IPv6 support
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David Glover (1562) 8 posts |
I have no idea how feasible this is, or whether it’s been suggested before (a quick search turned up nothing particularly relevant) but my ISP (Comcast US) has deigned to award us with native IPv6 at home, and suddenly all my network devices are happily chatting to each other using it, except for my RISC OS Pi. This is obviously is not a particularly high priority right now, there is very little on the internet that is IPv6-only, but it won’t stay that way forever and eventually v6 support will become required. |
Sprow (202) 1153 posts |
It’s on the roadmap already, and would probably make sense to tie up with Wifi support, although that might make the task too big to swallow in one bounty. Most operating systems seem to be taking a dual stack approach, where IPv6 and IPv4 coexist. A new Internet module would likely be required, along with new ports of all the command line tools that live in !Internet, an updated Socket library (Socket Lib 6 presumably?), extra options in !InetSetup, revisiting any other modules that might have made assumptions about the size of addresses, I recall that DHCPv6 is quite different to normal DHCP, and all the ethernet drivers would need work (for example where they filter by multicast address family), which probably suggests the DCI4 spec would need updating too, possibly a softloadable set for older machines (if stuff like Freeway changed protocol). All do-able, but it’s quite a long road. |
Chris Evans (457) 1614 posts |
I understand why IPv6 is necessary for WAN. AIUI Many/most routers that are IPv6 capable to the outside world can be used with a IPv4 internal LAN. What advantages are there to a user to have a IPv6 LAN? (Assuming they are not opening up there network for access from the outside) |
Steve Pampling (1551) 8154 posts |
bq.AIUI Many/most routers that are IPv6 capable to the outside world can be used with a IPv4 internal LAN. IPv4 – IPv6 gateway essentially
Apart from being able to use a globally unique address, not a great deal. Downside is the extra overheads in IPv6 traffic. Take a switch not designed for the IPv6 handling and add a few (3-5) W7 machines in default (IPv6 and multicast turned on) measure the CPU utilisation on the switch. Turn off the IPv6 and multicast and repeat the measurement. I’ve got graphs showing 15-20% reduction in CPU activity with IPv6 off.
Ah, now there’s the rub. Keeping IPv4 closed down is awkward enough. |
Theo Markettos (89) 919 posts |
So you can talk to IPv6-only hosts on the internet? Otherwise how does your IPv4 packet specify which host to talk to? You can do tunnelling things over an IPv4 only LAN (or WAN), but you still need an IPv6 stack on the endpoints. If you have a non-internet-connected LAN, some of the autoconfiguration mechanisms can be useful – eg simpler than DHCP. IPv4 exhaustion is a problem hitting me at the moment – I’m running a number of very small footprint (eg 64MB) virtual servers. The cost of the IPv4 address is almost more significant than the cost of the server. Meanwhile IPv6 addresses are plentiful.
