A Reddit post from user Accendil on the r/theydidthemath community.

Posted on December 31, 2014
https://redd.it/2qxgxw

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

I've been a lover of IP addressing for many years, since I was in high school. I always found it funny how IPv4 had so few addresses because of the unexpected take off of the "internet".

I then started looking in to IPv6 and this was my first foray into mega numbers which lead me down a slippery slope of Googolplexes and Infinity but IPv6 is my first love. Here is some info related to IP addressing (heavily rounded for ease of viewing):


IPv4 = 2^32
4,290,000,000
| | | Hundreds
| | Thousands
| Millions
Billions

IPv6 = 2^128
340,000,000,000,000,000,000,000,000,000,000,000,000
| | | | | | | | | | | | Hundreds
| | | | | | | | | | | Thousands
| | | | | | | | | | Millions
| | | | | | | | | Billions
| | | | | | | | Trillions
| | | | | | | Quadrillions
| | | | | | Quintillions
| | | | | Sextillion
| | | | Septillions
| | | Octillion
| | Nonillion
| Decillion
Undecillion


Comparison to humans:

1.1. Estimated population of Earth (~2014)
7,210,000,000

1.2. Average number of molecules in an average human body
156,000,000,000,000

1.3. Average number of atoms in an average human body 5,940,000,000,000,000,000,000,000,000

1.4. Estimated number of atoms in the current human race 42,800,000,000,000,000,000,000,000,000,000,000,000


Comparison to things:

2.1. All the grains of sand on Earth
7,500,000,000,000,000,000

2.2. All the stars in the universe
70,000,000,000,000,000,000,000

2.3. Diameter of the observable universe (in millimetres!!) 92,000,000,000,000,000,000,000,000,000


Side-by-side comparison to humans:

v6 340,000,000,000,000,000,000,000,000,000,000,000,000
1.1 7,210,000,000
1.2 156,000,000,000,000
1.3 5,940,000,000,000,000,000,000,000,000
1.4 42,800,000,000,000,000,000,000,000,000,000,000,000
| | | |
| Octillions | Billions
Undecillions Trillions

This means we can give about 7 IPv6 addresses to each atom in the entire human race! Or, you could give each person Earth right now this many IPv6 addresses:

47,261,439,850,130,342,147,690,917,698
|
Octillion


Side-by-side comparison to things:

v6 340,000,000,000,000,000,000,000,000,000,000,000,000
2.1 | 7,500,000,000,000,000,000
2.2 | 70,000,000,000,000,000,000,000
2.3 | 92,000,000,000,000,000,000,000,000,000
| | | |
Undecillions| | Quintillions
| Sextillions
Octillions

You could therefore give each grain of sand this many IPv6 addresses:

45,300,000,000,000,000,000
|
Quintillion

Or even more magnificently, this means you can give every millimetre from one side of the universe to the opposite side of the universe in a straight line about 3.6 billion IPv6 addresses... every... millimetre...

...aaaand now my head hurts so I'll leave it there.


u/accendil on r/theydidthemath
https://redd.it/2qxgxw

... No. of IPv6 Addresses: 340,000,000,000,000,000,000,000,000,000,000,000,000

--- Mystic BBS v1.12 A49 2024/05/29 (Linux/64)
* Origin: Northern Realms (618:400/23)

Warpslide wrote to All <=-

I've been a lover of IP addressing for many years, since I was in high school. I always found it funny how IPv4 had so few addresses because
of the unexpected take off of the "internet".

The US government still owns about 30% of the IPv4 block. However, with
NAT, that's not an issue. IPv6 has a very slow adoption rate in the US
because of NAT and the high cost of switching to IPv6-enabled commercial equipment.

My own ISP uses IPv6 externally, but internally, it's all IPv4.

Trying to manually subnet a IPv6 address is damn near impossible.

-- Sean

... My other computer...hey, where IS my other computer?
--- MultiMail/Linux
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Warpslide wrote to All <=-

A Reddit post from user Accendil on the r/theydidthemath community.

Posted on December 31, 2014
https://redd.it/2qxgxw

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= -=-=-

I've been a lover of IP addressing for many years, since I was in high school. I always found it funny how IPv4 had so few addresses because
of the unexpected take off of the "internet".

