Wireless: Starting Chapter 5

short notes today, we took a test in the beginning of class and the review went quite long.

Low Rate Wireless Personal Area Networks

What is WPAN?

• Wireless personal area network
• Group of technologies that are designed for short-range comminications
• Eliminates the need for wires or cables to interconnect multiple devices
• Applications for WPAN technology include:
• Synchronizing PDA's, cellular, and Smartphones
• Home control systems (smart home)
• Cordless telephones
• Portable device data exchange
• Industrial control systems
• Location- smart tags used to locate people at home or the office
• security systems
• interactive toys
• inventory tracking
• Advantages
• WPAN devices use very little power
• short range helps maintain security and privacy

OSI vs IEEE 

• Data Link layer
• Logical link control (LLC)
• Media access control (MAC)
• PHY layer
• physical layer
• j;

Infrared WPANs (IrDA)

• most common infrared connection today
• based on the irDA specifications
• IrDA specifications
• define both physical devices and network protocols
• IrDA devices characteristics
• provide walk-up connectivity
• provide point to point method of data transfer
• between only two points at a time

IrDA considerations

• Factors to consider:
• half duplex transmission
• deflection angle
• ambient light
• ease of use
• security
• distance limitations

Uhoh!  Digressions!

ZigBee Homepage

IEEE and Bluetooth

• Bluetooth RF layer
• defines how the basic hardware that controls the radio transmissions functions
• data bits are converted into radio signals and transmitted
• Modulation technique
• Bluetooth uses a variation of FSK
• two-level gaussian frequency shift keying (2-GFSK)
• uses two different frequencies 
• to indicate whether a 1 or 0 is being transmitted
• modulation index
• amount that the frequency varies
• between 280 KHz and 350 KHz
• Baseband layer
• lies on top of the RF layer
• manages physical channels and links
• handles packets, and does paging and inquiry
• to locate other bluetooth devices in the area
• Radio frequency
• 2.4GHz ISM band (industrial, scientific, medical)
• devides frequency into 79 different channels
• spaced 1 MHz apart
• bluetooth uses FHSS
• uses the same frequency as IEEE 802.11b WLANs
• they can interfear with each other
• Bluetooth V 1.2 added a feature called adaptive FH
• which further improves compatibility with 802.11b
• Network topologies
• piconet and scatternet
• bluetooth devices
• master controls all of the wireless traffic (phone)
• slave takes commands from the master (earpeice)
• piconet 
• bluetooth network that contains one master and at least one slave and that uses the same channel
• Each bluetooth device is preconfigured with an address 
• needed when participating or not participating in the piconet
• 
  

Wireless: Chapter 4 review

ORAU/ORNL Internships - HERE and SULI are the ones that are being recruited right now.

Field trip Oct 26 to Cumulus Broadcasting

Went over the Review Questions.  I'll upload it later and add a link.

True North vs Magnetic North.  Pretty sure that True North is only found by survey  Magnetic North is found with a compass.

And now we get to take a "field trip" to the radio tower across the street.

Wireless: More Chapter 4

Nov 4th-9th IETF is hosting a meeting in Atlanta GA.  He's pushing for people to go at least for one day and trying to see if the student group will be able to help pay for it.

Not too much digression at the beginning of class today, so notes after the jump.

**Please note, for some reason I cannot add pictures to these anymore.  If you need to see the pictures, please see the slideshows until I can get this fixed.**

Log Periodic Antenna

R/S Chapter 5 Start

Chapter 5 will be covering the following:

The Cisco IOS boot process in detail. 

Will also be going over backing up which includes the IOS and the config files. 

And last, CDP- Cisco Discovery Protocol. 





Notes after the break.

Wireless: More Ch 4

Jerry's been yakkin quite a bit.  Showed us some different types of antennas in class.

Reviewed pictures/graphs showing filters and what is blocked. 

Wavelength (meters)( λ) = 300/F MHz - remember this, it'll be on the test and used.  

Extra Credit ops-              Ham Fest in Severville 9/29 50points

                                        LOPSA meeting 10/2 30points

Digressions links, unsure where they fit in, but looks important.
Dipole Antennas

Cell Phone Booster

Notes from class (such as it is) after the break.

Wireless: Ch 4 cont.

Short one today, as we had a test and Jerry talked quite a bit on unrelated stuff.  Also, sorry about the format, the keyboard I had was sticky and I could not type well, I had to copy/paste from the powerpoint slides. 