The UK is a bit of a laggard, but IPv6 adoption in other countries is progressing. According to Google’s stats, 17% of Belgium’s traffic is IPv6, for example. Amusingly, Pace hired me to work on an IPv6 stack in 2001. And then promptly shut the Internet Appliances division and fired me before I even started… |
Rick Murray (539) 13805 posts |
Meanwhile, in France: I have the Microsoft XP IPv6 stack enabled here. So…
[source: http://test-ipv6.com/; needs JavaScript] It seems as if Orange might start rolling out IPv6 some time in 2015. Maybe. If they can get their act together… Given that they haven’t sorted out wonky SSL certificates on their own site in years, I don’t really hold out much hope. Still, I’m quite happy to hide everything behind a NAT. The idea of devices within the house having their own publicly addressable IP does not sit well with me. |
Dave Higton (1515) 3496 posts |
I saw this article on Thursday. The move to IPv6 is seriously starting to happen. If what BT and the BBC say is true, it suggests to me that, by the end of 2016, we may see a large number – maybe even the majority – of consumers having IPv6 addresses. Presumably a large number of web sites will similarly resolve to IPv6 addresses. Once the majority of endpoints is IPv6, I presume it won’t be all that long before almost all are IPv6. And once they are, it’s anybody’s guess how long IPv4 will be supported. After all, why would anybody? We are all aware that the prevalent OSs are Linux (for embedded stuff) and Windows (for non-embedded stuff), and both have supported IPv6 for years. (It’s dubious how many old embedded appliances, like NAS, will continue in service, not supporting IPv6, of course.) So I suspect that IPv6 support is getting urgent now. We have to consider the total time taken, to work out what to do, to do it, to debug it, and to get all RISC OS users updated. It will be no use starting when the rest of the world has already made the transition. |
Steve Fryatt (216) 2103 posts |
Conversely, The Register (who I’d tend to trust a little more to get the technical details correct) suggested last week that NAT-protected networks would probably remain IPv4 for the foreseeable future because there’s little point switching to IPv6. |
Dave Higton (1515) 3496 posts |
How is a RISC OS browser or FTP client going to resolve and connect to an external IPv6 site? |
Chris Mahoney (1684) 2165 posts |
Here in NZ, the local registry (APNIC) was exhausted1 back in April 2011. More than four years later, Google’s stats show that IPv6 adoption is still below 1%. When questioned, ISPs typically say that they have sufficient IPv4 addresses and that while there is no IPv6-only content, there is no incentive to roll out IPv6. It wouldn’t surprise me if other ISPs throughout the world also hold off IPv6 for similar reasons. It probably won’t become commonplace for a while yet… 1 “Exhausted” in this case means “down to the last /8” (which is about 16.7 million addresses). They’re still trickled out when required but you need to justify the request, etc. |
Rick Murray (539) 13805 posts |
Easy. There is a huge amount of IPv4 only stuff running behind a NAT which doesn’t stand a hope in hell of ever being updated. Just because the equipment was obsolete long ago doesn’t mean that it’ll be discarded and people will go and buy new stuff; especially for something as “esoteric” as IPv4 vs IPv6 which I can’t imagine the average guy really understanding.
Ha. Haha. HAHAHAHA. Orange was going to roll out IPv6 for 2014. I think the target date now is 2017 possibly-maybe and given that the Livebox firmware was <expletive> for about a year and is forced on us muppets (the box upgrades itself, we have no say in the matter), I really really would prefer them to not use their client base as unappreciated beta testers again.
Just as a matter of note, Facebook is IPv6 internally. Sorting out and managing IPv4 addresses within Facebook got to be a nightmare, so the whole system was changed to run exclusively IPv6. You talk to it via your browsers and phones (the huge majority of which are IPv4) via a gateway that translates. It can be done. It would be ridiculous to arbitrarily “break the Internet” by making a switch that renders a lot of things instantly incompatible.
Hasn’t it been “urgent” for years?
I agree that RISC OS needs to be forward looking enough to have IPv6 on the timetable, but don’t think the world is one day going to switch over. There are sociopolitical issues with IPv6, as well as the obvious technical ones. I suspect that it might be easier in the short term to try to claw back some of the IPv4 addresses that were handed out like confetti in the early days. |
Steve Pampling (1551) 8154 posts |
The 30Mb on 100Mb bearer line I put in during 2013 has a set of IPv4 addresses and IPv6. It isn’t new. It is particularly urgent either.
