Quick Update for Virgin Media Speed Issues on IPv6 Tunnels
Customers awaiting a firmware update from Virgin Media UK to fix the throttling of broadband speeds on IPv4 internet traffic – specifically when data packets carry Protocol 41 (i.e. the IPv6 encapsulation / tunnel protocol) – may be unhappy to learn that there’s still no ETA, despite the issue being acknowledged 8 weeks ago.
The problem itself (here) is admittedly somewhat niche because it only impacts those who have tried to get an IPv6 internet address (Virgin Media have yet to add their own native support) by harnessing a 6in4 tunnel service via Protocol 41 (IPv6 encapsulation), which works with a third-party service (e.g. Tunnel Broker) to embed IPv6 packets inside IPv4 packets.
Normally this would work fine via any other ISP but, on Virgin Media’s network, customers with one of their HUB 3.0 (SuperHub v3), Hitron or older routers (the latest HUB 4.0 isn’t affected) found that download speeds were dropping to around 20Mbps, although it took over a year to finally get the operator to acknowledge this problem.
Several customers have since asked us to nudge the operator for an update, which occurred partly because some users have become frustrated with the lack of updates. The bad news is that not much has changed since last time, although they do now clearly acknowledge the issue rather than merely “investigating” it like before.
A Virgin Media Spokesperson told ISPreview.co.uk:
“We are aware of an issue which affects those customers who choose to use 6in4 IPv6 tunnels. This will be fixed in a future firmware update. We’re in the process of finalising our plans for IPv6 deployment and will provide an update at the appropriate time.”
Virgin aren’t the fastest when it comes to issuing firmware updates for tedious bugs and in fairness part of that can sometimes be down to delays on the manufacturer’s side (ARRIS for the HUB 3.0). Likewise, they’ve been in the process of preparing their IPv6 plans for some years now, as such we’re no longer sure which will come first – their IPv6 rollout, a fix for the 6in4 tunnels bug or universally available gigabit broadband.
Mark is a professional technology writer, IT consultant and computer engineer from Dorset (England), he also founded ISPreview in 1999 and enjoys analysing the latest telecoms and broadband developments. Find me on X (Twitter), Mastodon, Facebook and Linkedin.
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I know the race is on for IPv6 but has anyone clever here got any info on how many IPv4 addresses are currently unused and held by corps and govs waiting for big profits on landgrabs made years ago for peanuts? just askin.
Even if you could release IPv4 ranges somehow the issue really is that providers, particularly mobile, should simply get IPv6 to work properly as intended and stop spending time on nonsense such as CGNAT. IPv6 is over 20 years old and if they were still hesitant it has still been 3 years since it was ratified. So in my view they have all had long enough.
Okay. How about sites that have no IPv6? There are still plenty?
Only about 30% of our flows are IPv6.
IP addresses are released on an ongoing basis. It’s astonishing still that there are companies with nearly 5% of the entire IPv4 address space who use virtually none.
How many addresses are unused? Not enough to avoid the need for IPv6. Just answerin.
Websites without v6 aren’t a problem; they can be reached easily via NAT64. The problem is clients without v6, since they prevent people from setting up websites without v4.
Yep. 4-in-6 will have to be done for a while, or DS-Lite. My point was more aimed at Meadmodj’s dislike of CG-NAT.
NAT is inevitable during transition sadly. DS-Lite with 1:1 mapping between 6 and 4 will work fine, behind CG-NAT not so well though of course dual-stack is optimal.
I do understand why we needed CG-NAT its just that it introduced significant drawbacks and encouraged short term investment based on the address issue rather than the other benefits IPv6 provides.
Kings college has thousands of IPs
Cambridge has thousands of IPs
actually most universities do. they’ve got no need for them at all.
I do wonder though who wants to run IPv6 on virgin media, and why? presumably it’s just hackers / network geeks like us running a tunnel from hurricane electric. I’d hardly say it’s a big issue and it would be better if they focused on actually brining out IPv6.
https://ipv4.potaroo.net/
Figure 5 shows the proportion of IPv4 address space which is not currently being advertised, in orange.
Also, even though a range is being advertised, doesn’t necessarily mean it is all used.
A place I worked at used a public /24 for a very sensitive internal network. The /24 was blackholed on the net and firewalled internally for access by specific internal hosts in specific zones, routed to null again elsewhere.
I thought it was over kill, they felt it was more secure, I pointed out that rfc 1918 or BOGON addressing would have done much the same, but some people are set in their ways and believe in myths etc.
A later work place had a /16 used internally as that was how things where done 30 odd years ago. Management decided to sell the address space to an isp, suddenly some of the “customers” had issues connecting to that places systems, lots of anti spoofing errors etc etc etc.
