Subj : A small questionary on ISPs
To   : Michiel van der Vlist
From : Victor Sudakov
Date : Sat Oct 16 2021 18:06:26

Dear Michiel,

16 Oct 21 11:23, you wrote to me:

 VS>> Those of you lucky to have a *native* IPv6 connection from your
 VS>> ISP, could you please share what network topology your ISP
 VS>> offers. E.g.

 VS>> 3. A /64 for the link and a /56 for your devices

 MV> I think #3 comes closest.

Thanks for replying.

 MV> I am not sure about the /64 for the link. The only visible part of the
 MV> link is the IPv6 WAN address of the router. It is outside the /56
 MV> assigned to the user, the link may just use a /128.

Do you see the WAN address of the router in the `traceroute -6` output?

 MV> The modem/router supplied by the ISP assigns one /64 for the LAN and
 MV> another /64 for the guest network. More /64 out  of the /56 can be
 MV> obtained by connecting extra routers.

Very little flexibility IMHO. Can you at least assign a static IPv6 address within the LAN /64?

 MV> For IPv6 one must use the modem/router from the provider. When the
 MV> modem/router from the provider is set in bridge mode, the connection
 MV> becomes IPv4 only.

This looks very similar to what I've heard from a Rostelecom representative. This probably means that the IPv6 is not really "native" and there is some kind of tunnel terminated at the provider-owned CPE.

Victor Sudakov, VAS4-RIPE, VAS47-RIPN
--- GoldED+/BSD 1.1.5-b20170303-b20170303
 * Origin: Ulthar (2:5005/49)

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