Antenna Characteristics

Types, sizes and shapes

Passive antennas

–The most common type

–Constructed of a piece of metal, wire, or similar conductive material

–Does not amplify the signal in any way

–Directional gain

•Passive antennas radiate the RF energy supplied by the transmitter in one direction

•Exhibits an effective gain that is similar to amplification of the signal

Wireless: Start of Ch 4

Supplemental notes for the review of Ch 3. 

High pass aka low cut

Low pass aka high cut

The spike or raised area on any graph shows the BLOCKED frequencies.

Chapter 4 start

Gain and Loss

Understanding RF signal transmission involves the strength or power with which the transmitter is sending out the signal, the amount of reduction in signal strength caused by cables, connectors, and other components, the transmission medium and the minimum strength of the signal required by the receiver to be able to properl recover the data sent by the transmitter. 

An amplifier boosts the power of a signal, called a gain.  Cables and connectors offer a resistance to the flow of electricity and tend to decrease the power of a signal (loss).  Signal power changes logarithmically and gains and loss are relative concepts.  You need to know the power level of the signal at two different points. 

Wireless Ch 3 cont

Signal Strength cont.

 

Directional Antenna is used to minimize multipath distortion and radiates electromagnetic waves in one direction only.

There are other methods to reduce multipath distortion; using an amplifier in front of receiver to increase SNR and transmitting the same signal on separate frequencies.

Wireless: Chapter 3, Radio Communications

Filters removes unwanted F signals.  RF filter either passes or rejects a signal based on frequency.  There are three basic types of filters; low-pass, high-pass and bandpass filters.  Low pass blocks the high, lets the low through, high blocks low and keeps high.  The bandpass sets a range called a passband, which has a min and max threshold.  

R/S: Cisco Router IOS Start

9/17 notes- Cisco Routing

Cisco Router IOS

How do I access my router?

Physical – hooking up a wire and logging into the device

Remote- using SSH or TelNet to log in remotely

How do I configure my router?

Console Port

            Designated by a light blue color and label

            Console cable has one RJ45 port and one Serial port.  The RJ45 goes into the router, serial into the computer. 

Via modem using an aux port – only found on older routers

Virtual terminal

Tftp server

Playing Catchup

I'll get everything that I have missed posted in the next few days.  Life kinda crashed into me all at once, so little time has been had to sit and organize notes to make them play well with the blog.

R/S: Troubleshooting

Don’t do things in random order, but a set of steps.

First step is to define the problem.  Try to isolate the problem. 

Four step troubleshooting:

1 Ping loopback address- trying to isolate the problem Ping 127.0.0.1 When you ping the loopback, you are checking if the TCP/IP software is on the computer, available and working correctly.  There is always a file on the computer that has the loopback address, and if that folder is deleted, the network connections will not work correctly.

2 ping ip address of the local system (192.168.40.10)  When pinging the local system, you are checking if the NIC is working or not.  If these two steps are successful, you know that the user’s machine is ok. 

3 Ping the default gateway ex: ping 192.168.40.1.  A default gateway is the router, which is your translator between the inside network and your outside network. 

4 ping a system outside your local network- google, yahoo, ect.  At this point, we know that the local system is ok, now we are looking to the outside network for the issue.

***These are the specific order that has to be done on the tests and the CCENT test***

More After the Break

Wireless: End of Chapter 2

Went over audio stuff, sample size and rate.  Not sure what this has to do with chapter 2….

Digital Modulation Cont.

-Binary signals are digital data transmissions are typically sent in bursts of bits.  There are three types of binary signaling techniques that can be used:

Return-to-zero (RZ) calls for the signal to rise to represent 1 bit.  It must return to zero in its allotted time.

Non-return-to-zero (NRZ) the voltage signal remains positive, or high, for the entire length of the bit period.

Polar non-return-to-zero (polar NRZ) raises the signal to represent a 1 bit, but drops to a negative amount to represent a 0 bit.  Works well with light by using different colors.

A variation on a non-return-to-zero-level is a non-return-to-zero, invert-on-ones (NRZ-I).  A change in voltage level represents a 1 bit, whereas no change in voltage level indicates that the next bit is a 0. 

 The rising edge is on the left of the pulse, the falling edge is on the right.  The top is the level edge of the pulse.  

More After the Break

Wireless: More Chapter 2

Analog and Digital 

-Analog signal intensity (voltage or amplitude) varies and is broadcast (occurs) continuously.  Examples are audio, video, voice and light.
-You turn it on, ramps up like a lightbulb, when the power is cut, it powers down and the signal ramps down.

