NYC College of Technology

CST3607: Interconnectivity (Spring 2018)

Green Bullet Announcements
Green Bullet Assignment Requirements
Green Bullet Required Texts
Green Bullet Class Notes & Assignments : February, March, April, May
Green Bullet Recommended Web Sites and Books[ NoScript ] uBlock Origin
Green Bullet Log into BlackboardExternal Link
Green Bullet Cisco IOS and Router Command Reference
Green Bullet Bit Patterns of Often Used Subnet Mask Values (pdf)
Green Bullet OSI Reference Model (pdf)
Green Bullet IP Address Conversions : Decimal to Base-256 / Base-256 to Decimal


Assignment #5, Due Tues. 5/8/2018

Final Exam: Tuesday: May 22, 2018

Notify your family and friends not to make any travel plans for you, as you will not be able to take the final exam before class on May 22, 2018.

Exam-03: Thurs. April 26, 2018

Exam-02: Thurs. March 29, 2018

Assignment #4, Due Tues. 3/13/2018

Exam-01: Thurs. 3/8/2018

Assignment #3: Due Tues. 3/6/2018

Quiz #1: Subnetting: Thurs. 3/1/2018

Assignment #2: Due Tues. 2/27/2018

Assignment #1: Due Thurs. 2/22/2018

Important note about sending E-Mail to Me
  • Only use the e-mail address I gave you in class to communicate with me.
  • Do not use my address and do not e-mail me via Blackboard.


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Required for all Assignments

  • Make sure that your full name is neatly written on your assignment.
  • Submit a typed hardcopy at the beginning of class.
  • If you use the RTF or DocX template I supply, type your answers in the table below each question.
    • If you do not use the template I supply, make sure your answers stand out from the text of the question. i.e. bold or underlined, not both.
  • Do not double space.
  • Do not type your answers in all uppercase.
  • Print out your assignments before you come to class.
    Do not rely on the printer or network in our classroom to be available or functional.
  • Make sure that the correct assignment number and chapter are on your paper. Be mindful that the assignment number is not always the same as the chapter number.
  • E-mail your assignment only if you are going to be absent, and at least 2 hours before class starts, on the day that the assignment is due. This should ensure that I receive your assignment before the start of class.
  • No late assignments will be accepted.


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Required Text

CCNA Routing and Switching Complete Study Guide: Exam 100-105, Exam 200-105, Exam 200-125, 2nd EditionExternal Link

Author(s): Todd Lammle (
ISBN: 978-1-119-28828-2 (2nd Edition)
Published date: September 2016
Publisher: Sybex
Also on


Use the LammleSim IOS "IOS CCNA R/S SIM" to practice the hands-on labs.


Reference Texts

Connecting to the Internet: A Practical Guide About LAN-Internet ConnectivityExternal Link

Author(s): Andrew F. Ward
Publisher: Addison-Wesley, 1999. ISBN: 0-201-37956-2
Used copies are available through Amazon.comExternal Link


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Class Notes & Assignments

Tues. Jan 30, 2018

Top / Home

News & Tools


Principle of Least Privilege

Malware (short for malicious software. e.g. Virus, Trojan Horse, Worm, Adware, etc.)



PortaPow Fast Charge + Data Block USB Adaptor


Stay Informed! News Sources

Studying & Learning Tips


Memorize these Bit Patterns of Often Used Subnet Mask Values (pdf)






































Password Managers


Backing Up: 3-2-1 Rule

Optical Media for Long Term Archives

Live AntiVirus and Recovery Discs

Troubleshooting Client Network Connectivity


Read / Watch



Thurs. Feb 1, 2018
Top / Home


More than 150,000 Internet-facing printers were scanned, located, and used


Tools and News


Identity Theft is a big problem.


Protocol Review:


Cisco IOS and Router Command Reference


Unicast, Broadcast, Multicast


Collision and Broadcast Domains



Telemetry is an automated communications process by which measurements and other data are collected at remote or inaccessible points and transmitted to receiving equipment for monitoring.


How would you know that a network has been compromised?


