(LAN/WAN/MAN fundamentals)

Network Classifications and topologies:

Networks are classified according to the area they are covering. For instance the smallest network consists of two nodes connected to each other. The largest networks could be hundreds or thousands of nodes connected to another.

LAN: A LAN or Local Area Network would consist of a few computers, the best way to think about what a LAN is, would be everything behind the router that gets a private IP address (10.or 192.). A segment is a portion of the LAN where nodes are connected directly. LAN's can have multiple segments tied together.

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MAN: A MAN or Metropolitan Area Network is a network that crosses cites. MAN's uses public connections to get information from one area to the next over the city like T1 or T3. They also use switched services like Integrated Service Digital Network (ISDN), frame relay, Asynchronous transfer mode (ATM), or wireless services. 


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WAN: A WAN or Wide Area Network would be across a region or the world. For instance from city to city or country to country. Information travels only on a WAN when it needs to leave the city for another.

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( NETWORK TOPOLOGY )
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- BUS TOPOLOGY -

This happens to be a single electrical circuit to which all devices in a network are connected. This may be a bunch of different little connections and wires. A bus topology is a broadcast network, meaning when a computer or node transmits data, the signal travels down the bus in both directions and every node or computer connected to the bus will receive the signal. If the signal is not meant for the node or computer it simply ignores it.

Once a signal is at the end of the bus there is a terminator at the end which prevents it from reflecting back. If the bus cable breaks, this means all nodes or computers end up with a loss of internet unless redundant network is in place.                                                                   

 

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- STAR TOPOLOGY -

Having a star topology is the most common topology. Using a central unit such as a switch or hub to communication data, this also is a broadcast network. This is a little different however, for instance if a hub is used then everyone attached to the hub hears everything transmitted.

 If this is switch then it will transfer the packet to the correct port, but is still susceptible to broadcast traffic. If the central unit is down, then again all nodes or computers is going to be down as well.

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 - Ring Topology -

A true to the heard ring technology is many point to point links arranged in a ring fashion. Each of the nodes or computers network interface cards (NIC) has one input and one output connection, so therefore is connected to two links.

When an input connection receives a signal, it re-transmits the signal without buffering to its output connection. This makes it so the flow of data is only in one direction, if the data makes it to a node that it is intended for, the node copies the data and keeps it as it travels down the line, if not, it will simply re-transmit.

The ring will be shut down if any lines are broken, this will not come back up until the wire or node is replaced. Some Fiber Distributed Data Interface (FDDI) have a back up line called duel ring structure to prevent down time and ensure redundancy. Ring topologies are often used as network backbones, this can often connect multiple business floors or even a campus network or a MAN. 

- Star Ring Topology -

As you may of guessed it, a star ring topology combines the star and the ring technology. It combines the physical star configurations with a logical of ring information flow. The star ring topology wires run from each node to a central ring wiring concentrator, this is also often called a multi-station access unit (MAU). 

This creates a physical star topology but travels in a ring logically so it has the ability to see a down node and keep the circuit up.

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- Mesh Topology -

This mesh topology, point to point links directly connect every site to every other site. Mesh networks are usually built over tome as new sites sometimes are added or subtracted from the overall network. The mesh network topology is often used for MAN or WAN networks.

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My information was backed up by the 8th edition of the introduction to Local Area Networks from WestNet Learning.

Four port Netgear router administration password reset:

I have spoke to a several people over the last week and noticed a few common issues.



There can be many reasons that you want to reset the password on your router. Change for security, not known, or even stolen and used without authorization. Physical security is always important as direct access to the router device means easy access to your network.



The first thing you want to do to reset your router to factory settings is grab yourself a paper clip or pin. On the back of the router there is a little hole with a button in it. Often this will be labeled as reset or factory reset. Pushing this sets all passwords and settings to when you first bought it.



Now that you have changed back to default, you want to add security onto your networking device. Some routers come with an instructional CD that will walk you through setting it up. I will explain the way if you do not have the luxury of that CD.

