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One Big Flat Network

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There is a natural movement of networks to become unnecessarily complicated.  But there is great value in keeping networks clean and simple.  Simple networks are easier to manage, more performant and more reliable while being generally less expensive.  Every network needs a different level of complexity and large networks will certainly need an extensive level of it, but small businesses can often keep networks extremely simple which is part of what makes smaller businesses more agile and less expensive, giving them an edge over their larger counterparts.  This is an edge that they must leverage because they lack the enterprise advantage of scale.

There are two ways to look at network complexity.  The first is the physical network – the actual setup of the switches and routers that make up the network.  The second is the logical network – how IP address ranges are segmented, where routing barriers exist, etc.  Both are important to consider when looking at the complexity of your network.

It should be the goal of any network to be as simple as possible while still meeting all of the goals and requirements of the network.  

The first aspect we will address is the physically flat network.   Reducing a physical network to be flat can have a truly astounding effect on the performance and reliability of  that network.  In a very small network this could mean working from a single switch for all connections.  Typically this is only available for the very smallest networks as switches rarely are available above forty-eight or possibly fifty-two ports.  But for many small businesses this is completely possible.  It may require additional cabling for a building, in order to bring all connections back to a central location, but can often be attained – at least on a site by site basis.  Many businesses today have multiple locations or staff working from home and this can make the network challenges much greater, although each location can strive for its own simplicity in those cases.

As a network grows the concept of the single switch can be grown as well using the concept of switch stacking.  Stacked switches share a single switching fabric or backplane.  When stacked they behave as a single switch but with more ports.  (Some switches do true backplane sharing and some mimic this with very high speed uplink ports with shared management via that port.)  A switch stack is managed as a single switch making network management no more difficult, complex or time consuming for a stack than for a single switch.  It is common for a switch stack to grow to at least three hundred ports if not more.  This allows for much larger physical site growth before needing to leave the single switch approach.

In some cases, some large module single switch chassis will grow even larger than this allowing for four hundred or more ports in a single switch but in a “blade like” enterprise switching chassis.

By being creative and looking at simple, elegant solutions it is entirely possible to keep even a moderately large network contained to a single switching fabric allowing all network connections to share a single backplane.

The second area that we have to investigate is the logical complexity of the network.  Even in physically simple networks it is common to find small businesses investing a significant amount of time and energy into implementing unnecessary subnets or VLANs and all of the overhead that comes with those.

Subnetting is rarely necessary in a small or even a smaller medium-sized business.  Traditionally, going back to the 1990s, it was very common to want to keep subnets to a maximum of 256 devices (or a /24 subnet) because of packet collision, broadcasts and other practical issues.  This made a lot of sense in that era when hubs were used instead of switches and broadcasts were common and network bandwidth was lucky if it was 10Mb/s on a shared bus.  Today’s broadcast light, collision free, 1Gb/s dedicated channel networks experience network load in a completely different manner.  Where 256 devices on a subnet was an extremely large network then, having more than 1,000 devices on a single subnet is a non-issue today.

These changes in how networks behave mean that small and medium businesses almost never need to subnet for reasons of scale and can comfortably use a single subnet for their entire business reducing complexity and easing network management.  More than a single subnet may be necessary to support specific network segmentation like separating production and guest networks, but scale, the reason traditionally given for subnetting networks, becomes an issue solely of larger businesses.

It is tempting to want to implement VLANs on every small business environment as well.  Subnetting and VLANs are often related and often confused, but subnets often exist without VLANs, while VLANs do not exist without subnets.

In large environments VLANs are a foregone conclusion and it is simply assumed that they will exist.  This mentality often filters down to smaller organizations who are often tempted to apply this to businesses which lack the scale that makes VLAN management make sense.  VLANs should be relatively uncommon in a small business network.

The most common place where I see VLANs used when they are not needed is in Voice over IP or VoIP networks.  It is a common assumption that VoIP has special needs that require VLAN support.  This is not true.  VoIP and the QoS that it sometimes needs are available without VLANs and often will work better without them.

VLANs really only become important when either management is needed at large scale (where scale is larger than a single subnet can provision) and cannot be physically segregated or when specific network-layer security is needed which is relatively rare in the SMB market.  VLANs are very useful and do have their place.  VLANs are often used if a dedicated guest network is needed but generally in a small business guest access is provided via a direct guest connection to the Internet rather than a quarantined network for guests.

The most common practical use of a VLAN in an SMB is likely to be a walled garden DMZ designed for quarantined BYOD remote access where BYOD devices connect much like guests but have the ability to access remote access resources like RDP, ICA or PCoIP protocols.  VLANs would also be popular for building traditional DMZs for externally facing public services such as web and email servers – except that these services are not commonly kept on the local network for hosting in today’s SMBs so this classic use of VLANs in the SMB is rapidly fading.

