Infographic on IPv4 Addresses Running Out
dyn.com
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I still never understood why they couldn't just extend IPv4 by adding another octet, and then making all existing IPv4 addresses 0.{current_address}. This would give us about 1 trillion addresses and would make things dead simple.
The only glitch that we ran into in the last nine years was a (self created) configuration error, where we statically added default gateways on hosts/servers that pointed to the router. Those Router IP addresses had been auto-generated VLAN MAC addresses, which where then concatenated with the IPv6 network /64.
Unfortunately, the Cisco routers we were using, generated those EUI-64 addresses for the vlans based on the order they were created - and, after a power cycle, they were created in the order they appeared in the configuration - and all of a sudden our servers no longer had valid routes.
Lesson learned - don't use static gateways on an IPv6 network, let your routers advertise themselves, and, if for some reason (possibly a bad one), you really, really want a static gateway , make sure you don't rely on the auto-EUI-64 generation ability of your router.
Other than that - the protocol has been an easy drop-in replacement for IPv4.
The "Why" of not just adding 0. to IPv4 - is that IPv6 does much more than just increase address length. First of all, it eliminates CIDR - which is the source of many network misconfigurations. All networks in IPv6 are /64s. Further to that, you get stateless address autoconfiguration - nodes can now determine their own address without having to rely on a stateful registry somewhere. Just concatenate the network+mac address (or random number for the privacy sensitive), and you have a routable IPv6 address.
Broadcast is eliminated - and solicited nodes multicast is a very elegant replacement for services like neighbor discovery (rough equivalent of IPv4 ARP)
I could go on - but, I don't know very many IPv6 network operators who dislike the protocol.
If I have to quibble with infographics like these, is that they obscure the fact that IPv4 was able to have variable length subnet masks, I.E. You could have networks that were 24 bits in length (/24) or 27 bits in length (/27) - depending on your requirements. With IPv6 you don't have that freedom - every network is a /64, so, if you are only going to use two hosts on your network (for a network link) - you are still assigning 2^64 addresses to that link, of which you will only use 2, resulting in a "wasted" 2^64 - 2 hosts.
It's odd the first time you do it, but eventually you just learn to live with the fact you have, for all practical purposes, unlimited address space in IPv6 - so wasting 2^32 times as many IP addresses than you had in ALL of IPv4 on just a single routed link turns out to be no big deal.
Quite refreshing that, no matter how simplified or slightly erroneous the data is, it's just kinda hanging out there.
To summarize: we'll run out of IPv4 addresses, and they don't work interchangeably with IPv6. Oh well.
I like it : )
It took until 1995 to get agreement on what IPv6 would look like - but that's still 18 years ago. Plenty of time for a phased changeover :->
I have 1 public IP address and everything works.
We have an an IPv4 allocation problem, TONS of IPv4 space allocated to companies and not used. What we don't have is IPv4 usage problem, or the need for everything "on the internet" to be publicly addressable.
If we want proper peer-to-peer communications to be possible, we need to avoid, where possible, the need for a routable middle-man to help out.
Also, Asia Pacific has long run out of IPv4 addresses - back in 2011. There are now services starting up over there that are IPv6 only. This will spread over the next few years.
IPv6 is the future. There is no point complaining that we can shuffle around a few addresses here and there to make up a bit of space.
For all instant communication (VoIP, chat, file transfer, setting your thermostat), a man in the middle schema is a hindrance. The communication where you publish, and then somebody reads data need a man in the middle.
If your thermostat does not have a public IP, you must buy it as a service, and it'll never really be your property. One can live with that in a thermostat (but let's not pretend it's a good thing), just think twice before automating more of your home...
That is the very reason many people are nervous about the switch. Right now NAT/PAT give home users reasonable security without the need for a firewall. The obvious solution is just to make cheap firewalls that can route properly, and default to blocking all incoming traffic. However, that brings up the same concern of needing some way to dynamically poke a hole through the firewall. Which brings us to UPnP, and I for one do not trust that at all, but maybe thats my tinfoil hat.
I totally agree that we need to move forward with IPv6 though.
What advantage is IPv6 for most of my devices giving me?
And the advantage is that when you _do_ want to go direct you aren't stuck with being behind NAT on your router and then another NAT at your ISP, and then possibly another NAT level, and then the same in reverse at the other end, so that it's possible at all.
And sure, it might not give _you_ anything you particularly care about. But when you find that you can't do something, because there are several layers of indirection between you and someone else, and now you need to run your own server in order to hook two machines to each other over the internet, then you'll wish IPv6 was available.
Also, let's say you want to connect to your Time Capsule when you are on the go. Wouldn't it be nice to be able to connect to its public static IP address directly (assuming you set your firewall to allow such connections).
Lastly, as the Internet goes IPv6 only, your IPv4 only devices will get cut off. This will happen sooner than you might imagine.
Yes, there are large swatches of unused IPv4 addresses, but the demand for new allocations is much greater. Why cling to an old system just to offset its death by a few months when we can spend the effort on making the new system work better?
Let's start admitting that IPv6 offers no (or little) present day net benefits compared to the benefit of currently connecting to all of IPv4. And let's stop with the NAT booggy man argument. NAT works well, as much as any tech works and isn't perfect. And let's stop pretending that only thing stopping a peer 2 peer utopia is the lack of globally unique address. There many economic forces in play beyond that.
(edit spelling fix)
IPv6 does provide real world benefits, not the least of which is the simplification of allocations and a huge price drop in terms of address assignments.
It needs routers to have native IPv6 support.
The real problem is getting ISPs to provide IPv6 support.