform Resource Locator (URL) - Defines the network location of a specific resource. (HTTPS or HTTP URLs are typically used with web browsers)
40
What are the components of a URL?
| Lecture 10
1. Protocol/Scheme - HTTPS or other protocols such as FTP, SFTP, Mailto and NNTP
2. Hostname - www.example.com
3. Path and File name - /blah/blah.html
4. Fragment - #page155
## Footnote
The sample URL https://www.example.com/author/book.html#page155 : was used for this one
41
Describe the different parts of a RESTful request.
| Lecture 10
* API Server - This is the URL for the server that answers REST requests.
* Resources - Specifies the API that is being requested.
* Query - Specifies the data format and information the client is requesting from the API service.
* Format - Usually JSON
* Key - This key is used for authorization if required.
* PArameters - USed to send information pertaining to the request.
42
Describe some reasons why an API provider might require the use of a key.
| Lecture 10
* To authenticate the source to make sure they are authorized to be using the API
* To limit the amount of people using the API at a time
* To limit the number of requests per user
* To better capture and track data that is being requested by users
* To gather info on people using the API
43
What is SNMP?
| Lecture 10
Simple Network Management Protocol (SNMP) lets administrators manage nodes on an IP network.
With a network management station (NMS), network admin can use SNMP to monitor and manage network performance, find and solve problems, and perform queries for statistics.
SNMP is not typically used for configuration due to security concerns and difficult implementations.
You can also use tools and APIs to automate configurations.
44
What are Configuration Management Tools?
| Lecture 10
Configuration management tools make use of RESTful API requests to automate tasks and are scaliable across thousands of devices.
45
What can be automated using configuration management tools?
| Lecture 10
* Software and Version Control
* Device Attribute configurations (names, addressing, security, etc)
* Protocol Configurations
* ACL configurations
* ...and more!
46
Describe how automation and orchestration work in configuration management tools.
| Lecture 10
Automation is when a tool automatically performs a task on a system.
Orchestration is the arranging of the automated tasks that results in coordinate process or workflow.
47
Name the tools Kevin names in the lecture slides.
| Lecture 10
* Ansible
* Chef
* Puppet
* SaltStack
48
What are the main goals of configuration management tools?
| Lecture 10
The main goal of configuration management tools is to reduce the complexity and time involved in configuring and maintaining large scale network infrastructure.
49
What is IBN?
| Lecture 10
IBN (Intent-Based Networking) is the new industry model for the next generation of networking.
IBN builds on Software - Defined Networking to transform a hardware-centric and manual approach to designing and maintaining networks into a more automated and software based model.
50
Name and Describe the 3 essential functions of IBN
| Lecture 10
1. Translation - Enables the network adminstrator to express the expected networking behavior that would best support the business intent
2. Activation - Installs these established policies into the physical and virtual network infrastructure using networkwide automation
3. Assurance - In order to continuously check that the expressed intent is honored by the network, the assurance function maintains a continuous validation and verification loop.
51
What is Cisco DNA?
| Lecture 10
Cisco DNA (Digital Network Architecture) is a data gathering software. Data is taken from sources sucha as devices and applications to provide a database of information.
This information is utilized to make sure networks are performing optimally and in accordance with business intent and policies.
52
List and describe some Cisco DNA Solutions
| Lecture 10
* SD-Access - Uses a single network fabric across LAN and WLAN to create a highly secure user experience.
* SD-WAN - Simplifies and accellerates the delivery of secure, flexible and rich WAN services.
* Cisco DNA Assurance - Applies Advanced analytics and machine learning to improve performance and issue resolution.
* Cisco DNA Security - Provides increased granular control to enforce policy and contain threats across a network.
| For more info see Lecture 10, Slide 50-51
53
What is CDP?
| Lecture 11
CDP (Cisco Discovery Protocol) is a proprietary layer 2 protocol designed to gather information about Cisco devices that share data links.
54
How does CDP operate?
| Lecture 11
* CDP is media and protocol independent and runs on all Cisco devices
* The CDP active device sends periodic CPD advertisements to all connected devices. These advertisements share information about the type, name, number and interfaces of conected devices.
* Information gathered is used to help build a logical topology when documentation is missing.
55
How is CDP configured by default?
| Lecture 11
* CDP is enabled by default on cisco devices.
* To disable CDP on an interface, the **no cdp enable **command needs to be inputted.
* To enable CDP globally, the** cdp run **command must be used on the device in global config mode.
56
What is LLDP?
| Lecture 11
LLDP (Link Layer Discovery Protocol) is a vendor neutral neighbor discovery protocol that works simliarly to CDP.