Interesting post - thanks for sharing. IPv6 feels very old-school, the intention was to put everything on the internet and to make everything
directly accessible. This was long before the botnet era - imagine if
every device on your LAN had an external IP?

I wonder if the proliferation of NAT as a way of working around IPV4
address exhaustion has helped make us a network of content consumers, not participants in a greater experiment.

One thing I'd alway heard about IPV4 is that part of the problem was the inequality of IP space allocation. Doesn't GE have an entire class A? I
know some earlier companies have entire class Bs, like BBN?





--- MultiMail/Win v0.52
* Origin: realitycheckBBS.org -- information is power. (618:300/16)

Re: Re: Just how big is IPv6?
By: digimaus to Warpslide on Mon Dec 23 2024 05:00 pm

Howdy,

Trying to manually subnet a IPv6 address is damn near impossible.

What do you mean?

I use /112's and /88's a lot...


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

Re: Re: Just how big is IPv6?
By: Kurt Weiske to Warpslide on Mon Dec 23 2024 03:22 pm

Howdy,

Interesting post - thanks for sharing. IPv6 feels very old-school, the intention was to put everything on the internet and to make everything directly accessible. This was long before the botnet era - imagine if
every device on your LAN had an external IP?

Well the design of IP6 is that everything does have an external IP, and the role of the router changes from being a NAT router/firewall, to just a router/firewall.

I'm looking forward to the day we can turn of IP4 - and I know it probably will be a long time before we get there - but maintaining 2 addresses technologies is a pain.


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

Hello Kurt!

23 Dec 24 15:22, you wrote to Warpslide:

I wonder if the proliferation of NAT as a way of working around IPV4 address exhaustion has helped make us a network of content consumers,
not participants in a greater experiment.

That is why NAT was developed and why IPv6 adoption has been so slow for the last 20+ years.

One thing I'd alway heard about IPV4 is that part of the problem was
the inequality of IP space allocation. Doesn't GE have an entire class
A? I know some earlier companies have entire class Bs, like BBN?

The feds own over 30% of the IPv4 Class A blocks.

-- Sean


... "A handful of good life is better than a bushel of learning." - George Herbert
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Hello Deon!

24 Dec 24 14:09, you wrote to digimaus:

I use /112's and /88's a lot...

Good for you. It's difficult for me.

-- Sean

... What orators lack in depth they make up in length.
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Deon George wrote to Kurt Weiske <=-

I'm looking forward to the day we can turn of IP4 - and I know it
probably will be a long time before we get there - but maintaining 2 addresses technologies is a pain.

Especially when the Internet Service Providers (excuse me, online
content providers) can do workarounds cheaper that preserve "their" idea
of us as content consumers instead of nodes participating in an
internetwork.

In 20 years, we could either see widespread adoption of IPv6 and a new generation of network, or ISPs throwing carrier grade NAT everywhere,
locking down the ability of consumers to self-publish content
and self-host (Because, "Liabilities") and charging a premium for the
same IPV4 address that they used to "give away" for free.

Enshittify the internet then charge extra for the solution, that seems
to be a pattern.



--- MultiMail/Win v0.52
* Origin: realitycheckBBS.org -- information is power. (618:300/16)

digimaus wrote to Warpslide <=-

My own ISP uses IPv6 externally, but internally, it's all IPv4.

If I set up IPv6 on my WAN interface, I get an IPv6 address, but never
figured out what to do with it - and when I run IPv6 tests, it complains
my ISP isn't fully configured for it.

Whenever I get an IPv6 address, I get a netmail from one of the Fido
guys about configuring my BBS for it - I guess they look for fido nodes
with IPv6 addresses for a list they keep?



--- MultiMail/Win v0.52
* Origin: realitycheckBBS.org -- information is power. (618:300/16)

Re: Re: Just how big is IPv6?
By: Kurt Weiske to digimaus on Tue Dec 24 2024 10:41 am

Howdy,

If I set up IPv6 on my WAN interface, I get an IPv6 address, but never figured out what to do with it - and when I run IPv6 tests, it complains
my ISP isn't fully configured for it.