Network Analyzer/Packet Sniffer


Segment Your Network / Isolate Guests & IoT devices from your main segment


Ubiquiti Networks EdgeRouter X:


Universal Plug-and-Play (UPnP)

Microsoft OneNote





Tues. Feb 6, 2018
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New & Tools

Attackers Exploiting Unpatched Flaw in (Flash 02 Feb 18)

Enable Microsoft Office Protected View


QuickTime should be uninstalled from all Microsoft Windows systems


2 Factor Authentication



The Electronic Frontier Foundation (EFF) has online tracker-testing in its Panopticlick, helping you analyze the privacy protections in your Web browser.

Web Browser Plugins

Wireless Network Security




Virtual Private Network (VPN)

A virtual private network (VPN) enables users to send and receive data while remaining anonymous and secure online.

In the simplest terms, a VPN is used to create a secure, encrypted connection between your computer and a server operated by the VPN service.


Types of Ethernet cabling

Autonomous System (AS)

RFC (Request for Comments)

IEEE (Institute of Electrical and Electronics Engineers)

Deprecated / Deprecation


Cisco's Three-Layer Hierarchical Model







Thurs. Feb 8, 2018
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Rufus: Create a bootable USB from an ISO

XBoot: Create a bootable USB flash drive with multple Live OS's


Dynamic Host Configuration Protocol (DHCP)


Transmission Method


Discover broadcast --> Client requests an IP address.
The client broadcasts a DHCPDISCOVER message on the physical subnet to find available servers. The client creates a UDP packet with the broadcast destination of or the subnet broadcast address.
Offer <-- unicast DHCP server offers an IP address from its pool.
When a DHCP server receives an IP lease request from a client, it extends an IP lease offer. This is done by reserving an IP address for the client and sending a DHCPOFFER message across the network to the client. This message contains the client's MAC address, followed by the IP address that the server is offering, the subnet mask, the lease duration, and the IP address of the DHCP server making the offer.
Request broadcast --> When the client PC receives an IP lease offer, it must tell all the other DHCP servers that it has accepted an offer. To do this, the client broadcasts a DHCPREQUEST message containing the IP address of the server that made the offer. When the other DHCP servers receive this message, they withdraw any offers that they might have made to the client. They then return the address that they had reserved for the client back to the pool of valid addresses that they can offer to another computer. Any number of DHCP servers can respond to an IP lease request, but the client can only accept one offer per network interface card.
Acknowledge <-- unicast When the DHCP server receives the DHCPREQUEST message from the client, the final phase of the configuration process is initiated. The acknowledgement phase involves sending a DHCPACK packet to the client. This packet includes the lease duration and any other configuration information that the client might have requested. At this point, the IP configuration process is complete.



ARP (Address Resolution Protocol)


Neighbor Discovery Protocol (NDP)


Connection-oriented service vs Connectionless service



Subnet zero and the all-ones subnet

ICMP (Internet Control Message Protocol)

The Internet Control Message Protocol (ICMP) is one of the core protocols of the Internet Protocol Suite.

ICMP messages are divided into two broad categories: error-reporting messages and query messages.


When a packet is received by a router, what does the router have to do?

  1. Decrement TTL by 1, then evaluate TTL
  2. What is the network that the packet is destined for?
  3. Do I have that network in my routing table?
  4. If no, then drop the packet and send an ICMP destination unreachable to the sender
  5. If yes, then…



Traceroute TTL diagram


Read / Watch





Tues. Feb 13, 2018
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News & Tools




Anti-Virus, or Not?

Better Focus and Efficient Studying When Not Multitasking / Multi-Focusing


Subnet and Bits Cross-reference img


Using the AND function to determine the network address


Broadcast Address, Wildcard Mask, Block Size practice:


Default Mask vs Mask


Using the Wildcard mask to determine the last address (a.k.a. broadcast address) within a subnet.

MicroNugget: Wildcard Masks by Keith Barker


Read / Do

Practice, practice, practice:


Practice makes improvement!






Thurs. Feb 15, 2018
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Google: My Activity





Answer these questions when subnetting:


Using the AND function to determine the network address


Subneting into a Large Number of Subnets

Determine the network address of a high subnet number.