And lots of reasons in those NAT protected networks to remain IPv4. Unless you have lots of processor power of course. If you have multiple IPv6 enabled devices on your network right now, check the CPU use on the switches and the devices then turn of the IPv6 use and check the stats again. So I suspect that IPv6 support is getting urgent now. Hasn’t RISC OS needed a decent IPv4 stack for years? |
Dave Higton (1515) 3496 posts |
How is a RISC OS browser or FTP client going to resolve and connect to an external IPv6 site? |
Ralph Barrett (1603) 153 posts |
Via a router that supports IPv6 Network Address Translation. Much in the same way that NAT works for IPv4 at present ?? Ralph |
Dave Higton (1515) 3496 posts |
With IPv4, when a name resolution request goes out, an IPv4 address comes back. With IPv6, when a name resolution request goes out, an IPv6 address comes back. No RISC OS software that I know of can connect to an IPv6 address. So I take it that you’re suggesting that the router intercepts the returned name resolution packets and substitutes an IPv4 address of its own invention? Once the connection has been made, I have no trouble understanding NAT between IPv6 and IPv4 at IP level. I just question how much protocol-level translation we are going to require and rely on in the router. |
Rick Murray (539) 13805 posts |
Yes, I think the router does it. It’ll be an outlay though as I doubt a 200MHz MIPS clone like in today’s hardware will hack it. The things can barely manage two clients with one of them streaming off a USB stick… It gets worse. |
Dave Higton (1515) 3496 posts |
Forgive me, but why is this in any way different from what many of us have with IPv4 today? When I was with Pipex/Talktalk, I had the same IP address for years. (That’s about the only good thing I can say about Talktalk, but that’s another story…) Since I’ve had BT Infinity, despite my keeping the router on 24/365, my IP address changes every few weeks at the longest. For the one service I rely on accessing from outside the house, I use a free DNS provider. Strictly there’s a second – WD My Cloud – but their proprietary protocol takes care of that. |
Rick Murray (539) 13805 posts |
Did you read the article? With dynamic IP, your outward IP address changes, but your Pi at 192.168.1.10 and the PC at 192.168.1.12 and the router and this and that and….will all remain the same. The article implies that if dynamic IP is used with IPv6, then it could be that all these things will change as they will have world assigned addresses and not be behind a NAT. Big. |
Rick Murray (539) 13805 posts |
BTW – my IP address changes all the time with Orange. Luckily the Livebox has DynDNS and NoIP support built in, so I have a “ddns.net” address automatically updated by the router; and the world can find me there, with the router forwarding data to the other side of the NAT. Port 80 to my Livebox is responded to by the Pi. |
Steve Pampling (1551) 8154 posts |
As I said earlier the work is done on the IPv6 leaf device. If the end device is a PC running dual stack (or even plain single stack IPv6) it does the donkey work along with the leaf device at the other end, meanwhile the ISP’s routers just chuck the data in the right direction. As I also said earlier you can disable IPv6 on a dual stack machine and observe the difference in performance. NAT-PT on the router obviates the need for a individual user device to have IPv6 support, but as Rick has pointed out current cheap CPU routers are likely to struggle. |
Rick Murray (539) 13805 posts |
I understood the question to be asking how does an IPv4 device talk to an IPv6 network. In this case, it’ll surely need to be the router as the leaf device wit know how… |
Steve Pampling (1551) 8154 posts |
Perhaps I should have expanded and said they would struggle even if someone modified the firmware to give them the capability. ISP’s could of course configure their kit to run that IPv4 to IPv6 translation outbound from the user to the net, but it’s cheaper to leave the user with the bill for the processor power to drive that conversion. BT will have IPv4 /IPv6 conversion in place as they run the N3 network and that customer isn’t easy to ignore. |
David Feugey (2125) 2709 posts |
IPv4 / IPv6 is really transparent for all DSL modems today. Here, I have access to Internet in IPv6 (Free.fr) with a box that manages an IPv4 internal network. Not a big deal. Not even a deal :) |
Steve Pampling (1551) 8154 posts |
If only. 1 I did the configuration on the “business hub” supplied by BT just a couple of weeks ago. That was a business hub 3 – even the v4 version is a subject of debate about being able to be upgraded to IPv6 capability or not. |
Dave Higton (1515) 3496 posts |
Of course. It wasn’t clear, even on re-reading, that he tacitly assumes that there will be no NAT between LAN and WAN. If that’s the case, then one consequence is that your ISP will have to assign you not just one IP address, but a block of them, in order to make multiple devices externally accessible. |
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