Another use case where VLANs are often used inappropriately is for a Storage Area Network or SAN.  It is best practice that a SAN be a completely independent (air gapped), physically unique network unrelated to the regular switching infrastructure.  It is generally not advised that a SAN be created using VLANs or subnets but instead be on dedicated switches.

It is tempting to add complex switching setups, additional subnets and VLANs because we hear about these things from larger environments, they are fun and exciting, and they appear to add job security by making the network more difficult to maintain.  Complex networks require higher end skills and can seem like a great way to use that networking certificate.  But in the long run, this is a bad career and IT strategy.  Network complexity should be added in a lab for learning purposes, not in production networks.  Production networks should be run as simply, elegantly and cost effectively as possible.

With relatively little effort, a small business network can likely be designed to be both physically and logically very simple.  The goal, of course, is to come as close as possible to creating single, flat network structure where all devices are physical and logical peers with no unnecessary bottlenecks or protocol escalations.  This improves performance and reliability, reduces costs and frees IT resources to focus on more important tasks.

Originally posted on the StorageCraft Blog.

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Four open source invoicing tools for freelancers and small businesses

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invoice, delicious invoiceNote: This post was originally published on September 2, 2014 at Opensource.com.

Small business owners and freelancers put a lot of work into their businesses. They do that not only because they’re passionate about what they do, but they also have the goal of getting paid.

That’s no small part of the job, either.

Getting paid usually means sending a client an invoice. It’s easy enough to whip up an invoice using a word processor or a spreadsheet, but sometimes you need a bit more. A more professional look. A way of keeping track of your invoices. Reminders about when to follow up on the invoices that you’ve sent.

There’s a wide range of commercial and closed-source invoicing tools out there. But the offerings on the open source side of the fence are just as good, and maybe even more flexible than their closed source counterparts.

Let’s take a look at four open source invoicing tools that are great choices for freelancers and small businesses on a tight budget.

What to look for in an invoicing tool

Not all invoicing tools are created equally. Some, depending on their developers and their maturity, may have more or fewer features than most. But at its core, a good invoicing application has all or several of these features:

It should be accessible on the web. That can be on your own website or, if you lack the technical chops to install and maintain the tool, then it should have a hosted version.

It should also let you easily customize invoice templates to get the look and feel that you want. On top of that, the tool should have a either a reporting feature or the ability to save your records to a spreadsheet.

The tool should support multiple currencies and allow you to configure your local tax rates. Supporting multiple languages is a bonus.

Finally, the tool should be able to accept payments via PayPal or a payment service like Stripe. If it doesn’t so that out of the box, it should be easy to add that integration.

Simple Invoices

While it’s name contains the word simple, Simple Invoices isn’t a barebones application. Far from it. Simple Invoices is easy to set up and use, but packs a number of useful features. Not only does it accept payment from PayPal but you can also hook Simple Invoices into a payment gateway called eWAY.

Simple Invoices goes beyond invoicing. It can also track your inventory, create receipts, estimates, and quotes. You can save your invoices as PDF, Word, Excel, or text files.

Before you download and install Simple Invoices, you can give it a try. You can also use one of the hosted versions from $4 a month and up.

Invoice Ninja

Invoice Ninja melds a simple interface with a powerful set of features that lets you create, manage, and send invoices to clients and customers. You can easily configure multiple clients, track payments and outstanding invoices, generate quotes, and email invoices.

What sets Invoice Ninja part from its competitors is that it supports over 20 popular internet payment processors, including PayPal and Google Wallet.

Download a version that you can install on your own server, or get an account with the hosted version of the tool. There’s a free version and one that will set you back $50 a year.

siwapp

It’s not the slickest looking tool, but siwapp compensates for that by making it easy to create professional-looking invoices. Just enter information into a few fields and, when you’re done, click a button to email the invoice.

siwapp also comes with a trio of modules that let you create and manage customer records, estimates, and products. On the other hand, out of the box siwapp doesn’t come with integration with a payment processor. If you’re a dab hand with PHP, you might be able to hack siwapp and include a payment link, as one user did for PayPal.

You can test drive siwapp before you decide to install it.

Open Source Billing

Described by its developer as Beautifully simple billing software, Open Source Billing does live up to the description. It has one of the cleanest interfaces you’ve seen, which makes configuring and using the tool a breeze.

Open Source Billing stands out because of its dashboard, which tracks your current and past invoices, as well as any outstanding amounts. That information is broken up in to graphs and tables, which makes it easy to follow.