  1. Multiply the target subnet number by the number of addresses per subnet, to get the number of addresses to add to the network address (subnet zero) to jump to the target subnet.
  2. Convert the resulting number of addresses to its Base-256 (dotted-decimal) equivalent.
  3. Add the Base-256 (dotted-decimal) equivalent to the network address/subnet zero, to determine the target subnet address.

Note about the "target subnet"


Converting a Decimal Number to Base 256  (Dotted-decimal)

Example Decimal to Base-256/Dotted-Decimal Conversion (Subnetting Problem 2)



Subnetting Tips/Notes





Example Decimal to Base-256/Dotted-Decimal Conversion (Subnetting Problem 2)





Tues. Feb 20, 2018 No Class (Classes follow a Monday Schedule)
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Thurs. Feb 22, 2018
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News and Tools

Anki is a program which makes remembering things easy. Because it's a lot more efficient than traditional study methods, you can either greatly decrease your time spent studying, or greatly increase the amount you learn.

NYU Tandon School of Engineering’s NY Cyber Fellows program is an elite, affordable part-time online MS in Cybersecurity in partnership with New York City Cyber Command, with a curriculum designed in cooperation with elite corporate partners.



Assignment #1 Debriefing


Subnetting practice








Tues. Feb 27, 2018
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Assignment #2 Debriefing


Subnetting Practice






Thurs. March 1, 2018
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Classful vs. Classless Subnetting

When you’re subnetting an IP address for a network you have two options: classful and classless.

Classful subnetting is the simplest method.

Classless addressing allows you to use different subnet masks and create subnets tailored to the number of users/addresses in each group.


VLSM (Variable Length Subnet Mask)

VLSM: Configuring Subnets Using the Numeric Method (PDF)


VLSM Numeric Method Outline




Quiz #1: Subnetting




Tues. March 6, 2018
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News & Tools

LTE security flaws could be used for spying, spreading chaos

A flight of new research papers show 4G LTE networks can be exploited for all sorts of badness.


This is how little Signal knows about its privacy-loving users

Privacy win for encrypted messaging app.

World’s largest DDoS attack thwarted in minutes

Microsoft fights massive cryptocoin miner malware outbreak



Assignment #3 debriefing


Quiz #1 Debriefing



Route Summarization / Route Aggregation / Network Address Aggregation

Step 1 Convert the addresses to binary format and align them in a list.
Step 2

Locate the bit where the common pattern of digits ends.

(It might be helpful to draw a vertical line marking the last matching bit in the common pattern.)

Step 3

Count the number of common bits.

The summary route number is represented by the first IP address in the block, followed by a slash, followed by the number of common bits.





Thurs. March 8, 2018
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Exam #1

The exam includes, but is not limited, to the following:


Chapters 1 - 5 from the CCNA Routing and Switching Study Guide 2nd Edition

OSI Reference Model:

Classfull vs Classless (CIDR) IP addressing


Converting a decimal number to its Base-256 dotted-decimal form.



Troubleshooting Commands






Tues. March 13, 2018
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News and Tools

@Citizenlab catches ISPs invisibly redirecting download requests for popular programs, injecting them with government spyware. Unencrypted web traffic is now provably a critical, in-the-wild vulnerability. 20-30% of top internet sites affected.

The Hapless User: Secure from the inside out


Cisco CSS/CSM Day 828 problem


Exam 1 Debriefing


IP Subnet Practice Page (Todd Lammle)


Cisco IOS


What Is Administrative Distance?


Read / Do

Note: Until further notice, bring your text book to every class, so that you'll have access to the instructions for the Hands-on Labs.


Thurs. March 15, 2018
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Better Focus and Efficient Studying When Not Multitasking



Assignment #4 Debriefing


Telnet, Console and AUX Port Passwords on Cisco Routers Configuration Example


Set password for console access:

(config)# line console 0
(config-line)# password <password_here>
(config-line)# login





You must be in this class to get credit for this labs.


