Four (simple) IPv6 questions

[FreshJR]

1) Is the following nvram variable always set?

ipv6_prefix=

Is it available in the following user configurations:

• IPv6 - native (statefull)
• IPv6 - native (stateless)
• IPv6 - passthrough
• IPv6 - static ?

Will the variable ever include the "::" shortener as part of its value? (Not important to know, just curious)​

2) Will the ISP ever assign multiple IPv6 lan prefixes for subnetting / isolating networks? If yes, do any Asus-WRT routers take advantage of this?

3) If my current IPv6 address space is /64. Is that 64bit range all exclusively for my devices ?

Just making sure since I don't know if my router runs the DHCP server or if the ISP runs the DHCP server for the /64 range.​

4) Is the assigned IPv6 address space ever greater than /64? Aka, is there some crazy ISP that assigns more than 18 QUINTILLION addresses per user?

I ask because I can save nvram space by omitting the prefix half when storing local device rules in nvram

This would allow me to store the last 64bits + CIDR range per local device rule while only being required to store full 128 bits + CIDR range per remote device rule

​

--

I have one more questions concerning:

- the routers assigned WAN ipv6 / 128 address that is not within the LAN /64 range
- devices being assigned (TWO) ipv6 addresses ??!?

But lets get the easy stuff out of the way first, while I google the other questions I have.

 

[Adamm]

Is it available in the following user configurations:

• IPv6 - native (statefull)
• IPv6 - native (stateless)

Will the variable ever include the "::" shortener as part of its value? (Not important to know, just curious)

Yes, yes and yes.

4) Is the assigned IPv6 address space ever greater than /64? Aka, is there some crazy ISP that assigns more than 18,446 QUADRILLION addresses per user?

Yes this is very common, ISP's are supposed to assign a /56 per customer, but each ISP has their own implementation some being more generous then others, so this can end up being a /64 /60 /56 or even /48 IIRC.

 

[FreshJR]

Yes, yes and yes.

Just to clarify:

Are you unsure about the nvram varaible "ipv6_prefix" when using the following two configurations?

IPv6 - passthrough
IPv6 - static

Thanks!!

 

[Adamm]

Are you unsure about "ipv6_prefix" when using the following two configurations?

Yeah not too sure as I have "native" IPv6 and only had a few weeks to play around with it. Better leave it to someone else then give an inaccurate answer

 

[FreshJR]

Yes this is very common, ISP's are supposed to assign a /56 per customer, but each ISP has their own implementation some being more generous then others, so this can end up being a /64 /60 /56 or even /48 IIRC.

You'd think assigning 1.2 septillion addresses per user is .... I dont know .... a little excessive.

How many IOT devices do they think we have. Before you know it we are out of IPv6 addresses ....

 

[sinshiva]

fun little tidbit, that shortener also exists in ipv4. ie. 10.1 = 10.0.0.1 and 1.1 = 1.0.0.1

so you can check out the cloudflare site for their secondary ipv4 dns at https://1.1

 

[Adamm]

You'd think assigning 1.2 septillion addresses per user is .... I dont know .... a little excessive.

How many IOT devices do they think we have. Before you know it we are out of IPv6 addresses ....

I think it comes down to future proofing, a carriers (realistically) almost infinite IPv6 allocation and the fact a /60 only allows 16 subnets for guest networks etc. Much easier to get it right the first time then having to re-implement it a few years down the track (it took my ISP 2 and a half years of planning). There's a good discussion on the topic over at Whirlpool where we successfully convinced my ISP too change their roll-out from a /64 to /56 per user to fit RIPE guidelines and keep enthusiasts happy

 

[FreshJR]

I think it comes down to future proofing, a carriers (realistically) almost infinite IPv6 allocation and the fact a /60 only allows 16 subnets for guest networks etc. Much easier to get it right the first time then having to re-implement it a few years down the track (it took my ISP 2 and a half years of planning). There's a good discussion on the topic over at Whirlpool where we successfully convinced my ISP too change their roll-out from a /64 to /56 per user to fit RIPE guidelines and keep enthusiasts happy

WOW, was not aware that you can't subnet within /64 without breaking IPv6 features /standards.

@Adamm I have a few questions for you since you have 256 subnets alloted by your ISP.

Your IPv6 address takes the following form:

aaaa:aaaa:aaaa:aabb:cccc:cccc:cccc:cccc

a - global routing prefix
b - subnet ID
c - interface ID

1) does your ipv6_prefix variable appear as?

aaaa:aaaa:aaaa:aa

OR​

aaaa:aaaa:aaaa:aabb
​

2) I don't think you can take advantage of the IPv6 subnets via the AsustWRT UI? Is this correct?

If AsusWRT only uses 1 subnet, is bb in your IPv6 addresses always set to 00?​

3) Found my answer.

Stateless doesn't use a DHCP server.
Instead, device on stateless IPv6 networks generate address given the advertised IPv6 prefix.​

 

[Adamm]

1) does your ipv6_prefix variable appear as?

aaaa:aaaa:aaaa:aa

OR
aaaa:aaaa:aaaa:aabb

2) I don't think you can take advantage of the IPv6 subnets via the AsustWRT UI? Is this correct?

Correct as far as I'm aware, can't say I've messed around with Guest networks a whole bunch though.

If AsusWRT only uses 1 subnet, is bb in your IPv6 addresses always set to 00?

Yes as seen above.

 

[heysoundude]

You'd think assigning 1.2 septillion addresses per user is .... I dont know .... a little excessive.

How many IOT devices do they think we have. Before you know it we are out of IPv6 addresses ....

we'll all be dead by the time they run out of ipv6 addys. what worries me is the construction of the matrix.

Off Topic/Tinfoil hat shiny side out:
now imagine if each of those IoT devices have GPS chips in them. (don't get me started on 5G and resolution to the millimeter for location services.) Somebody was joking when they mentioned each of us getting a chip in our heads...now it can easily become reality.

 

[martinr]

we'll all be dead by the time they run out of ipv6 addys. what worries me is the construction of the matrix.

Off Topic/Tinfoil hat shiny side out:
now imagine if each of those IoT devices have GPS chips in them. (don't get me started on 5G and resolution to the millimeter for location services.) Somebody was joking when they mentioned each of us getting a chip in our heads...now it can easily become reality.

Great. Look forwards to it. You’ll be able to find your glasses, the nearest ball-point pen, the pocket knife you put down only 10 minutes ago, and, of course, your keys.

 

[heysoundude]

Great. Look forwards to it. You’ll be able to find your glasses, the nearest ball-point pen, the pocket knife you put down only 10 minutes ago, and, of course, your keys.

But where’d you leave your blasted phone to look all of things up with?? Can you ask the fridge? Or will they start reminding you to take things with you?


Sent from my iPhone using Tapatalk

 

[RMerlin]

But where’d you leave your blasted phone to look all of things up with?? Can you ask the fridge? Or will they start reminding you to take things with you?

I have a smart watch (don't ask, it was a freebie) that can actually ring my phone in case I lost it somewhere around, so...