You do much of the configuration on the invoice for itself. You can add items, tax rates, clients, and even payment terms with a click and a few keystrokes. Open Source Billing saves that information across all of your invoices, both new and old.

As with some of the other tools we’ve looked at, Open Source Billing has a demo that you can try.

Photo credit: neiltron via PhotoRee

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Bogdan Mustiaţă: SSHD Cygwin HowTo

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Start Cygwin as an Administrator, and then run:

# ssh-host-config -y

Follow the instructions on the screen.

Finished.

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This brick could save Californians 67 million gallons of water a day

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dropabrick

This is part of a series of articles that looks at entrepreneurs hoping to get their ideas off the ground through crowdfunding. At the time of writing, each of these innovations is currently seeking funding.

California is facing one the worst water droughts in history, and with many towns facing problems with water resources the importance of being thrifty is becoming very clear. We’ve already written about Everydrop LA, the app that enables citizens to report instances of water leakage in the city. Now another project is encouraging Californians to Drop-A-Brick into their toilets to save water and money at home.

It’s a common piece of advice that has been passed down through the ages — put a brick in your cistern to save water. Currently seeking funding through Indiegogo, the project is simply getting people to do just that. The nonprofit has created a rubber alternative to the standard brick, which can often end up damaging toilets. The Drop-A-Brick on the other hand is soft, using a hydro-gel that react with water to give it the weight to sink rather than float. Because it’s flexible, it can fit into any space in the cistern, unlike actual bricks. When in place, the nonprofit says it saves about half a gallon of water with each flush. If every citizen of Calfornia installed the Drop-A-Brick in their bathroom, they could help save up to 67 million gallons of water every day.

Watch the tongue-in-cheek video below, which acts as a promo for the campaign:

Backers can support Drop-A-Brick’s Indiegogo campaign until 31 October, where they can purchase their own bricks or donate them to households in need from as low as USD 15. As well as helping the environment and maintaining water resources for more important things such as drinking and plant water, homeowners could also cut their water bills using the low-tech device. Are there other ways to rethink time-tested, low tech methods to ensure they’re effective for everybody?

Indiegogo: www.igg.me/at/dropabrick
Website: www.dropabrick.org
Contact: www.facebook.com/project-drop-a-brick








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Moon-landing conspiracy claim refuted by video game graphics

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THE VEGETABLES OF TRUTH

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vegoftruth

This is really just an excuse to show a wonderful film about vegetables.

But it is also about how modern science has radically changed in a way that hasn’t been fully understood.

How it has gone from promising extraordinary new worlds of the future - to become a powerfully conservative force that holds progress back and tends to keep people in their place.

And the odd role vegetables have played in showing how this has happened.

Veg2

There are two - parallel - universes of science. One is the actual day-to-day work of scientists, patiently researching into all parts of the world and sometimes making amazing discoveries.

The other is the role science plays in the public imagination - the powerful effect it has in shaping how millions of ordinary people see the world.

Often the two worlds run together - with scientists from the first world giving us glimpses of their extraordinary discoveries. But what sometimes happens is that those discoveries - and what they promise - get mixed up with other social and political ideas. And then the science begins to change into something else.

This happened in a dramatic way in the second half of the twentieth century. Science did very well in the second world war and after the war ambitious scientists promised they could build a new kind of world.

But by the 1970s it became clear that there were unforeseen consequences. It started with chemical pollution - especially DDT killing wildlife. But it was nuclear power that really broke the faith in the optimistic view of science - with the disaster at Three Mile Island in the US in 1979.

What emerged instead was a powerful distrust of the idea that science and technocratic experts could make a better world. Here is a good example of that new mood. It’s an anti-nuclear rally held in New York after Three Mile Island.

Jane Fonda makes a celebrity appearance - and her interview articulates the mood very well. I also love the protest song at the end.

“Just give me the restless power of the wind

Give me the comforting glow of the wood fire

But please take all your atomic poison power away”

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But if the scientists had been naive - so too was much of the counter-reaction.

The truth was that it might not have been the science itself that was at fault - but the way the science had been distorted and corrupted by the economic and political demands made on it.

Here is a section of a film I made about what went wrong with the building of the first big nuclear reactors. It shows how the companies building them - like General Electric - were under enormous economic pressure and political demands because of the cold war. And the technologists designed giant systems they knew were potentially unsafe.

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Then came the Chernobyl disaster in 1986. All the distrust of big science that had been building up exploded out - and science became the problem. Not the solution any longer.