Read / Do

Note: Until further notice, bring your text book to every class, so that you'll have access to the instructions for the Hands-on Labs.



Tues. March 20, 2018
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Office Lens

Office Lens trims, enhances, and makes pictures of whiteboards and docs readable. You can use Office Lens to convert images to PDF, Word and PowerPoint files, and you can even save images to OneNote or OneDrive.



Cisco Discovery Protocol (CDP)


How Routers Talk to Each Other

Forwarding Techniques

Techniques to make the size of the routing table manageable.

Delivery of a Packet

Routing protocols:


An interior gateway protocol (IGP) is a routing protocol that is used within an autonomous system (AS).

An Exterior Gateway Protocol (EGP) is used between autonomous systems.


Prevent "Translating. domain server (" Messages after an Invalid Command is Entered on a Router




Read / Do


Read / Do

Note: Until further notice, bring your text book to every class, so that you'll have access to the instructions for the Hands-on Labs.





Thurs. March 22, 2018
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News and Tools


Routing Protocols


Category / Vector


RIP (Routing Information Protocol)

distance-vector routing

IGRP (Interior Gateway Routing Protocol)

distance-vector routing

  • considered a classful routing protocol
  • IGRP supports multiple metrics for each route, including bandwidth, delay, load, MTU, and reliability
  • maximum hop count of IGRP-routed packets is 255 (default is 100)

EIGRP (Enhanced Interior Gateway Routing Protocol)

distance-vector routing

  • Adds support for VLSM (variable length subnet mask)
  • Adds the Diffusing Update Algorithm (DUAL) in order to improve routing and provide a loopless environment.
  • EIGRP has completely replaced IGRP

OSPF (Open Shortest Path First)

link-state routing protocol

  • Routes packets based solely on the destination IP address found in IP packets.
  • Designed to support variable-length subnet masking (VLSM, CIDR).
  • OSPF detects changes in the topology, such as link failures, very quickly and converges on a new loop-free routing structure within seconds.
  • falls into the group of interior gateway protocols, operating within an autonomous system (AS)
  • the most widely-used interior gateway protocol (IGP) in large enterprise networks
  • OSPF does not use TCP or UDP but uses IP directly, via IP protocol 89. OSPF handles its own error detection and correction, therefore negating the need for TCP or UDP functions.

BGP (Border Gateway Protocol)

path vector protocol

  • makes routing decisions based on path, network policies and/or rulesets
  • v4 supports Classless Inter-Domain Routing and the use of route aggregation to decrease the size of routing tables.
  • RFC 4271
  • The most widely-used exterior gateway protocol (EGP) is BGP.



Router Configuration Checklist


Loop Prevention (Routers)

Forwarding Techniques

Techniques to make the size of the routing table manageable.



Routing Tables



Mask The network prefix (in CIDR notation) of the destination network

Network address

The network address of the destination network

Next Hop IP address

The IP address of the next neighbor router to the destination network.
Think... From the router I am on, what is the IP address of the closest router I can forward the packet to, to get that packet to the destination network?


The network interface used to get to the next hop router.
a.k.a. "Exit Interface"
Think... From the router you're on, which interface do I have to send the packet out of, to get it to the Next Hop router?




Lab-03: Building Routing Tables


Read / Do






Tues. March 27, 2018
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News and Tools


Google: My Activity


Lab-03 Debriefing


Loop Prevention (Routers)


Decoding the output from "show ip route"

This is one entry from: show ip route

O [110/74] via, 05:29:08, Serial0/0

O Routing protocol "OSPF" Remote network
[110 OSPF Administrative Distance (AD)
/74] OSPF cost
via Next hop for the /8 network
05:29:08 Aging time. How long the protocol has been running?
Serial0/0 Exit interface



Router Configuration Checklist

Cisco IOS


Router Simulator (RouterSim)


Lab-04: (Configuring Router interfaces, and the RIP Routing Protocol)


Troubleshooting: Having a problem with your lab?





Thurs. March 29, 2018
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Read / Do


Exam 2

You must be able to correctly answer all of the Review Questions from each chapter.