I agree with Sean's sentiment, that configuring IP6 can be confusing, because firstly its differnent to IP4, and secondly because to use it you need to configure your side of the router to use it (instead of using what the router uses for IP4 which is normally a 192.168... address from the factory - ie: turn on a use).

Fortunately, many PCs and servers automatically start to use it - its the router part that can be complicated.

Happy to try and help you use it if you want, but might not be worth the effort, if any internet site you visit is not IP6 enabled. Many here in Oz arent, and until they are, there really isnt any reason to change.


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

On 24 Dec 24 10:41:38, Kurt Weiske said the following to Digimaus:

If I set up IPv6 on my WAN interface, I get an IPv6 address, but never figured out what to do with it - and when I run IPv6 tests, it complains
my ISP isn't fully configured for it.

IPV6 is incredibly overrated... and in my case, unnecessary for a long time to come as my ISP has no plans with it.

Nick

--- Renegade vY2Ka2
* Origin: Joey, do you like movies about gladiators? (618:500/24)

Hello Kurt!

24 Dec 24 10:41, you wrote to Deon George:

In 20 years, we could either see widespread adoption of IPv6 and a new generation of network, or ISPs throwing carrier grade NAT everywhere, locking down the ability of consumers to self-publish content
and self-host (Because, "Liabilities") and charging a premium for the
same IPV4 address that they used to "give away" for free.

My ISP gives me a public facing "static" IPv4 address for $5 a month. They charge $5 to pay for the extra Juniper router they bought to do this.

Very few people request this feature from what their tech support tells me. Only those of us who run a server of any kind. Evidently Minecraft servers are very popular.

"Static" being a very long TTL on a DHCP address.

-- Sean

... "All progress springs from me." - Anonymous
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Hello Kurt!

24 Dec 24 10:41, you wrote to digimaus:

digimaus wrote to Warpslide <=-

If I set up IPv6 on my WAN interface, I get an IPv6 address, but never figured out what to do with it - and when I run IPv6 tests, it
complains my ISP isn't fully configured for it.

pfSense will tell me it fails to get an IPv6 DHCP IP from my ISP. Only IPv4.

Whenever I get an IPv6 address, I get a netmail from one of the Fido
guys about configuring my BBS for it - I guess they look for fido
nodes with IPv6 addresses for a list they keep?

No clue. Talk to Andrew; he is our resident IPv6 fanatic. He's running an IPv6<->IPv4 tunnel.

-- Sean

... Clones are people two.
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Hello Nick!

24 Dec 24 17:02, you wrote to Kurt Weiske:

IPV6 is incredibly overrated... and in my case, unnecessary for a long time to come as my ISP has no plans with it.

With IPv4 NAT, a lot of the big ISPs here in the US are lathe to change. I can't speak for anywhere else though.

-- Sean

... "I cannot live without books." - Thomas Jefferson
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

On 24 Dec 2024, Deon George said the following...

I use /112's and /88's a lot...

I've been playing around with subnetting IPv6 here, my ISP gives me one /64 by default (18,446,744,073,709,551,616 or 18.4 quintillion usable host addresses).

I also discovered if I set my wan interface to request a /48 they'll give me one of those as well. A /48 has 65,536 /64 subnets.

I initially tried setting my config to request a /62 (4 /64s) and /61 (8 /64s) but it didn't seem to work, not sure if its my EdgeRouter 4 or my ISP that doesn't support them but a /48 works fine.

This is when I started doing some reading on just how many addresses are available in IPv6. I was initially concerned about hoarding
1,208,925,819,614,629,174,706,176 (1.2 septillion) addresses, and for some reason still am, probably just "old" thinking. 1.2 septillion addresses is a mere 0.0000000000000036% of the total IPv6 address space. Numbers this big really boggle (my|the) mind.

I have 4 vlans here at home, each of them has their own /64 (with 65,532 other /64s just waiting to be allocated).

I could try slicing up one /64 into 4 /66s or something, not sure if my router supports that, but could be a fun exercise to try and see what happens. I suppose I really don't need to be concerned with hoarding/wasting such a "small" number of addresses.