There was one man who articulated this new view of science very powerfully. He was a German political scientist called Ulrich Beck who wrote a book just before the Chernobyl explosion called Risk Society. In the wake of the disaster it captured the public imagination - and has been incredibly influential on social and political thinking in the west ever since.

beck

The book was powerful because it laid out a new way of looking at the world. Beck said that what the scientists and technologists had been doing with these giant projects was not building a new and glorious future. Without realising it they had been doing the opposite - they had been creating enormous new dangers for the world.

Beck used the word risk. The scientists he said had been “manufacturing risks”.

In the past the big risks to human societies tended to be freak events of nature - like earthquakes and volcanoes and storms. But now the risks came from human ingenuity and ambition. Much of what had been created had potentially world-threatening side effects - like atomic fallout and ecological disasters.

The world had been turned upside down. It wasn’t nature that was the real threat to human existence any longer - it was now human science and technology that had the power to destroy nature and the whole of the planet. And it wasn’t going to stop - this was a new and growing danger.

It meant - Beck said - that the whole role of politics would inevitably change. In the past politicians’ main aim had been to create a more equal society. That was now in decline. In the new “risk society” their main focus should be to create safety.

Beck didn’t mince his words:

Whereas the utopia of equality contains a wealth of substantial and positive goals of social change, the utopia of the risk society remains peculiarly negative and defensive. Basically, one is no longer concerned with attaining something ‘good’, but rather with preventing the worst.

The dream of the old society is that everyone wants and ought to have a share of the pie. The utopia of the risk society is that everyone should be spared from poisoning

That was written in 1986 - and it is remarkably prescient. Because that short paragraph pretty much describes the present day mood in our society. A world where individuals are constantly calibrating risks in their lives, while politicians are expected to anticipate and avoid all future risks and dangers.

And everyone gives up on the idea of creating equality, which allows inequality to increase massively.

Beck’s book is extraordinary - because he came from the liberal left. Yet he is basically saying that in the face of these new potential risks we will have to move away from the political idea of progress and social reform - and instead hunker down in the brace position and try and anticipate all dangers that might be coming at us out of the darkness.

To be fair to Beck he is ambiguous in the book about the kind of pessimistic and anxious society that will arise from this new approach. But he says it is inevitable. And in a way it is a very honest depiction of what happened to the liberal mind set at the end of the 1980s - how it retreated into a gloomy pessimism where the only response to events is “oh dear.”

I think the truth probably is that it was the baby boomers losing their youth - and finding themselves unable to face the fact of their own mortality - they started to project their fears onto the rest of society. But somehow people like Beck transformed this into a grand pessimistic ideology.

risk

I want to put up part of an extraordinary documentary made during the events of 1986 that dramatically shows just how different our attitudes to risk used to be. It is the record of the group of Soviet technologists who volunteered to go into the ruined reactor core at Chernobyl after the disaster.

It is extraordinary because they all knew they would die. Their protection against the radiation - as you see in the film - was minimal. It consisted of taping up their cuffs and trouser legs and not much else. But they went in because it was the only way to find out how to contain the disaster.

It is so moving because they are men from an older world. To them risk is irrelevant. They believe in something grander - bigger than their own lives. There is also the most fantastic remote controlled camera - it is mounted on a toy tank and its images are great.

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The idea of the Risk Society gave modern science and technology a real kicking. Because they were the ones - it said - who were mainly creating the risks.

But it also allowed science to invent a new role for itself. Because a new breed of scientists came forward and said that they knew how to analyse the dangers - and anticipate the risks. They wouldn’t try and build dazzling new futures, instead they would keep the world safe by spotting the dangers before they arrived.

It was the beginning of a modern science which now permeates the modern world and whose full dimensions I don’t think we’ve fully recognised. It has become central to all sorts of areas - from medicine and public health, through climate change, finance and the welfare state - and even to the anticipation of terrorism and crime.

What the scientists and technologists do is look for patterns, associations and correlations in large amounts of data. It has permeated the public imagination mostly through the regular reports that find associations between diseases and human behaviour. Journalists love them - the one I particularly liked was the scientific report that said that snoring gave you cancer.

snoring

But this science does have powerful roots. It was just this kind of search for correlations that allowed scientists to prove that there was a link between smoking and cancer. It was a piece of scientific investigation that changed the world - and has saved millions of people from an early death.

It was work like that which has allowed modern science to rise up in a different form - and again become central to society - because now it was warning us of the dangers. Which is good.

But there is a weakness in this scientific approach that can allow it to be shaped and manipulated by wider social and political forces.

This is because if you look for correlations you often have no real idea of why something is happening - just that it is somehow associated. The warning phrase is “correlation does not mean causation.”