-How do you get a negative voltage with a battery?  Turn it around ;)

-LED cannot use a backward battery.  The way they are built, it only conducts in one direction, so if the flow is reversed, it is blocked, sometimes catastrophically.

-The flow of energy in a battery is out the negative side (gtfo!) and in the positive.

-DC (direct current) Resistance causes electrons to lose their energy over time. 

-AC The highest points are called peaks, the lowest is also called a peak.  P-P (peak to peak) voltage is calculated by the distance between the two.   

-Digital signal consists of discrete or separate pulses.  It has numerous starts and stops throughout the signal stream, for example; Morse code.  Computers operate using digital signals.  The analog signal must be converted into a digital format before it can be stored and processed or interpreted by a computer. 

-A Modem (modulator/DEModulator) is a piece of equipment that converts the distinct digital signals from a computer and encodes them into a continuous analog signal for transmission over analog phone lines.  Modulation is the process of encoding the digital signals (bits) onto an analog wave.

More After the Break

R/S Subnetting Videos

Subnetting Made Easy pt 1

Subnetting Made Easy pt 2

Wireless: Data Transmission

We are using Wireless# Guide to Wireless Communications by Jorge Olenwa and Mark Ciampa.  The pictures on here are screen clippings from either the book or the power points that my instructor is using. 

This first post is two classes combined. 

Chapter 2- Wireless Data Transmission

Notes and stuff after the break

Routing/Switching: Review Notes

**All notes with the CSIT 2750 Routing/Switching tag and labeled R/S are derived from Nathawat Laxman's classes.  If you wish to use any of these notes, you must give credit to him, as this is his work, not mine, not something out of a textbook** 

Most of this is going to be a review of my notes from the Network Fundamentals class.  Over time, I may add links to videos on subnetting as well.

Segments of Original Notes

More after the break

I'm Baaaack!

So after some thinking (scary, I know) I think I am going to expand on this blog a little.  I think what I am going to do is share my class stuff from at least Routing and Switching and the Wireless classes I am taking this semester.  I am also taking Java, but am probably not going to be doing much on that here, as its mostly stuff I don't really understand.  So, look for some changes, don't be alarmed when things are being shuffled around. 

LAST NEWS OF THE SEMESTER!!!!

YES!  It's TRUE!  Last class meeting of the semester, and this news is it!

VMware Source Code Stolen and Posted Online

Right now the company says that the impact should be minimal, since what was stolen is one file from....

..... 2003 or 2004.

The code was stolen from a Chinese company in March.

So, if you use VMware, review your security for your virtual environments.  That's all you can do for now since very little is known about what the real impact will be.

Security News 4/19

CISPA, if you have not heard, is the new PIPA and SOPA.  But you know its bad when the White House says something along the lines of "uh, this isn't the greatest idea".

White House raises concerns over CISPA bill

In a nutshell, this bill would allow ISPs to monitor you- and gather any information that they want to on you if they feel you are a threat. Not too outside the realm of how it works now, but there is NOTHING written in the bill that would keep them from accessing your private emails, chats and Facebook posts.  All they would have to say is "cybersecurity threat!!!!" and off they would go.

The idea behind the bill is sound, but I want my freaking private stuff kept private.  It's none of anyone's business if I want to send my husband a dirty email. >.<

Security News for 4/12

Yes, I know that I have not been keeping up with this very well.  As soon as I get all my papers written for other classes, I plan on going back and filling in the gaps.

Today's post, however, is for Thursday's class.  While searching for our weekly news article, I stumbled across this little gem:

Hotel's Free Wi-Fi Comes With Hidden Extras

Basically, this hotels' ISP is injecting code into every website you visit that is supposed to show whatever ad they want you to see- regardless of what's supposed to be there, and without the knowledge of both the user and the page creator.

Now, imagine if that particular coding got hacked.  Yeah.  That's some scary shit right there.