If we’d re ip’d everything to rfc 1918 it wouldn’t have been an issue, but how do you migrate ~30 years of implementation across 10’s of thousands of devices over night, answer is you don’t. It’s not just giving everything a new ip, policies need changing, rules need updating, documentation needs fixing, that critical system that someone built in some obscure language who is no longer around needs updating etc etc etc.
The need for legacy is what will keep ipv4 around for a longtime to come.
It’s interesting. At this point you’d think Virgin Media would just aim to deploy native IPv6, solving two problems, rather specifically focussing on 6in4 given it’s niche use. Don’t get me wrong, I’m on the people that’s been vocal about it, but I gave up and decided to use AAISP L2TP for a static IPv6 prefix. While it is still a tunnel, it is native IPv6 over 6in4 at least but at an extra cost.
Be interesting to know if their IPv6 plans are still DS-Lite or if they decided to go the way of Sky and BT and do full dual stack.
“it is native IPv6 over 6in4 at least but at an extra cost.”
I should have said, “native IPv6 compared to 6in4”.
Could this be the reason I can’t get onto multiplayer with the Xbox app on pc while it works fine on a stand-alone X box? I’ve tried everything else!
I use it in modem mode and have a good router will this affect me
If you don’t use an IPv6 tunnel or have never configured 6in4. No, you don’t need to worry.
However if you do use a 6in4 tunnel it’ll affect you even in modem mode.
Bit of a minimal update indeed…
I heard on the grapevine that they’ve basically put their v6 deployment on hold due to some shuffling of their business that means they “have enough v4 addresses now”. That doesn’t quite agree with the quote in the article, but their spokesman has been claiming “real soon now” for at least half a decade so I’m not sure their official position has anything to do with reality.
Rumour has it they ditched DS-Lite, but nothing public about it since 2018 after their IPv6 trials in the summer and IPv6 council appearance in December of the same year.
Thanks for prodding VM for an update. I don’t hold out much hope of seeing a firmware update for my SH3. Probably be cheaper just to give affected customers upgrades to SH4. SH3 really is teh gift that keeps on giving…
I wonder if this is due to Intel’s ‘fix’ for the Puma 5 chipset bug?
I long suspected they moved some packet processing off the ASIC and onto a slower path that didn’t hit the same issues with latency spikes.
This does sound very un-hardware accelerated. VM did have big plans to launch V6 but it seems to have gone quiet. Any updates @mark?
Having spent a lot of time with a SH3 and trying to debug this and other behaviour it’s not just IP41, and there won’t be a fix. As above it’s the ‘normal’ puma 6 hardware bug unfortunately.
Anything non-TCP will cause this and worse effects, the latency spikes are a far worse aspect.
I went from a SH2 to a year of frustration with a SH3 before being ‘lucky’ enough to be able to change for a SH4 where all the previous issues evaporated. Smokeping graphs from before vs after are night and day.
They’re going to give it lip service and nothing more I’d imagine as it’s not really possible to fix per say and most of their customer base won’t know they’ve got a problem, outside of it pros/enthusiasts it’s the gamers it hits the hardest.
It sounds like the hardware in the Hub4 seems to fair better with this, but I do wonder about VM Business. As far as I know there isn’t a new router/modem of the current Hitron, so are VM business stuck for now? Will there be a Hub4 business equivalent?
I did a lightning talk about this last year at the North American network operators group. It’s not supported by the hardware ASIC, so the anemic CPU has to handle the traffic – which it’s really bad at. See https://pc.nanog.org/static/published/meetings/NANOG76/2045/20190611_Van_Mook_Lightning_Talk_Ipv6_v1.pdf
That’s what has been theorised for a while, it good to hear it from someone who clearly knows about this kit. If that is the case and it’s a hardware problem, how can it be fixed by a firmware update?
It’s a niche issue, so I’d just give affected customers SH4s and forget about it.
Just look at very end of article where is “Cheapest Superfast Broadband ISPs:”.
Super fast and offers are from 36 to 66Mbps !!! ISP’s won’t fix anything but sell crap slow connection for highest price as possible.
We have phoned Virgin several times regarding poor broadband service when we’re paying in excess of £100pm for a service which is inadequate.
I’m gonna go out on a limb here and say virgin media will go out of business before it switches to ip6.
I was talking to the broadband specialist regarding the Puma 6 issues but he brought this one up too.
He did tell me that this has already been fixed but won’t be in the upcoming patch and expected sometime next year.
Since Virgin announced their 1Gig service is now available in London my IPv6 via HE no longer has the 20Mb cap (using SH3). Am I alone?