The scientists know this very well - and they constantly try and cross-check to see if the correlation is real or spurious by accounting for all sorts of variables. They look for hidden factors that might really be the reason for something happening and try and adjust the data for these. They have a good name for these hidden factors - “residual confounders.”

But the problem is that they are always trying to imagine what the hidden variables are - and the choice of what you do imagine and what you don’t is inevitably shaped by wider social and political views of the world.

Which bring us to the vegetables.

Seven months ago a scientific report came out that illustrates this danger very clearly.

It was from University College London and it said said that people who eat seven or more portions of vegetables every day - rather than the recommended five - live longer. And it wasn’t just a little bit longer, one of the authors of the report said that the effect was “staggering.”

The claims were powerful. It said that if you ate up to five portions a day it would reduce your risk of death by 29%, but if you ate seven or more portions the risk was reduced by 42%

As a result the report got a lot of publicity - with people arguing that the national guidelines ought to be changed. Here’s some of the TV and newspaper coverage.

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But if you look into the report, two rather surprising things emerge.

First that the data is not really strong enough to support the confident conclusions of the researchers. It is, as one scientist not connected with the report told me, far more a leap of faith than a scientifically proven conclusion.

And secondly the scientists who did the research may have ignored another - and very different - conclusion that the data might point to. This is that if you want to live longer you should change society.

To do the report, the researchers had taken data from the Health Surveys of England. Every year a random group of people are asked questions about their lives - and one of the sections asks them how much fruit and vegetables they have eaten in the past twenty four hours.

The researchers took the answers from one of those surveys twelve years ago and compared the fruit and vegetable answers with who had died over the past twelve years. And that is basically it. The report was based on what sixty-five thousand people said they had eaten on one single day a long time ago.

I asked Professor Tom Sanders, who is Professor of Nutrition at Kings College London, about the research behind the report.

He was pretty scathing. The data was dubious he said - because there is no way of finding out if the respondents had lied. He had a good line - “Men lie about smoking. Women lie about vegetables”.

But far more importantly, he said, was the fact that they might have misinterpreted the data. That the reason that some people in the survey live longer may not have anything directly to do with eating more vegetables. It might be that eating more vegetables is the sort of thing people higher up the social scale do.

And people in higher social classes tend to live longer - because of all sorts of other factors, like access to better health-care throughout their life, less stress, living in nicer neighbourhoods with less pollution. All the kinds of things that you tend to get if you have more money and more freedom.

I pointed out to Professor Sanders that the researchers said in the report that they had “adjusted the data for social class”. But he was dismissive of this - saying that the data they used to do this was “incredibly weak” and at times non-existent.

And if you read the report, buried away is an admission that one of the most dramatic correlations - that people who eat canned rather than fresh fruit die much earlier - might be due to some other factor completely.

quote admission

There is absolutely nothing wrong with eating healthily. And it is very sensible to eat fruit and vegetables regularly.

But something else is going on here. The scientists behind the report are playing on our anxieties and saying you must eat even more healthy food so as to avoid dying early. When in fact the data might be pointing to the very opposite.

That the way to avoid dying early is to reform and restructure society so poor people have more access not just to better food - but to all the kinds of opportunities that richer people do. These are a range of social factors from health care and housing and education to social isolation, stress, unemployment, and higher-risk occupations. These are the sorts of things that also affect how long people live.

To lump it all onto vegetables is unfair.

Science and scientists do all kinds of wonderful things. But when they venture into the social and political world they tend to get bent the way the ideological wind is blowing.

Once it was to support politicians trying to expand their power by remaking society. Now - in an age of individualism - it is to keep us in our place by promoting the idea that we should just focus on ourselves and our bodies. And not think about the wider problems of growing inequality and the unfairnesses that brings.

The scientists are saying - just go and eat another banana or cabbage and you’ll be alright. They are loading everything onto the isolated individual.

Such reports - and there are many - keep us locked inside the anxieties of the “risk society”. While the truth is that you might have a better chance of living longer if you banded together and used that collective power to change society. It would also be a lot more fun than laboriously counting vegetables.

As an antidote - here is a beautiful film about vegetables. It’s a documentary made in 1972 about a leek-growing contest in Newcastle. It is very camp - with lots of men discussing the length and diameter of their leeks.

It is also all about statistics and numbers - because it is the measurements that will decide the winner. But in this case it’s not about the fear of death. It’s all about pride and glory in the vegetables - among men who lead the unhealthiest of lives. Constantly smoking and drinking as they talk about their beloved vegetables.

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afita
12 days ago
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Did you have your 7th portion of leek today?
Cluj-Napoca, România
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