Jay

... Some of the crowd have decided to voice their opinion by staying away

--- Mystic BBS v1.12 A49 2024/05/29 (Linux/64)
* Origin: Northern Realms (618:400/23)

Re: Re: Just how big is IPv6?
By: Warpslide to Deon George on Wed Dec 25 2024 09:24 am

Howdy,

I initially tried setting my config to request a /62 (4 /64s) and /61 (8 /64s) but it didn't seem to work, not sure if its my EdgeRouter 4 or my ISP that doesn't support them but a /48 works fine.

Yeah, I havent got to work out how the backend works - but I see a similar result.

My ISP gives me a /60, and I've played around requesting a /63, /62, and I still get the /60.

I could try slicing up one /64 into 4 /66s or something, not sure if my router supports that, but could be a fun exercise to try and see what happens. I suppose I really don't need to be concerned with hoarding/wasting such a "small" number of addresses.

For the most, and on a VLAN, you'd probably want to stick to a /64 - it'll makes auto configuration easy - and just works. IE: Plug in device, select IP6 and magically it gets one and routing.

Anything less than a /64, you'll need to manage the gateway and routing yourself.

In my case, I play with docker - and containers can have their own IP6 address on their own virtual network. Which is where I use /112s - still gives each docker network 65,535 addresses, and you generally would only use a few on each network :) And since a docker host can potentially have many networks, inside it, I route the /88 to the docker host - manually configured on my router. In reality, I could reduce this to a /96 or even smaller.

The first thing to help, is your gateway address is a link-local fe80::/10, not the first (or last) address in the subnet (which we traditionally do with ip4), and you get that from the device you are routing to after its IP6 stack is running. Generally you dont need to configure the routing back, because it will get that from SLAAC (/64 setup).

happens. I suppose I really don't need to be concerned with hoarding/wasting such a "small" number of addresses.

One of the things I'm liking, and it might just be a conincidence, I see many less bot probs on IP6. The address space is just too big for somebody to probe each one :)


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

Re: Re: Just how big is IPv6?
By: Kurt Weiske to Warpslide on Mon Dec 23 2024 03:22 pm

Interesting post - thanks for sharing. IPv6 feels very old-school, the intention was to put everything on the internet and to make everything directly accessible. This was long before the botnet era - imagine if
every device on your LAN had an external IP?

I tend to think IPv6 is a clear example of modern overdesigned engineering that takes power from end users and puts it in the hand of the comitee that designed the thing.

IPv6 is fine and dandy until you try to break your home LAN into Internet routable subnets without doing any patchwork. In theory it is easy to do. In practice, it fails because it requires so many more moving parts to be put together than IPv4 and also requires collaboration from your ISP.

This is: if your ISP does not give you proper prefix delegation - which most don't seem to do - you are not going to create proper subnets at layer 3. Period. I guess their idea is you create a layer 2 network for each subnet you need and buy extra prefixes from the ISP.

Seriously, whoever designed this can choke on my cock.

Devices having an external IP is not *too* bad as long as you have proper firewalling in place, but to be honest, once you set an inbound firewall you are killing the selling point of IPv6, which was to offer universally reachable endpoints everywhere. The main issue with a real IPv6 per device is all the tracking that ISP and websites can do, but with the privacy extensions supported by the protocol it does not get worse than current tracking on IPv4.


--
gopher://gopher.richardfalken.com/1/richardfalken
--- SBBSecho 3.23-Linux
* Origin: Palantir * palantirbbs.ddns.net * Pensacola, FL * (618:250/24)

Re: Just how big is IPv6?
By: Sean Dennis to Nick Andre on Wed Dec 25 2024 01:20 am

With IPv4 NAT, a lot of the big ISPs here in the US are lathe to change. I can't speak for anywhere else though.

Here in Spain they are rolling something called DS-Lite. As an aproximation, you can think of it like a plan in which you have a Carrier Grade NAT area that gets tunneled over IPv6 on the ISP end.

You end up having IPv4 access through and endpoint set by the ISP and IPv6 from a "conventional" IPv6 network.

Small providers are skipping the whole thing and staying with IPv4 because there is virtually no demand among consumers. At the clinic we have a business plan with a static IPv4. It is worth mentioning consumer-grade plans from this ISP include IPv6 but professional plans are IPv4 only.