The first thing you want to make sure is that you are connected via Ethernet cable from the router to a computer.  Make sure your computer is set up for DHCP or to auto obtain IP addresses.



Open your command prompt and at the blinking cursor type in ipconfig. This will give you your default gateway and with that, your access to the routers internal pages. This number could be different things but for this blog I will choose the common 192.168.0.1.



Open your web browser (Chrome, Internet Explorer, or Firefox) and the first thing you want to do is clear all the information at the top of the address bar (Even the http ://). Enter that default gateway (192.168.0.1) and hit enter. This should bring up a username and password request.

The default user name should be Admin and the password will either be blank or the word password. If those don’t work, contact your router manufacture for details. Once inside the routers internal pages, you can then start setting up your security.



The first settings you want to change are the password for access to internal pages. This is commonly located in the maintenance area. You will most likely get kicked out after you change this password, if you do, simply follow the instructions one paragraph above to regain access using the password you just created.



The next settings you want to change will be the wireless password if you so choose to use one. This will help keep your network safe by allowing only authorized use of the network and internet. To start this, often look in the advanced settings and it may say wireless settings.

Most cases want to enable the SSID or make it visible to the public. Anyone can see this broadcast but still require a password for access.



In the wireless settings part of your router, you will have the ability to change the SSID name. This is optional but are often changed it if there are multiple routers. Next you want to pick your security options; normally I set to the highest use (WPA-PSK [TKIP] + WPA2-PSK [AES]).

Next is your security phrase, this will be the password people are to enter when asked for a wireless password when trying to connect to a router or access point.



After that the rest is not needed for an everyday user, your IT person can help with the rest.



Thanks for reading!

kb.netgear.com

Sabotage Networks

Project Management

This blog is here to help me and others if they wish to remember a small part of what I have learned in Project Management. Most of the material I will post here is cited from the book Information Technology and Project Management fifth addition by Kathy Schwalbe.

Introduction to this chapter will give you a better understanding for Project Management. Objectives include:

• Understanding the growing needs of project management
• Explain what a project is and lists attributes of projects and triple constraints
• Discuss key elements of PM framework including project stakeholders, common tools
• Relationship between project, program, and portfolio management
• Understanding the role of the Project Manager
• History of Project Management and the importance of certifications and ethics

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What is a project?

The term "project" is a temporary endeavor undertaken to create a unique product, service, or result. Often people get this confused with the operation of something, but they are different because in projects they have a ending when the objectives are reached, where a operations might be something that could go on forever.

Projects can be very large or small, they may involve one person or even as many as thousands. They can be done in one day or even take years to complete. Some examples of Information Technology Project Management includes help desk or technical worker, software developmental team, infrastructural issues, development of new systems and more.

A 2006 baseline magazine survey pf 1,440 executives list the top ten technology projects to be VoIP, outsourcing, data networking, customer relationship management, desktop upgrades, application performance management, business analytic, and compliance tracking. These are a wide variety of projects and and organizations rely on those technologies for their success.

Project Attributes

A project has a unique purpose: Every project should have a well defined objective. For example a project management office might sponsor an information technology collaboration project to devolop a list and initial analysis of potential information technology projects that might improve operations for the company. The unique purpose of this project would be to create a collaborative report with ideas from people throughout the company. Results would provide the basis for further discussions and projects.

A project is temporary and has a definite beginning and definite end. Information technology project someone might form a team of people to work immediately and get updates every so often.

A project is developed using progressive elaboration. Projects are often defined broadly when they begin, and time passes, the specific details of the project become clearer. Therefore , projects should be developed in increments. A project team should develop initial plans and then update them with more detail based on new information.