LLDP works with network devices, and operates by advertising its identity and capabilities to other devices. Information is received from a physically connected Layer 2 device.
57
What is the purpose of NTP?
| Lecture 11
NTP (Network Time Protocol) allows all routers on the network to synchronize their time settings with an NTP server, which provides consistent date and time settings across the devices.
NTP can be set up to synchronize to a private master clock, or it can synchronize to a publically available NTP Server on the internet.
58
What port does NTP use?
| Lecture 11
NTP uses UDP port 123
(easy to remember, NTP 123 its like a poem)
59
How does NTP operate?
| Lecture 11
NTP networks use a hierarchical system of time sources. Each level in the system is called a stratum. The stratum level is defined by the number of hop counts it takes from the authoritative source.
The max hop count is 15. 16 is the lowest level stratum, and indicates that the device is unsynchronized.
60
Describe the basic function of NTP Stratum levels.
| Lecture 11
* Stratum 0 - Top level of the hierarchy. Authoritative time source. These devices are considered high-precision timekeeping devices which are assumed to be accurate with little or no delay. Think atomic clocks, GPS, or radio clocks.
* Stratum 1 - Devices that are directly connected to authoritative time sources. Act as the primary network time standard.
* Stratum 2 and lower - Servers that are connected to stratum 1 devices through network connections. The smaller the number teh closer to the sourc.
61
Describe SNMP
| Lecture 11
SNMP (Simple Network Management Protocol) was developed to allow administrators to manage nodes an IP network.
62
What are the 3 elements of SNMP?
| Lecture 11
1. The SNMP Manager - Collects information from an SNMP agent by using the "get" action, and can change configurations using the "set" action.
2. The SNMP Agents - Forwards information directly to a manager by using "traps"
3. The Management Information Base (MIB) - Store data and operational statistics that are meant to be available to authenticated users. The agent is responsible for providing access to the MIB.
63
What are SNMP Agent Traps?
| Lecture 11
Traps are unsolicited messages alerting the SNMP manager to a condition or event on the network.
Trap directed notifications reduce network and agent resources by eliminating the need for some of SNMP's polling requests.
64
Describe the different versions of SNMP
| Lecture 11
* SNMPv1 - Legacy standard. Utilizes a simple community-string based authentication method. Not used anymore
* SNMPv2c - Uses a simple community-string based authentication method as well. Provides for bulk retrieval options, and more detailed error messaging.
* SNMPv3 - Current standard. Uses username authentication, provides data protection through DES, 3DES, or AES encryption.
65
What is syslog, and how is it used?
| Lecture 11
Syslog is used for message logging inside of network devices. Allows for the separation of the software that generates messages, the software that stores them, and the software that reports and analyzes them.
66
Describe the primary characteristics of Syslog.
| Lecture 11
The main syslog characteristics include:
* Describing a standard and protocol
* Uses UDP port 514, but could be changed to TCP depending on the software used
* Sending event notification messages across IP networks to event message collectors
* Routers, Switches, Servers, and Firewalls all support syslog.
67
Describe the 3 primary functions of syslog.
| Lecture 11
* The ability to gather logging information for monitoring and troubleshooting
* The ability to select the type of logging information that has been captured
* The ability to specify the destinations of captured syslog messages
68
Explain some of the different ways that Syslog can operate.
| Lecture 11
* Syslog messages may be sent to an interanl buffer and are only accessible by the administrator using the CLI.
* Syslog messages may be sent to a console or a terminal.
* syslog messages may be sent across the network to an external syslog server.
The way the syslog operates is based on specific device configurations.
69
What does each syslog severity level mean?
| Lecture 11
When it comes to syslog, the SMALLER the number, the MORE critical the alarm is.
* Emergency level 0 - Warning Level 4 = Error messages about hardware and sofware malfunctions that are affecting functionality
* Level 5 - Normal events and system restart messages
* Level 6 - Normal message that does not affect functionality.
* Level 7 - Output generated from various Debug commands.
## Footnote
flash card 69 (nice)
70
What generates the most common Syslog reports?
| Lecture 11
* IP
* OSPF
* IPsec
* Interface IP
71
Describe the basic format for Cisco IOS syslog messages.
| Lecture 11
72
Describe the purpose of using a TFTP server.
| Lecture 11
TFTP servers store Cisco IOS software images and configuration files.
Keeping a backup is important in case the system image on a router becomes corrupted.
Using a network TFTP server allows for image and configuration uploads and downloads over a network. Can be a router, workstation, or a host system.
73
Describe the purpose of using a TFTP server.
| Lecture 11
TFTP servers store Cisco IOS software images and configuration files.
Keeping a backup is important in case the system image on a router becomes corrupted.