--
gopher://gopher.richardfalken.com/1/richardfalken
--- SBBSecho 3.23-Linux
* Origin: Palantir * palantirbbs.ddns.net * Pensacola, FL * (618:250/24)

Re: Re: Just how big is IPv6?
By: Arelor to Kurt Weiske on Thu Dec 26 2024 11:25 am

Howdy,

I tend to think IPv6 is a clear example of modern overdesigned engineering that takes power from end users and puts it in the hand of the comitee that designed the thing.

Can say I agree with anything in this mail - its certainly not my experience with IP6.

I actually like it, I think it provides more benefits than IP4 - but the only hurdle is that both are still in play.

I look forward to the day that we only have 1 address scheme. I actually dont mind if it is IP4 or IP6 - cant imagine it will be anytime soon though.

I can use both to my advantage. I think they should have bit the bullet and given companies a short period of time to switch over. The first company to make a citizen friendly router would be a market leader.




...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

Here in Spain they are rolling something called DS-Lite. As an aproximation,

^^^^^^^^^^^^^^^^^^^^^

Nintendo already did that. ;)

ISP include IPv6 but professional plans are IPv4 only.

I don't see the need for the jump to IPv6 ....

--- Renegade vY2Ka2
* Origin: Joey, do you like movies about gladiators? (618:500/24)

On 26 Dec 24 19:36, T.J. Mcmillen said the following to Arelor:

I don't see the need for the jump to IPv6 ....

Me neither. If my ISP ever forced me to do so, so be it. My router is ready.

But "until then" things are perfectly fine here with IPV4.

Nick

--- Renegade vY2Ka2
* Origin: Joey, do you like movies about gladiators? (618:500/24)

Hi Nick,
In a message to T.J. Mcmillen you wrote:

I don't see the need for the jump to IPv6 ....

Me neither. If my ISP ever forced me to do so, so be it. My router is ready.

I know when I was with Fido (before they shut down) I got an ipv6 address
but since I switched to bell I don't think I do. Or at least it's a hybrid fake one of some sort.

As I only run "servers" for internal use I'm really indifferent to it all.

But "until then" things are perfectly fine here with IPV4.

Agreed.

Shawn

... Anyone can get old. All you have to do is live long enough.


--- Grumble
* Origin: Dirty Ole' Town (618:618/12)

Hello Deon!

27 Dec 24 08:03, you wrote to Arelor:

Can say I agree with anything in this mail - its certainly not my experience with IP6.

In my 35+ years in IT, you are one of a tiny handful of people who like IPv6. In my professional experience in the US dealing with large corporations like John Deere, they are fully IPv4 internally and externally. No one that I know of is using IPv6 unless they absolutelty have to...except for Andrew Leary. He's a big IPv6 fan.

Ruight now, IPv6 is a solution looking for a problem to solve.

However, like Nick, my network can be easily flipped over to IPv6. I just have to set the IPv6 knob in pfSense to on and it will tunnel external IPv6 to IPv4 intetrnally on my LAN.

-- Sean

... You can observe a lot just by watching.
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Re: Re: Just how big is IPv6?
By: Deon George to Arelor on Fri Dec 27 2024 08:03 am

I actually like it, I think it provides more benefits than IP4 - but the only hurdle is that both are still in play.

If only IPv6 were available, it would be a nightmare. So much IPv6 stuff is half-baked at best.

Take SLAAC as an example. It only works on a narrow set of scenarios and can't convey all the information traditional DHCP does. On a regular IPv4 network where you want hosts to acquire a gateway, ntp server and dns server upon boot, you use DHCP to provide them all with it. SLAAC only gets the basics right (IP, gateway and dns) but if you are serious you are back to DHCP. For even more fun, SLAAC only works within its narrow scenario IF it operates on a network segment of EXACTLY a harcoded size.

Then there is the fact my current home deployment is pretty much non-replicable on IPv6 at all unless the ISP wants to cooperate. Hint: ISP usually don't. Long story short, I have multiple local address spaces (think 192.168.1.0/24 for IoT, 192.168.2.0/24 for my father's junk, 192.168.3.0/24 for surveillance apliances... you get the idea).

