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Why IPv6 is so complicated

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Re: Why IPv6 is so complicated

#141

Post by estimator7292 »

eqvinox wrote: post #45
rusk wrote: post #38

Earlier quoted context omitted.

Wait til you’ve got to copy & paste em, or see em comingled with hw addresses

Wait till you find an application that accepts 1.65793 as an IPv4 address. Or 134744072. $ ping -c 1 1.65793 PING 1.65793 (1.1.1.1) 56(84) bytes of data. 64 bytes from 1.1.1.1: icmp_seq=1 ttl=54 time=1.56 ms --- 1.65793 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 1.560/1.560/1.560/0.000 ms (by the way, this was way less of a dumb peculiarity back when IPv6 wa…

I damn near have a stroke every time I try to reason about IPv4 addresses as an integer. But hey, I guess four bytes is four bytes no matter how you read them.

Re: Why IPv6 is so complicated

#142

Post by seba_dos1 »

gucci-on-fleek wrote: post #82
j16sdiz wrote: post #71

Earlier quoted context omitted.

ULA give more trouble than what it solves. Almost all computer have multiple interface (virtual or not). Application now need to know which interface the destination is on, and there is no easy data structure to store the interface

> ULA give more trouble than what it solves. How? They're essentially the same as IPv4 addresses; the only difference is that there are way more of them, so address conflicts are much less likely. > Almost all computer have multiple interface (virtual or not) Sure, but that's the case with IPv4 too: my cell phone has one IPv4 address over WiFi and another over cellular, and my laptop has one IPv4 address over WiFi an…

> LLAs (...) and don't have an IPv4 analog

They do. You don't really see them on Linux unless configured manually, but Windows defaults (or at least defaulted in the past, my Windows-foo is very outdated by now) to a IPv4 LLA when DHCP fails.

The difference is that IPv6 requires it on every interface regardless of whether it has a different address already.

Re: Why IPv6 is so complicated

#143

Post by Hikikomori »

ExoticPearTree wrote: post #133
Hikikomori wrote: post #109

Earlier quoted context omitted.

>In the enterprise space, if you mention globally reachable address space, the discussion tends to end pretty fast because “its not secure”. Those people love their NAT. Was also designed in the early 90s before security was taken seriously.

> Was also designed in the early 90s before security was taken seriously. True, but since then it has transformed into “no one gets in because we have _private_ IP addresses”…

To be fair it's a pretty decent defense, in the early days of blaster and today with iot crap.

Re: Why IPv6 is so complicated

#144

Post by XorNot »

9dev wrote: post #124
XorNot wrote: post #117

Earlier quoted context omitted.

I don't care to remember them, but I do want them to be consistent so there's no dependency in DNS. My home network isn't the Internet and isn't large: DNS is a much more complicated system to keep running then just fixed IP addresses in that circumstance. Above a certain scale, that flips but not at the home level.

At the home level, you have a home router that can do mDNS out of the box. All devices are reachable by their hostname.

A router which can be switched off sometimes, or break and delay replacement.

I don't want all my IoT devices going down because they can't resolve hostnames - that's why I set fixed IP addresses for them. It means how they communicate with each other and my network is well-defined, and works provided they have Layer 2 (easy to keep up - it works provided any 1 AP is online, whereas my internet or the router providing it can vanish).

Re: Why IPv6 is so complicated

#145

Post by hnlmorg »

9dev wrote: post #135
ExoticPearTree wrote: post #132

Earlier quoted context omitted.

> Are we not? Because I suppose most people here are only disgruntled by a new protocol that changes how their home router works, and having to spend some learning effort. People at home don’t care about protocols. If the WiFi works and the TV plays Netflix or Hulu or whatever, the protocol can be anything. Last time I “cared” was when I changed the DHCP network to not overlap with the VPN. And that was a long time a…

That would be my take as well, but feel free to read some of the sibling comments here, eager to bikeshed over the IPs of their equipment.

HN users aren’t typical home users.

Also I’m really not seeing many people here “bikeshedding” over their home gear. Are you sure you’re reading these comments and not some other IPv6 discussion? Because those conversations definitely do happen but this particular thread hasn’t gone like that.

Re: Why IPv6 is so complicated

#146

Post by icedchai »

wongabu wrote: post #128
icedchai wrote: post #126

Earlier quoted context omitted.

The actual solution is network prefix translation. You effectively NAT the primary network when failed over to the secondary. See https://docs.netgate.com/pfsense/en/latest/recipes/multiwan-... for an example.