Using a network TFTP server allows for image and configuration uploads and downloads over a network. Can be a router, workstation, or a host system.
74
What are the 3 steps of backing up an IOS image to a TFTP server?
| Lecture 11
1. Ping the TFTP server to verify connectivity
2. Verify the image size in flash memory using the show** flash0** command.
3. Copy the image to the TFTP server using the command** copy ***source-url destination-url*
75
What are the 6 steps of recovering a Router password?
| Lecture 11
1. Enter the ROMMON mode (kind of like entering the BIOS when you reboot your PC)
2. Change the configuration register
3. Copy the startup-config to the running-config
4. Change the password
5. Save the running-config as the new startup-config
6. Reload the device.
76
Describe the components of network documentation.
| Lecture 12
Accurate and network documentation is required to effectively monitor and troubleshoot networks.
Network documentation should include:
* Physical and Logical topology diargrams
* Device documentation that records all important device information
* Network performance baseline documentation
77
What is the purpose of network baselines?
| LEcture 12
A network baseline is to establish normal network performance to determine the personality of a network under normal conditions
Baseline data provides insight into whether the current network design can meet business requirements.
Baselines can also reveal areas of congestion or other areas in a network that may be underutilized.
78
What are the steps to defining network baselines?
| LEcture 12
1. Determine what type(s) of data to collect. - Start simple and fine tune along the way.
2. Identify devices and ports of interest - Use topologies to identify devices to monitor
3. Determine a baseline duratoin - When analyzing a network, determine how long you want to monitor the network data, and how often a baseline is recorded.
79
Describe the detailed seven-step troubleshooting process.
| Lecture 12
**1. Define the problem** - Verify there is a problem and properly define what it is
**2. Gather Information** - Targets are identified, accessed and information on them is gathered.
**3. Analyze Information** - Identify possible causes using network documentation, baselines, knowledge bases, and peers.
**4. Eliminate possible causes** - Progressively eliminate possible causes to eventually determine the most probable cause
**5. Propose Hypothesis** - When most probable cause has been identified, a solution is formulated
**6. Test Hypothesis** - Assess the urgency of the problem, create a rollback plan, impliment the solution and verify the outcome.
**7. Solve the problem** - When solved, inform all involved and document the cause and solution for the future
80
Name and describe some structured troubleshooting methods.
| Lecture 12
* **Bottom Up** - Good to use when the problem is suspected to be a physical one. Start with the physical layer and work up.
* **Top-Down** - Used for simpler problems, or when the problem seems to be a software issue
* **Divide and Conquer** - Start at Layer 3 and test in both directions from the layer.
* **Follow the Path** - Used to discover the traffic path from source to destination to reduce the scope of the troubleshooting
* **Substitution** - Physically swap a problematic device with a known working one.
* **Comparison** - Compare a nonoperational element of a problem with a working one.
* **Educated Guess** - Success varies depending on the troubleshooting experience and ability.
81
Describe some common troubleshooting tools.
| Lecture 12
* Network Management System tools - NEtwork software tools that can be used to investigae and correct network problems.
* Knowledge bases - Online networks and vendor based knowledge bases are indispensable sources of information.
* Baselining tools - Help with common documentation tasks such as networking diagrams, hardware documentation, and network software updates.
82
Name some hardware troubleshooting tools.
| Lecture 12
* Digital multimeters
* Cable Testers
* Cable Analyzers
* Portable network analyzers
* Cisco Prime NAM
83
Describe some common physical layer symptoms, and their causes.
| Lecture 12
84
Describe some physical layer problem causes.
| Lecture 12
85
Describe some symptoms of data link layer problems
| Lecture 12
86
Describe some data link layer problem causes
| Lecture 12
87
List common symptoms of network layer problems
88
List some network layer problem causes
| Lecture 12
89
List some common ACL misconfiguration problems.
| Lecture 12
90
List some common interoperability issues with DHCP, NAT, and DNS
| Lecture 12
91
List some application layer protocols that should be checked when troubleshooting.
| Lecture 12
92
List the steps to performing a bottom-up troubleshoot with no end-to-end connectivity.
| Lecture 12
1. Check Physical connectivity at the point where network communication stops (perform a trace route)
2. Check for duplex mismatches
3. Check the data link and network layer addressing on the local network
4. Verify the device has the correct default gateway
5. Ensure that devices are determining the correct path from the source to the destination
6. Verify the transport layer is functioning properly
7. Verify there are no ACLs blocking traffic
8. Ensure taht DNS settings are correct (should be the top of the list lol)
93
What are the 2 most common tools used when verifying an end-to-end connectivity problem?
| Lecture 12
Ping and traceroute/tracert
