IPv6 support on Virgin media

[dgcarter]

Does anyone know whether (and if so when) Virgin plan to implement IPv6 on its network?

[ChrisJenkins]

Um yes, I only checked a week or two ago and at that point they hadn't. But now they have it seems.

Great!

[Optimist1]

Interesting to see the progress of IPv6 adoption over the whole world since this thread started. https://www.google.com/intl/en/ipv6/statistics.html

[ChrisJenkins]

So IPv6 is approaching 50% utilisation, which means that IPv4 and IPv4 now have similar usage overall. Doesn't quite gel with Virgin Media's assertion that there is no demand for it... 🙂 

[VMCopperUser]

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@ChrisJenkins wrote:

So IPv6 is approaching 50% utilisation, which means that IPv4 and IPv4 now have similar usage overall. Doesn't quite gel with Virgin Media's assertion that there is no demand for it... 🙂 

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They view their network stats regularly.  0% of their customers are using IPv6.  Seems to me that they are correct, VM customers have no real demand for it.  Plus as they have said in the past.  They have enough IPv4 to share around!

I have to agree that it does seem odd that they are not moving forward.  You would think that new customers would be moved onto a IPv6 enabled system by now and that "Legacy" customers would migrate over slowly, but the rate they are going means the whole kitty will need to be swapped at the same time - and that will be messy I rekon!

[jamesmacwhite]

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@VMCopperUser wrote:

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@ChrisJenkins wrote:

So IPv6 is approaching 50% utilisation, which means that IPv4 and IPv4 now have similar usage overall. Doesn't quite gel with Virgin Media's assertion that there is no demand for it... 🙂 

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They view their network stats regularly.  0% of their customers are using IPv6.  Seems to me that they are correct, VM customers have no real demand for it.  Plus as they have said in the past.  They have enough IPv4 to share around!

I have to agree that it does seem odd that they are not moving forward.  You would think that new customers would be moved onto a IPv6 enabled system by now and that "Legacy" customers would migrate over slowly, but the rate they are going means the whole kitty will need to be swapped at the same time - and that will be messy I rekon!

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Don't forget it was discovered a while back there is fact IPv6 live on the WAN side right now and has been for some time, based on conversations with Liberty Global network engineers. Router Advertisements for IPv6 prefixes are still there and there is routable IPv6 address space when you configure it manually, given DHCPv6 requests are ignored/dropped. Whether or not this just still left over from the DS Lite trials or something else, anyone's guess. This of course is not intended to be messed with, but it remains visible if you do some tcpdump commands on the wire targeting the WAN side, so we can at least say the network has IPv6 active, just not entirely live on the customer side, which I would imagine is being purposefully being hidden. Although, I remember when people tested this, it wasn't showing up everywhere, but I have no idea if that's purely down to location or otherwise.

The Hub3 (can't comment on Hub4/5) still has the IPv6 DS Lite config present hiding away, just inactive. I'd imagine any IPv6 rollout would require some form of firmware update for whatever Hub models support it. I'd guess a baseline maybe Hub3 and up for IPv6, but it's purely down to their network and what they ultimately choose to use, just hopefully not DS-Lite. My thoughts at this point if it was DS-Lite it would have been done by now given it's basically live in every Liberty Global owned network across Europe, except for the UK. The lack of this, suggests Virgin Media reconsidered, possibly from the trials or maybe influenced by the fact that their major competitors went dual stack.

On the having enough IPv4, I'm pretty sure early on in the Liberty Global acquisition, Liberty Global raided Virgin Media's IPv4 for some of their networks. They might still have some, I'm not sure it's "plentiful" anymore. Probably worth a bit of money though if they sold it off though!

[TonyHoyle]

It's good to read this thread every couple of years, it's like an old friend..

Anyway I've just upgraded to gigabit and after a series of network upgrades that cost £<don't tell the wife> I can speed test at around 1.1/1.2Gbps.  Yay.

But the HE tunnel I have caps out at around 400Mbps.. I wouldn't expect a 60% overhead.. are VM still doing silly things with tunnels?

