IPv6 Fundamentals: A Straightforward Approach to Understanding IPv6, 2nd Edition

If you watch the graph in smaller time scale you see adoption is higher on weekends than on weekdays. I guess that means consumers using Google and similar from their mobile phones have a high rate of adoption. They did not do it themselves. While the average medium (and why not big) company IT department has not started to do anything and is IPv4 only. Seen in the graph when people work Monday to Friday and especially around Christmas.

So did 64 bit CPU adoption get delayed because addresses are hard to read compared to 32 bit addresses? Maybe not so much...

But the argument might still hold. If 80% of average network admins decide to hate IPv6 because they can no longer remember IP addresses of several machines and subnets by heart that might hinder adoption. Most of them are not daily affected by the fact that the world has run out of IPv4 addresses. And NAT works well enough for most of them, many are even convinced it gives them security.

Has anybody read the book? How would you describe the writing style?

Taken from a previous comment I’ve made re IPv6:

IPv6 is fundamentally not ready for real world use within small/medium businesses and homes IMO. At least not without NAT. Why?

- Can’t just simply put one IPv6 router/firewall behind another. Not all IPv6 routers support DHCP-PD, and even if they did, you could have 2-3-4 levels of routers/firewalls at a business. I’m not making this up- retail/gas/food industries often have a plethora of networks at a location, and the business/franchise owner is not tech literate, or even if they were, the equipment is managed by third party vendors and they don’t want to customise their IP network for each location. It makes for messy deployment and maintenance.

- Can’t just simply open a firewall rule on the main site router to forward say HTTPS to an internal service. Why? Not all ISPs give static IPv6 prefixes, not all PCs/servers/devices support DHCP6 for static leases, and then there’s IPv6 privacy addresses. Yes, you can statically configure (only if ISP is static too!). No, I don’t want to open the port to all devices on the LAN and no I can’t rely on each device to be running their own firewall (let alone a properly configured one!).

- WAN failover / multiple ISPs is hard. You have a fibre primary feed, and a secondary cellular/5G feed. Each has different IPv6 addresses. How do you ensure the right ISP is used at any given point? IPv6 shifts this decision to the client. This makes load balancing and policy based traffic routing (eg VoIP over fibre 1, FTP over fibre 2, etc). Also the cost of using a multi-homed IPv6 subnet & BGP in a SME/retail business is out of the question (plus the cellular ISP wouldn’t support it anyway).

All the above works fine out of the box with IPv4 and NAT. It’s bread and butter easy. At the cost of not having dedicated unique public IPs but these places simply don’t need them.

What IPv6 should have done to ensure a smooth migration is allowed for NAT from the very start. That would have let everyone who needed public IPs get them straight away, and those that didn’t to still migrate anyway with as little drama as possible. But it’s just not the case, NAT has been slowly added but it’s support is far from ubiquitous that IPv4 has.

The only "problem" here that is caused by IPv6 is the SD-WAN / multi-provider scenario. Even that is solvable. There are so many IPv6 addresses that your local router can have a unique routable range that it can hand out to the local network, "masking" the external internet provider addresses in the same way that IPv4 routing does it. That's not NAT, that's just routing. E.g. I have a customer that uses a non-RFC1918 public range internally and they have 5 ISP uplinks. They don't need to renumber their internal range just to fail over to another link.

ALL of the other issues are caused by vendors selling garbage products that have IPv6 as a "checkbox" tick without real support.

The real problem is that network engineers around the world let them get away with it, because they avoid IPv6 because of this perception that it isn't mature.

The protocol is over two decades old! It's been fully supported since Windows 2000! My phone is IPv6. My fibre LAN is IPv6. It just works.

What doesn't work is this attitude where people just like you continue to pay for products that only pay lip service to the future.

I've gone on rants here before about enormous service providers like AWS and Azure providing IPv6 "support" that is an absolute garbage fire. Totally worthless. Useless beyond belief. Literally counterproductive in the case of Azure, where turning on IPv6 anywhere will break unrelated IPv4 functionality!

Nobody ever chimes in to say: "Yes, we agree, this is bad."

Nobody ever says "Microsoft should fix this!"

Nobody has a problem. So now we have situations like the one you just described, where people are still buying routers in 2021 that that can't handle the most basic IPv6 functionality.

IPv4 addresses are now USD $40 each and rising exponentially. I really do hope the COVID case number graphs taught some of you in a visceral sense what the world "exponential" means. Hint: it doesn't mean that it'll cost $60 in a decade. Try $40000, each.

My ISP uses carrier-grade NAT on IPv4, breaking sites all over the place. I had to call them to enable a dedicated IPv4 address. Their annual investor report says that they will run out within a couple of years. Get one now while you can is the message.

Do you have any idea how much code is required for two PCs to communicate directly now, with up to 4 NAT layers as a common scenario? It's a huge library you have to integrate in your code and then you need a cloud service to assist it.

This is madness, and network engineers around the world are perpetuating it.