If you want to break an IPv6 LAN into segments such as the above you are supposed to pick the prefix provided to you by your ISP and then use DHCP-PD (aka prefix delegation) to break your network into smaller prefixes and assign each to each segment. This would be good and fancy if it worked, but

a) your ISP needs support proper prefix delegation, and so many just don't.
b) it sucks that you need cooperation from an external entity in order to properly administrate your internal network.

And yes, I am aware I could use local addressing, but that removes the advertising point of having everything in ipv6 be Internet routable by default.

This gets so bad I have seen very nasty patchwork done in order to properly separate IPv6 segments, such as NAT66 (wtf?!).


--
gopher://gopher.richardfalken.com/1/richardfalken
--- SBBSecho 3.23-Linux
* Origin: Palantir * palantirbbs.ddns.net * Pensacola, FL * (618:250/24)

Hello Arelor!

02 Jan 25 06:34, you wrote to Deon George:

This gets so bad I have seen very nasty patchwork done in order to properly separate IPv6 segments, such as NAT66 (wtf?!).

I know that when I worked at the local John Deere factory, the entire factory was on a 10.0.0.0/8 on the LAN. I'd be horrified to be forced to redo all of that as IPv6. That entire factory's public traffic went through a single IP address. We did have an internal employee BYOD WiFi VLAN that went through that block also that had its own seperate public IP address.

Sadly, I've forgotten most of what I knew since it's been eight years since I last had to work with that setup.

-- Sean

... Alan's Motto: it's easier to make true enemies than true friends.
--- GoldED+/LNX 1.1.5-b20240209
* Origin: Outpost BBS * Johnson City, TN (618:618/1)

Re: Re: Just how big is IPv6?
By: Arelor to Deon George on Thu Jan 02 2025 06:34 am

Howdy,

Take SLAAC as an example. It only works on a narrow set of scenarios and can't convey all the information traditional DHCP does. On a regular IPv4 network where you want hosts to acquire a gateway, ntp server and dns server upon boot, you use DHCP to provide them all with it. SLAAC only gets the basics right (IP, gateway and dns) but if you are serious you are back to DHCP. For even more fun, SLAAC only works within its narrow scenario IF it operates on a network segment of EXACTLY a harcoded size.

Other than ntp, what else do you need from DHCP? Most (modern?) OS's these days have NTP setup by default - so supplying clients with NTP details is often no longer required.

If you wanted to limit the outgoing connections to an NTP server, to use your NTP server, (and/or DNS server), then you can use NAT rules on your gateway for that. (That's what I do anyway.)

I thought SLAAC worked pretty well - I work for a large company (many 1000's employees), and the IT team turned on IP6 and nobody noticed - in fact I dont recall any announcement about it. I only noticed when I started seeing connections (from work) to my home server over IP6.

Then there is the fact my current home deployment is pretty much non-replicable on IPv6 at all unless the ISP wants to cooperate. Hint: ISP usually don't. Long story short, I have multiple local address spaces (think

If you want to break an IPv6 LAN into segments such as the above you are supposed to pick the prefix provided to you by your ISP and then use DHCP-PD (aka prefix delegation) to break your network into smaller prefixes and assign each to each segment. This would be good and fancy if it worked, but

Hmm... its worked for me, but then my setup my not be as complicated as yours? I get an /60 from my current ISP (my previous one gave me a /56) - and my router dished it out as /64's to each lan interface as it needed to. At one point, I dished out a /62 to a downstream router, and it split it up to /64s for it's lan interfaces.

I've since turned all that off, as when I changed ISPs, my prefix changed and I wanted to flatten my network a bit anyway.

I know not all ISPs here are providing IP6 to clients, but that's normally one of the things I look for when changing. Even my mobile phone uses IP6 over IP4 from my mobile provider.


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

Re: Re: Just how big is IPv6?
By: Deon George to Arelor on Fri Jan 03 2025 03:24 pm

Other than ntp, what else do you need from DHCP? Most (modern?) OS's these days have NTP setup by default - so supplying clients with NTP details is often no longer required.

If you wanted to limit the outgoing connections to an NTP server, to use your NTP server, (and/or DNS server), then you can use NAT rules on your gateway for that. (That's what I do anyway.)

