[Starlink] Info on IP country ranges

Tue Dec 12 05:33:14 EST 2023

Hi Alex,

Thank you for the further detail, my apologies if I misunderstand your line of inquiry. I had interpreted it to mean that you were still not convinced it was native from the perspective of the end-user visible components.

You are right that there may be some IPv6-in-IPv4 encapsulation occurring within the Starlink network that is undetectable to end-users. That said I would be surprised if that was the case but as you highlight can't say conclusively, not having inside knowledge as to their architecture.

If it helps, the latency and throughput I have measured of IPv4 vs IPv6 on Starlink is comparable, so if encapsulation is occurring it doesn't appear to be having a noticeable performance impact.

Regards,
Steven

On Tue, 12 Dec 2023, at 9:22 PM, Alexandre Petrescu wrote:
> Le 12/12/2023 à 03:43, Steven a écrit :
>> Thanks for this reference that explicitly states it is IPv6 native.
>>
>> https://support.starlink.com/?topic=1192f3ef-2a17-31d9-261a-a59d215629f4 is another Starlink resource that confirms that a /56 is provided. This one doesn't explicitly mention native, but as mentioned I am confident it is.
>
> Thanks for the pointer.  It clarifies indeed almost all my questions 
> about IPv6 to starlink end users.  It is clear about that /56 to end 
> users.  You also provided confirmation that is with DHCPv6-PD, and not 
> tunnelbroker nor 6to4.  This is already very good.
>
> What I further asked (is IPv6 encapsulated in IPv4?) might probably not 
> be within the reach of non-starlink administrators, not visible to 
> starlink end users.  Sorry for having given the impression that I might 
> doubt the skilfullness.
>
> For example, in 3GPP networks, it is also said, and generally agreed by 
> very skilled persons, that almost all IPv6 is provided as native IPv6. 
> In that context, it means that the packets from smartphone to a core 
> network entity are not encapsulated in IPv4. But, it is also agreed that 
> within that core network, that IPv6 is encapsulated in the GTP protocol, 
> which is an UDP/IPv4 protocol. This encapsulation of IPv6 in IPv4 is 
> invisible to end users, even if the encapsulation is there.
>
> For 3GPP, the use of GTP is very much dedicated to supporting mobility - 
> a user keeps a same IP address while changing base stations and S-GWs or 
> SGSNs.  In starlink, on the contrary, it is probably not the case that 
> the GTP protocol is used for mobility (I dont know?), because starlink 
> says that the IP address might change during mobility (that URL you 
> point to says "Our system is dynamic where moving the Starlink to 
> another location [...] may cause the public IP to change."); so maybe 
> IPv6 is not encapped in UDPv4.  Still, another role of GTP in 3GPP is 
> that of providing a notion of 'circuit', for needs such as AAA: one such 
> 'circuit' is associated to one authenticated and billed user.  And 
> starlink users _are_ authenticated and billed, too.  Thus, one might 
> wonder what other than 3GPP's GTP protocol is starlink using to provide 
> that notion of 'circuit'-per-user.  Maybe that starlink-circuit protocol 
> is using tunnels, and that tunnel might be an IPv4 tunnel; it might also 
> be an IPv6 tunnel.  Maybe it is using MPLS. Maybe something else.
>
> It is  worth considering about standards work, interoperability with 
> others, a probable NTN-TN convergence, and similar.
>
> Alex
>
>>
>> Cheers,
>> Steven
>>
>> On Tue, 12 Dec 2023, at 1:29 PM, J Pan wrote:
>>> yes. https://starlink-enterprise-guide.readme.io/docs/ip-addresses
>>> "Starlink is IPv6 native network. Using IPv6 is more flexible and
>>> future-proof." starlink has greatly improved tech docs
>>> --
>>> J Pan, UVic CSc, ECS566, 250-472-5796 (NO VM), Pan at UVic.CA, Web.UVic.CA/~pan
>>>
>>> On Mon, Dec 11, 2023 at 5:10 PM Steven Honson via Starlink
>>> <starlink at lists.bufferbloat.net> wrote:
>>>> Hi Alex,
>>>>
>>>> As an experienced network engineer with extensive experience with IPv6, I'm confident this is native IPv6.
>>>>
>>>> Cheers,
>>>> Steven
>>>>
>>>> On Tue, 12 Dec 2023, at 2:30 AM, Alexandre Petrescu wrote:
>>>>> Steven,
>>>>>
>>>>> Thanks for the clarifications. It is indeed very advantageous to use
>>>>> DHCPv6-PD from a Client in home to starlink Server, and obtain a /56.
>>>>>
>>>>> But to be native IPv6, it would need the IPv6 packets to travel natively
>>>>> (sit directly on the link layer) between home and starlink network.  If
>>>>> these IPv6 packets are encapsulate in IPv4, then there would be a risk
>>>>> of additional latency compared to v4.
>>>>>
>>>>> A possible way to find out whether it's IPv6 native (and hence no
>>>>> additional latency) is to browse speedtest.net from an IPv4-only client
>>>>> vs from an IPv6-only client.  An IPv6-only Windows client can be made by
>>>>> unchecking the IPv4 box in interface Properties window.
>>>>>
>>>>> Ideally, if it is IPv6 native, the latency reported by speedtest.net is
>>>>> approximatively the same on IPv4 vs on IPv6 (sometimes the IPv6 latency
>>>>> is even lower than on IPv4).  If the latency reported on IPv6 is higher
>>>>> than on IPv4 it could be for many reasons, and one of them could be that
>>>>> IPv6 is not native, but encapsulated in IPv4.  The IPv4 encapsulating
>>>>> endpoint could be on Dishy.
>>>>>
>>>>> Alex
>>>>>
>>>>> Le 08/12/2023 à 13:24, Steven a écrit :
>>>>>> Alexandre,
>>>>>>
>>>>>>> Are you sure the DHCPv6-PD server is in Starlink network and not on the
>>>>>>> MikroTik router?
>>>>>> That would be quite the unusual setup, and even so would require that I obtain said /56 from elsewhere (such as via a tunnel) to then delegate back to myself...
>>>>>>
>>>>>>> It could be that the MikroTik router runs tunnelbroker, obtains a /56
>>>>>>> from HE, splits that /56 into multiple /64s and puts it on the DHCPv6-PD
>>>>>>> local server config files.
>>>>>> I am confident this is not the case since I configured these routers from scratch.
>>>>>>
>>>>>>> It could also be that the DHCPv6-PD server is run on the Dishy.
>>>>>> It is unlikely that it is on the Dishy, as the latency to the DHCPv6 servers IP address, as well as the first IP hop, indicates the usual Ground->Space->Ground latency I'd expect.
>>>>>>
>>>>>>> It could also be that the DHCPv6-PD server is run on the starlink ground
>>>>>>> network: maybe on the teleport, maybe deeper on the starlink network.
>>>>>> Yes, this is the most likely place they are running this, likely the PoP you are being routed through.
>>>>>>
>>>>>>> Do you know the IPv6 address of your DHCPv6-PD Server?
>>>>>> The DHCPv6 server address is a Starlink IPv6 address, the same one as my default gateway (`2406:2d40:xxx:xxx::1`). The /56 I am being allocated is also from the same /32 as this DHCPv6 server, with the /32 being 2406:2d40::/32, which you'll note is allocated to Starlink.
>>>>>>
>>>>>> Cheers,
>>>>>> Steven
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