That's one ugly hack, which assumes (1) WAN1 has static ipv6 (the typical SME has dynamic DHCPv6 address...) (2) all the devices will behave correctly when running on NPT on failover WAN2. Many devices do not know about NPT which is basically NAT for ipv6, and break on p2p protocols like voice, video, streaming. They'll send the wrong NPT address to the other side, which try to connect back to the WAN1 address, which…

It is a hack, no argument. It seems fine for web traffic... You'd have to do some scripting to handle the dynamic prefixes. My own dynamic v6 prefix hasn't changed in years.

If you want "real" failover, get an ASN, your own prefixes, and run BGP. I know that's not for everyone!

Re: Why IPv6 is so complicated

#147

Post by orev »

threiw wrote: post #46
bryden_cruz wrote: post #28

I recently had to set up basic IP-based country detection in Nginx for a project. Parsing and handling IPv4 is trivial. The second I had to account for IPv6 string formats and update the Geo databases to match, the complexity just spiked for no good reason. It feels like we traded address exhaustion for parsing nightmares.

On one of my linux machines the "localhost:8080" did not work after new installation. It resolves to local ipv6 address, while server only listened on ipv4. After this I go out of my way to disable, remove and nuke ipv6, out of every setup and deployment I do. Ipv6 is already quite complicated, but supporting TWO competing network stacks, with complicated pseudo compatibility, just multiplies unnecessary complexity!

What you seem to be misunderstanding is that your whole process of nuking IPv6 is more work than studying the issue for a few minutes and then listening on both protocols. Setting a service to listen on a port will use both IPv4 and IPv6 by default, and if yours isn’t means you’re probably already doing something wrong or also have other bugs.

Re: Why IPv6 is so complicated

#148

Post by b112 »

AndrewDucker wrote: post #33
b112 wrote: post #22

Earlier quoted context omitted.

Far easier to use ipv8, which just has 5 octets instead of 4.

That still means replacing every part of the chain.

There are lots of legacy things in tcp/ip headers. One of them can be for the extra octlet.

When ipv4 legacy flies around, that oclet will be null or 0. The entire internet could route just fine, especially if you put the extra octlet at the end. 1.1.1.1 gets an extra 1.1.1.1.newoctlet.

So every existing IP gets a bonus 255 new IPs, and for now, routing of those is hardlocked to that IP, and it works with all legacy gear.

In 30 years or something, we can care about the mobility of those new IPs.

Re: Why IPv6 is so complicated

#149

Post by Dagger2 »

eviks wrote: post #36

This is not very substantive, but rather procedural, like this example of an answer doesn't tell you much, but tells you the official paper IDs: > Actually, we tried that: the "IPv4-Compatible IPv6 address" format was defined in {{RFC3513}} but deprecated by {{RFC4291}} because it turned out to be of no practical use for coexistence or transition. Why/how did it turn out?

Try it and see!

  192.168.1.1$ ip link set sit0 up
  192.168.1.2$ ip link set sit0 up
  192.168.1.2$ ping ::192.168.1.1
  64 bytes from ::192.168.1.1: icmp_seq=1 ttl=64 time=0.812 ms
(It works over the Internet too, though make sure your firewall doesn't block protocol 41 and that the packet doesn't get NATed.)

Notice how this doesn't really help you at all. You still need a functional v4 network, you still need v6 support in the kernel on both sides and your programs still need to support AF_INET6 sockets -- at which point, why not just use ::ffff:192.168.1.1 which sends packets without the tunnelling and doesn't need OS support on the far side, or 192.168.1.1 which works with AF_INET sockets and doesn't need tunnelling or any OS support on either side? This is strictly worse than the former option and less compatible than the second.

Re: Why IPv6 is so complicated

#150

Post by Dagger2 »

commandersaki wrote: post #136
muppetman wrote: post #11

This annoys me, especially the last “It takes at least 25 years” rhetoric. It didn’t take 25 years for SSL. SSH. Gzip encoding on HTTP pages. QUIC. Web to replace NNTP. GPRS/HSDPA/3G/4G/5G They all rolled out just fine and were pretty backwards and forwards compatible with each other. The whole SLAAC/DHCPv6/RA thing is a total clusterfuck. I’m sure there’s many reasons that’s the case but my god. What does your ISP s…

Yeah the at least 25 years thing is a cop out. The IPng committee specifically chose the protocol that didn't have a transition plan, and today still doesn't have a transition plan. I expect we're going to plateau with adoption for a long while now. 50% adoption is meaningless if it doesn't tangibly make a dent in the IPv4 exhaustion problem.

Well, other than the transition plans that it has and still has. The exact same plans that the other options like TUBA had.

If you ignore those then sure, it didn't have a plan.

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