A project requires resources, often from various areas. Resources include people, hardware, software and other assets. Many projects cross departmental or other boundaries to achieve their unique purposes.
For the information technology collaboration project, people from information technology, marketing, sales, distribution, and other areas of the company would need to work together to develop ideas. A company might also hire outside consultants to provide input. Once the project team has selected key projects for implementation, they will require additional hardware, software, and network resources. People from other companies like product suppliers and consulting companies, these will become resources for meeting new project objectives. Resources are limited, they must be used effectively to meet project and other corporate goals.

A project should have a primary customer or sponsor. Most projects have many interested parties or stakeholders, but someone must take the primary role of sponsorship. The Project sponsor usually provides direction and funding for the project. The sponsors for those projects would be senior managers in charge of the main parts of the company affected by the projects. An effective project manager is crucial to a project's success. Project managers work with the sponsors, project team, and the other people involved in a project to meet the project goals.

How basic networking works

CCNA Internetwork Basics

I have got my information from my CCNA book sixth Edition by Todd Lammle.

Networks and networking has grown exponentially over the last 15 years, they have evolved to light speed to keep up with huge increases in basic mission critical user needs such as sharing data and network printing.

If you have two computers connected to hub this would be a basic LAN connection, this is one collision domain and one broadcast domain. If you don't know what these terms are so doing fret, I will be going over them at a later time.

So Bob's computer wants to talk to Sally's computer, they are on the same LAN with a multi-port repeater (HUB), so how does Bob's computer talk to Sally's computer? Does Bob say, hey Sally are you there, or hey 192.168.x.x are you there? Not since it is on the same LAN it would be using the MAC addresses that are burned into the network interface card (NIC).

So how does Bob know what Sally’s mac address is if they have never communicated before? Bob will start with name resolution (hostname to IP address resolution), this is accomplished by using the Domain Naming Service (DNS). Really since they are on the same LAN, they don't need DNS; they can broadcast asking for Sally for her information. Bob can ask everybody on the subnet who has the host name sally? Sally will respond with I am over here and here is all my information. Then Bob can store that information in what is called the prefetch file. Prefetch is like a DNS for the computer, the computer will look up his own "prefetch" file and if it cannot find what it needs there then it will ask the default gateway.

Network segmentation is how we break up bigger networks into smaller ones, you do this with devices like routers, switches, and bridges. Hubs do not break up collision or broadcast domains, switches will break up collision domains but still keep one big broadcast domain. Big broadcast domains can cause network congestion, below are some common LAN traffic congestion.

1.     To many hosts in a broadcast domain

2.     Multicast

3.     Broadcast storms

4.     Low bandwidth

5.     Adding hubs for connectivity (to many hosts)

6.     Tons of ARP or IPX traffic 

Routers are used to connect network together and route packets of data from one network to another. Routers by default break up collision and broadcast domains. Routers also provide a WAN connection as well. Breaking up broadcast domains are important because when a host or server sends a network broadcast, every device within that broadcast domain has to stop what they are doing to hear the message.

When a router's interface receives a broadcast on a port, it says thanks but no thanks and drops the packet(s). Routers also break up collision domains; there are a few advantages of using routers on a network. They do not forward broadcasts; they can filter the network based on a layer 3 information (IP address), packet switching, packet filtering, internetwork communication and path selection.

We sometimes call routers layer 3 switches, unlike layer 2 switches, which forward or filter frames, routers use logical addressing and provide what is called packet switching. Routers can also provide packet filtering by using access lists, and when routers connect two or more networks together, they use logical addressing, this is called an internetwork. Routers use routing tables (map of the internetwork) to make path selections and to forward packets to remote networks. Switches do not create internetworks; they are employed to add functionality to a network LAN. The main purpose of a switch is to make the LAN work better or to optimize its performance, providing more bandwidth to the users on that subnet. Switches do not forward packets to other networks as routers do; instead they only "switch" frames from one port to another within the switched network. 

Bridging was introduced before routers and hubs were introduced, so its pretty common to hear people referring to bridges as switches. They basically do the same thing; break up collision domains on a LAN.