[jamesmacwhite]

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@TonyHoyle wrote:

It's good to read this thread every couple of years, it's like an old friend..

Anyway I've just upgraded to gigabit and after a series of network upgrades that cost £<don't tell the wife> I can speed test at around 1.1/1.2Gbps.  Yay.

But the HE tunnel I have caps out at around 400Mbps.. I wouldn't expect a 60% overhead.. are VM still doing silly things with tunnels?

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Sometimes it can vary, for a variety of reasons, in some cases some of the POPs on HE's end could be particularly over utilised reducing speed as there is no SLA, however considering you can only get around 15-20 Mbps max when CPU bottlenecks on Hub3 and below, 400 Mbps isn't that bad to be honest. Sure you aren't getting your full speed like IPv4, but then you're not running native IPv6 either, trade off. 60% is certainly not just overhead though, there's other factors causing that, which you probably can't really control and it will probably change tomorrow.

The official response from Virgin Media is they've never done anything specific to limit speed with 6in4 so they aren't doing "silly things", even Liberty Global engineers confirmed that there is nothing like QoS or speed capping going on after we kicked up enough of a noise, they couldn't find any issues in the network that reproduced the poor performance, so the CPE hardware was deemed the issue and indeed over time it appears that 6in4 is heavily tied to CPU and all of CPEs prior to the Hub4 didn't handle it well at all. The Hub4 by chance doesn't have the same issue mostly down to a more powerful CPU (although it's still that god awful intel Puma architecture) and the Hub5 being also more powerful and not Intel Puma fairs much better.

[ChrisJenkins]

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@TonyHoyle wrote:

It's good to read this thread every couple of years, it's like an old friend..

Anyway I've just upgraded to gigabit and after a series of network upgrades that cost £<don't tell the wife> I can speed test at around 1.1/1.2Gbps.  Yay.

But the HE tunnel I have caps out at around 400Mbps.. I wouldn't expect a 60% overhead.. are VM still doing silly things with tunnels?

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I am able to get almost 500 Mbit/s over my tunnel (typically 420-460) but my IPv4 connection now reaches almost the mythical 1 Gbit (sometimes even a tad over). I suspect this isn't VM now (though of course they might still be a factor) but rather something else. The 'problem' with VM used to be that their routers were very bad at handling the IPv4 UDP traffic that 6in4 tunnels rely on but I have observed that with my new Hitron Chita router I can now run iperf3 IPv4 UDP tests and achieve around 800 Mbit/s (the test server is the limiting factor for me in this case).

IPv6 intrinsically has more overhead, plus the HE tunnel MTU is also 1480 versus the normal 1500 so both those will add some extra overhead (though not 60% of course). I have also observed that many IPv6 routes seem to have a path MTU of only 1280, for some inexplicable reason, so that will certainly impact throughput too.

Much as I'd love to blame VM I think they are probably off the hook in this case. I think the reduced IPv6 throughput compared to IPv4 is likely due to a combination of factors rather than one single thing. But that's just a guess really.

[lewislfoster]

Not sure if anyone else has mentioned this but ive noticed im receiving ICMP6 router advertisements on my WAN interface and it does appear to give prefix information, i am yet to try to configure my router (pfsense, got a hub 4 in modem mode) for dual stack WAN, currently using hurricane electric's 6in4 tunnel for IPv6 connectivity (so far i havent noticed any performance issues with it). Ill try configuring my router to use prefixes from the router advertisement and see how it works (if at all)

[adhawkins]

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@lewislfoster wrote:

Not sure if anyone else has mentioned this but ive noticed im receiving ICMP6 router advertisements on my WAN interface and it does appear to give prefix information, i am yet to try to configure my router (pfsense, got a hub 4 in modem mode) for dual stack WAN, currently using hurricane electric's 6in4 tunnel for IPv6 connectivity (so far i havent noticed any performance issues with it). Ill try configuring my router to use prefixes from the router advertisement and see how it works (if at all)

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I think this has been mentioned before, although not sure prefixes were also being advertised.

Be interested to hear how you get on.

Andy