The exam includes, but is not limited, to the following:


Chapter 5 (VLSM)

Chapter 6: Cisco's Internetworking Operating System (IOS)

Chapter 7: Components of a Cisco Router and Switch, CDP (Cisco Discover Protocol)

Chapter 8: Managing Cisco Devices


Chapter 9: IP Routing


Chapter 18: OSPF


Describe How A Network Works


Diagnostics & Troubleshooting Commands

Forwarding Techniques

Delivery of a Packet

Logical and Physical addressing during the forwarding process:






Tues. April 3, 2018 (Spring Recess - No Class)
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Read / Do


Thurs. April 5, 2018 (Spring Recess - No Class)
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Read / Do


Tues. April 10, 2018
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Exam 2 Debriefing


Lab-04 Debriefing



Document the configuration of each router in your lab



Chapter 10: Layer 2 Switching

The three functions of a switch.

Configuring an IP address on a switch

Port Security on a Switch

(Chapter 10, pgs. 417, 428)

Restrict and shutdown violation modes alert you via SNMP that a violation has occurred on a port. (pg. 443, 3rd sentence in the 5th paragraph)


Spanning Tree Protocol (STP)

Bridge Protocol Data Unit (BPDU)


Spanning Tree Protocol (STP): Port States

The ports on a switch with enabled Spanning Tree Protocol (STP) are in one of the following four port states.





Note: "Disabled" is not one of the four STP states. Disabled (technically, is not a transition state). A port in the administratively disabled state doesn’t participate in frame forwarding or STP. A port in the disabled state is virtually nonoperational.



Read / Do / Watch




Thurs. April 12, 2018
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Exam #3 will be on Thursday: April 26, 2018


News & Tools




Cisco IOS


OSPF Router ID

The OSPF Router-ID is used to identify a specific device within an OSPF database. Router ID’s must be unique to prevent unintended OSPF database problems.


OSPF Loopback Interface

Configuring a Gateway of Last Resort Using IP Commands


Lab-05: (Serial, OSPF, DHCP)



Read / Do




Tues. April 17, 2018
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News & Tools



Chapter 11: VLANs and InterVLAN Routing


Lab-06: VLANs


Read / Do






Thurs. April 19, 2018
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News and Tools


Access Control List (ACL)

Standard ACL (1-99)

Extended ACL (100-199)

applied closest to the destination

applied closest to the source

Denies or Permits:

  • source IP address

Denies or Permits:

  • source IP address
  • destination IP address
  • port or service



Lab-07: Chapter 12: Cisco IOS: Security: Access Control Lists (ACLs)



IP Address

Network Address

Wildcard Mask



Serial 0/0 /30


Connection to SF


Serial 0/1 /30


Connection to LA


Fa0/0 /24









Fa0/0 /24




S0/0/0 /30


Connection to Corp







Fa0/0 /24




S0/0/0 /30


Connection to Corp


Read / Do



Tues. April 24, 2018
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Lab-08: Chapter 10 Hands-on Lab

Chapter 11 Hands-on Lab: VLANs


Read / Do



Thurs. April 26, 2018
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Read / Do


Exam #3: In Class, via Blackboard

To be prepared for this, and any of the exams, you must be able to answer all of the Review Questions at the end of each chapter.

This exam includes, but is not limited, to the following:


Chapter 10: Layer 2 Switching

Chapter 11: VLANs and InterVLAN Routing

Chapter 12: Security: Access Control Lists (ACL)

OSI Reference Model

Troubleshooting Commands and syntax



Read / Do




Tues. May 1, 2018
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Guest speaker presentation on IT Project Management w/Q&A


News & Tools

Windows Subsystem for Linux (WSL)


NAT Router Security Solutions: Tips & Tricks You Haven't Seen Before

GRC’s Link Farm


Trello’s boards, lists, and cards enable you to organize and prioritize your projects in a fun, flexible and rewarding way.