Chapter 7 Notes

Administering a Secure Network

Objectives

¨  List and describe the functions of common network protocols

¨  Explain how network administration principles can be applied

¨  Define the new types of network applications and how they can be secured

Common Network Protocols

¨  Protocols

¡  Rules of conduct and communication

¡  Essential for proper communication between network devices

¨  Transmission Control Protocol/Internet Protocol (TCP/IP)

¡  Most common protocol suite used for local area networks and the Internet

¨  IP

¡  Protocol that functions primarily at Open Systems Interconnection (OSI) Network Layer (Layer 3)

¨  TCP

¡  Transport Layer (Layer 4) protocol

¡  Establishes connections and reliable data transport between devices

¨  TCP/IP uses a four layer architecture

¡  Network Interface, Internet, Transport, Application

More after the Break

Chapter 6

Network Security

Objectives

¨  List the different types of network security devices and explain how they can be used

¨  Define network address translation and network access control

¨  Explain how to enhance security through network design

Security Through Network Devices

¨  Not all applications designed, written with security in mind

¡  Network must provide protection

¨  Networks with weak security invite attackers

¨  Aspects of building a secure network

¡  Network devices

¡  Network technologies

¡  Design of the network itself

More after the break

Chapter 5 Notes

From here on out I am transcribing the power points that Jerry provides.  He's teaching directly off of them.

Host, Application, and Data Security

Objectives

¨  List the steps for securing a host computer

¨  Define application security

¨  Explain how to secure data using loss prevention

Securing the Host

¨  Three important elements to secure

¡  Host (network server or client)

¡  Applications

¡  Data

¨  Securing the host involves:

¡  Protecting the physical device

¡  Securing the operating system software

¡  Using security-based software applications

¡  Monitoring logs

More after the break

Chapter 4 review

It's up.  Next week is Spring Break and I'll try to get caught back up on publishing notes.

Chapter 4 Review

Even more Chapter 4 notes

Vulnerability Assessment cont.

• Vulnerability appraisal
• Determine current weakness
• Snapshot of current organization security
• Every asset should be viewed in light of each threat
• Catalog each vulnerability

• Risk assessment
• Determine damage resulting from attack
• Assess likelihood that vulnerability is a risk to organization

More after the Jump

Chapter 4

Chapter 3 review

Vulnerability Assessment

• Systematic evaluation of asset exposure
• Attackers
• Forces of nature
• Any potentially harmful entity

• Aspects of vulnerability assessment
• Asset identification
• Threat evaluation
• Vulnerability appraisal
• Risk assessment
• Risk mitigation

More after the break!

Security News!

CompTIA pushing Certification to Manage Security Risks

41% of US organizations are reporting deficiencies in security levels due to lack of training in their techs.

More and more companies are turning to certifications to validate expertise in their candidates.  Make sure that you review your options between formal training, OJT and certs- or a combination of the three.  

More Chapter 3

Sorry about the order!  I had an appt in Johnson City on the second and had to get the notes.  Here they are, in all the out-of-order glory!

Test Today on Chapter 2

Client-Side Attacks cont'd

• Session hijacking
• Attacker attempts to impersonate user by stealing or guessing session token

• Malicious addons
• Browser extensions provide multimedia or interactive Web content
• Active X addons have several security concerns

More after the Break!

News for Feb 9

Small DDoS attacks can (and will) do just as much damage as a large scale attack will.

DDoS Attacks: Size doesn't matter

According to Radware, size doesn't matter when it comes to DDoS attacks.

Radware's ERT found that the majority of successful attacks were made with less that 1 Gigabit per second.  Others work by devouring server resources.  They also found that firewalls and IPS alone cannot stop DDoS attacks, and in some cases, the firewall is the weakest link.

What can you do?  Collect information about all attacks, not just the big ones.  Do your risk analysis.  Be ready and willing to work with your ISP.

Don't assume that you are not at risk for a DDoS attack just because you are small.  Plan for the worst.

Chapter 3 Cont

Money potential:  Setting up own questions to learn and pass the Security + exam.

Network Attacks

• Denial of service (DoS)
• Attempts to prevent system from performing normal functions
• Ping flood attack
• Ping utility used to send large number of echo request messages
• Overwhelms Web server
• Smurf attack
• Ping request with originating address changed
• Appears as if target computer is asking for response from all computers on the network
• SYN flood attack
• Takes advantage of procedures for establishing a connection

• Distributed denial of service (DDoS)
• Attacker uses many zombie computers in a botnet to flood a device with requests
• Virtually impossible to identify and block source of attack

More  after the break

Chapter 3 beginning

Application and Network Attacks

Application Attacks

• Attacks that target applications
• Category continues to grow
• Web applications attacks
• Client-side attacks
• Buffer overflow attacks

• Zero day attacks
• Exploit previously unknown vulnerabilities
• Victims have no time to prepare or defend

More after the break