NTP is just the most common assignment that you'd expect the network to provide but SLAAC lacks. There are cetainly other tasks that you'd use DHCP for and that SLAAC is not fitted to service. As far as I know you can't convey PXE information using SLAAC only, for example.

I know you can MITM, hijack, tamper and twist your client's traffic in order to ensure they use your designated DNS and NTP servers. My networks usually have rules for such effect. That said, those things are a last resort. The proper way to get a client configured is to use the protocols designed for configuring clients (weird, I know). Spoofings and internal masquerading and such are there just for when clients suck and I usually set it so a warning is triggered when such mechanisms need apply.


--
gopher://gopher.richardfalken.com/1/richardfalken
--- SBBSecho 3.23-Linux
* Origin: Palantir * palantirbbs.ddns.net * Pensacola, FL * (618:250/24)

Re: Re: Just how big is IPv6?
By: Deon George to Arelor on Fri Jan 03 2025 03:24 pm

Hmm... its worked for me, but then my setup my not be as complicated as yours? I get an /60 from my current ISP (my previous one gave me a /56) - and my router dished it out as /64's to each lan interface as it needed to. At one point, I dished out a /62 to a downstream router, and it split it up to /64s for it's lan interfaces.

That is how it is supposed to work, that is how I have never seen it work in the wild.

To me, it is like UEFI key management. It is great when it works but I rarely see anybody get it right. So far I know no ISP in my country that does not give you the bare minimum /64 assignation and then can't deal with PD.

And, to me, that is a big part of the point: if you depend on your ISP's DHCPv6 to properly configure your LAN the whole thing is a bit brittle. Firewall specifications for IPv6 filtering require a whole lot of traffic to be allowed from and to your ISP because changes in the ISP state have repercussions in the state of your LAN. What happens if the ISP's DHCP service goes down? Chances are your router keeps operating with the last lease set it got, but that leaves your LAN in an inconsistent state. Meanwhile an IPv4 LAN can operate pretty much forever in a consistent state if the whole Internet suddenly disappears.


--
gopher://gopher.richardfalken.com/1/richardfalken
--- SBBSecho 3.23-Linux
* Origin: Palantir * palantirbbs.ddns.net * Pensacola, FL * (618:250/24)

Re: Re: Just how big is IPv6?
By: Arelor to Deon George on Sat Jan 04 2025 09:29 am

Howdy,

NTP is just the most common assignment that you'd expect the network to provide but SLAAC lacks. There are cetainly other tasks that you'd use DHCP for and that SLAAC is not fitted to service. As far as I know you can't convey PXE information using SLAAC only, for example.

I dont think SLAAC was ever considered/planned to be a replacement for DHCP. Sure there is overlap (assigning addresses, routes) - and its enough if you dont need the other stuff.

Spoofings and internal masquerading and
such are there just for when clients suck and I usually set it so a warning is triggered when such mechanisms need apply.

Or when you have users who want to bypass the lan setup - especially to get access to something the lan setup was trying to deny.


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)

Re: Re: Just how big is IPv6?
By: Arelor to Deon George on Sat Jan 04 2025 09:40 am

Howdy,

And, to me, that is a big part of the point: if you depend on your ISP's DHCPv6 to properly configure your LAN the whole thing is a bit brittle.

I dont think that is a fair comparison.

I have both a IP4 net and and IP6 net - which if I was concerned things would break when the ISP messes up, goes down or something else, then I define those nets and routing on my side (which I do). My link can go offline (and sometimes does), and my IP6 network is fine, as is my IP4 net. This is how it was done on the IP4 setup (which the assigned net wasnt provided by an upstream DHCP server), and can still be done with IP6.

If I dont need/care about the addresses, then I can leave the router to give me something and let it change at will as defined by the upstream configuration (which in this case is the ISP). Ala dynamic ip6, which I know some ISPs provide to clients.

Anyway, I dont think anybody dependant on systems being "available" regardless of the status of an internet link, to leave the network config to an unknown 3rd party. You should expect problems if that was the case.


...oEoN
--- SBBSecho 3.23-Linux
* Origin: I'm playing with ANSI+videotex - wanna play too? (618:510/2)