Exam 3 Debriefing



Network Address Translation (NAT)

What does a NAT router do? A NAT router creates a local area network (LAN) of private IP addresses and interconnects that LAN to the wide area network (WAN) known as the Internet. The "Network Address Translation" (NAT) performed by the router allows multiple computers (machines) connected to the LAN behind the router to communicate with the external Internet.1


Lab-09: Chapter 13: Network Address Translation (NAT)


Read / Do


Thurs. May 3, 2018
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News & Tools

Lucidchart provides an intuitive and collaborative diagramming solution for your entire organization.



Three strategies for the transition from IPv4 to IPv6:


Advantages that IPv6 has over IPv4.

IPv6 Addressing


Global Unicast IPv6 Address

Subnet ID -

Interface ID -

IPv6 Address Format

IPv6 Address Format: x:x:x:x:x:x:x:x ? where x is a 16 bit hexadecimal field, and x represents four hexadecimal digits.

An example IPv6 Address: 2001:0000:5723:0000:0000:D14E:DBCA:0764

There are:

IPv6 (128-bit) address contains two parts:

Note: Addresses are assigned to interfaces (network connections), not to the host. Each interface can have more than one IPv6 address.


IPv6: Zero Omission Rules



What is the command to configure OSPFv3 on a router?


Stateless Autoconfiguration (EUI-64)

[Reference: Ch. 14 Pg. 556]

SLAAC (State Less Automatic Address Configuration):

Stateless Autoconfiguration is a useful solution because it allows devices on a network to address themselves with a link-local unicast address as well as with a global unicast address. This process happens through first learning the prefix information from the router and then appending the device’s own interface address as the interface ID.

To perform autoconfiguration, a host goes through a basic two-step process:

  1. First, the host needs the prefix information, similar to the network portion of an IPv4 address, to configure its interface, so it sends a router solicitation (RS) request for it. This RS is then sent out as a multicast to all routers (FF02::2). The RS message is ICMP type 133.
  2. The router answers back with the required prefix information via a router advertisement (RA). An RA message also happens to be a multicast packet that’s sent to the all-nodes multicast address (FF02::1) and is ICMP type 134. RA messages are sent on a periodic basis, but the host sends the RS for an immediate response so it doesn’t have to wait until the next scheduled RA to get what it needs.

What is the problem with StateLess Automatic Address Configuration (SLAAC)?

Mastering IPv6 SLAAC Concepts and Configuration


DHCPv6 (Stateful) (IP and Options)

[Reference: Ch. 14 Pg. 559]

- Static
- Stateful DHCP (IP and Options)
- Stateless DHCP (no IP, just Options) [DNS, Domain you belong to.] (Used with SLAAC)



Lab-10: Chapter 14: IPv6


Read / Do

Assignment #5: IPv6 Zero Omission Rules


Read / Do




Tues. May 8, 2018
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A EUI (Extended Unique Identifier)-64-bit interface identifier is most commonly derived from its 48-bit MAC address.

Example 1:

We usually see the MAC in the following format: 00:90:27:16:fd:0f

Step 1: Transform the MAC Address

Step 2: Flip the 7th bit:

Take the first two hex digits (from the left) and write them in binary.

  2nd Hex digit



















Original value










Resulting value












Read / Do


Thurs. May 10, 2018
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Quiz 5 - Fix Me Challenge!





Read / Do

Tues. May 15, 2018
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News and Tools


Quiz 5 Troubleshooting Challenge Hands-on Lab Debriefing


Hands-On Lab


Read / Do

Thurs. May 17, 2018: No Class (Classes Follow Wednesday Schedule)
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Read / Do


Tues. May 22, 2018

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Mark Russinovich (

Final Exam


(Note: This outline of the final exam may change, so check often for updates.)


The final exam includes, but is not limited, to the following:


Chapter 13: Network Address Translation (NAT)

Network Address Translation (NAT) allows many inside IP addresses to be represented by some smaller number of outside/public IP addresses.


Types of NAT, and how they work:

NAT terms

CCNA CCNP Training - No confusion with IP NAT Inside Outside Local Global


Chapter 14: Internet Protocol Version 6 (IPv6)

Chapter 15: Enhanced Switched Technologies

Cisco IOS Diagnostic Commands



Recommended Web Sites and Books


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