Major technical problems could become a regular occurrence for website users because the internet is running out of space, experts have warned.

An online breakdown caused chaos on Tuesday, costing the economy millions of pounds in lost trade and effectively closing access to a number of huge websites.

Online auctioneer eBay was out of action for most of the day, with buyers and sellers inundating the site with complaints about lost business after being unable to log onto their accounts.

An online breakdown caused chaos on Tuesday, costing the economy millions of pounds in lost trade and effectively closing access to a number of huge website (file picture)

Hundreds of thousands of users were unable to log on and the auction site was flooded with traders demanding compensation.

The problem is understood to have been caused by the crucial ‘nuts and bolts’ of the internet – called the Border Gateway Protocol (BGP).

Internet companies and large networks use this ‘route map’ - consisting of hundreds of thousands of complex paths through the web - to send information to each other.

When visiting a website, users rely on machines called routers to remember how to navigate trusted routes through the ever-expanding internet.

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What caused this issue? As traffic travels around the internet, it's directed by routers which know where to send individual packets on the basis of a 'lookup table.' This table has groups of IP addresses to help direct traffic to the right places, like postcodes in a sorting office.

The number of groups of IP addresses that can be held in the very fast type of memory required for this job is limited to 512,000 in some routers.

Once this number is exceeded, those routers stop working properly. The cause of this issue was that a major American networking company took one large group of IP addresses and split it into 15,000 smaller groups. This took the total number of prefixes (packets of IP addresses) from about 500,000 to 515,000 so this pushed past the limit and meant that routing stopped working in parts of the US.

This was fixed in about 10 minutes but it still caused significant disruption to internet users and some major sites like eBay.'



Why were eBay and Amazon affected in particular?

People take more notice when these high profile sites go down. Many more sites would have been affected, they just weren't as noticeable. ' We were always going to hit this limit, the prediction was that it would happen by October.

Cisco, one of the world's biggest manufacturers of routers, notified all of its customers of this potential issue back in May. It's possible that internet service providers (ISPs) thought they still had more time before this would become an issue. Will it become more widespread? Will more websites be affected?

The limit will certainly be reached again.

Whether or not the web is brought to its knees depends on how many network providers make the necessary upgrades before the limit is reached permanently. IPv4 exhaustion is contributing to this problem because as IPv4 resources get more limited they are handed out in smaller groups which makes the number of prefixes increase.

So the very slow take-up of IPv6 is having an indirect effect on the speed with which we hit this limit, and the likelihood of this issue happening again soon.



What will happen if everyone does nothing, and will the situation get worse?

'If this problem isn't fixed, we will see a catastrophic repeat on a much larger scale. This news might act as a catalyst for networking companies to act, but their track record on updates is far from encouraging.

But older routers are finding it difficult to manage with newer technology – such as smartphones and tablets which have drastically increased the number of people online and the time spent online.

They have imposed a huge volume of extra traffic onto the web, leaving some routers struggling with lack of memory and processing power.

Some machines impose an arbitrary upper limit of 512,000 different routes, a number that experts say is out of date.

The system is similar to the human brain being unable to cope with remembering ‘all the back streets’ on a long car journey, said Dr Joss Wright, a research fellow at the Oxford Internet Institute.

Online auctioneer eBay was out of action for most of the day, with buyers and sellers inundating the site with complaints about lost business (file picture)

In order to deal with the increase in web traffic, routers need to be updated with more memory and processing power.

But experts said some machines are starting to become badly dated.

Dr Wright told The Daily Telegraph: ‘It’s really a case of the routers being overloaded due to more and more devices and more and more fragmented Internet landscape of lots of little networks.’

James Gill, chief executive of Internet traffic monitoring firm GoSquared, said: ‘This is likely to happen more and more the devices there are and the less the infrastructure is going to be able to cope. This definitely won’t be the last we hear of BGP outages.’

Weekly Internet retail sales averaged £729 million in June - meaning more of these problems could see online retailers losing millions of pounds of trade in the future.

Richard Perks, from the market analysts Mintel, said: ‘Online firms build up their reputations on trust, on delivering a flawless experience to their customers.

‘If such problems become a regular feature, then that is a serious problem both for firms and for the economy in general.’