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Plusnet customers share IP addresses


By Nicole Kobie

Posted on 15 Jan 2013 at 13:50

Plusnet is testing a system to share IP addresses as it looks for solutions for a looming IPv4 shortage.

IPv4 is the current numbering system for issuing IP addresses, but it's running out of space. However, some ISPs aren't ready to switch to IPv6 and some devices don't support the new version.

As a stop-gap solution, Plusnet is running a three-week trial in which volunteer customers will share IPv4 addresses, rather than each having their own.

Plusnet will use a Carrier Grade Network Address Translation (CGNAT) system, and is looking to find out what apps, services and devices cause trouble. It won't allow customers to host websites or servers, and is expected to cause issues with games.

"Carrier Grade NAT (CGNAT) is similar to the NAT that people use on their home routers," the post on Plusnet's support forums says. "The NAT on your home router lets all the devices on your network (PCs, tablets, phones, consoles etc.) share one IP address."

"What CGNAT does is take that a step further and has several customers sharing one IP address," the post adds. "For most people they will never notice, most mobile operators already use CGNAT and so most applications will just work. The main problem is where you are hosting services on your broadband connection like hosting a website or hosting games (the kind of thing for which you set up port forwarding on your router)."

Plusnet is currently looking for customers willing to test the system, and the trial is set to start at the end of the month.

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User comments

Demand all ISPs move to IPv6!

Tell the Daily Mail and certain MPs that this is good for Bad People. After all it's going to be that much harder (if not impossible) for the police to identify a suspect from server logs of IP addresses.

Move to IPv6 now! Only Terrorists and paedophiles use IPv4! Think of the children!

By TBennett on 15 Jan 2013


Why not just move customers over to IPv6 who can support it?

This looks like a lack of investment by Plusnet (which is now owned by BT). It is not as though they did not know this was coming!

By bernardm3 on 15 Jan 2013

Pure IPv6

Over here, Telekom moved to push new customers taking their DSL/VOIP package (i.e. no telephone line, just data) to IPv6 only last year.

By big_D on 15 Jan 2013



I can see the headlines now:

By TheHonestTruth on 15 Jan 2013

Terrorists and paedophiles use IPv4

I think Terrorists and pedophiles that use IPv4 are not bothered what technologies are used, in fact I think the only group that will be worried are those organizations who go after file shares, music vendors and porn suppliers, they are the ones who will be blocked from knowing who "owned" that IP address at that moment in time.

"This looks like a lack of investment by Plusnet (which is now owned by BT)"

This will save the ISP's huge sums of money in legal fees in court costs having to reveal who was using that IP address at that time of "infringement", lets face it is you use IPV6 technical measures can be put in place if you are so inclined to hide your IP address from that sort of monitoring.

By Chrisfjr1300 on 15 Jan 2013


So... you agree with TBennett then (as you've just rehashed his point, sans the humour).

By TheHonestTruth on 16 Jan 2013


The point I was I was trying to make, I think Plusnet are sharing IP address to stop them having to reveal who was using that IP address to content owners as they can argue "we don't know who was using that IP address at that"

By Chrisfjr1300 on 16 Jan 2013

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