* Re: IPv6 with pppd
2019-06-26 11:30 IPv6 with pppd Levente
@ 2019-06-26 12:45 ` James Carlson
2019-06-26 14:43 ` Levente
2019-06-26 15:28 ` Michael Richardson
2 siblings, 0 replies; 4+ messages in thread
From: James Carlson @ 2019-06-26 12:45 UTC (permalink / raw)
To: linux-ppp
On 06/26/19 07:30, Levente wrote:
> Dear maintainer,
>
>
> I am struggling with IPv6 over PPP on Linux. The situation is that I
> have a 3G modem, when I plug it in to the USB on my Debian box,
> everything works as expected, I have IPv6 address from the provider,
> and I am happy. But how?
There may be problems with this trace, possibly indicating 3G-specific
authentication issues, but if your only question is about IPv6, the
answer is very simple. PPP doesn't negotiate global scope addresses in
IPv6. It does link-local only. Global scope addresses come from either
ICMPv6 Router Advertisements, DHCPV6 address assignments, or static
configuration.
> Please note that in the logs, I can't see that global scope address,
> and I don't know how the IPv6CP assigns this address to the interface.
> How is this done?
Some other protocol. IPV6CP is not involved.
> And when I plug the same modem to an OpenWRT box, I don't get the
> global scope address, only the link-local address. Is this some PPP
> specific problem, or there might be some IPv6 autoconfiguration magic
> happening in the background? I don't think so, because that address
> corresponds to a statically allocated address of the provider.
>
> lev@mercury:~$ host 2a00:1110:135:4594:303e:582f:ea95:aa10
> 0.1.a.a.5.9.a.e.f.2.8.5.e.3.0.3.4.9.5.4.5.3.1.0.0.1.1.1.0.0.a.2.ip6.arpa
> domain name pointer
> 2A00111001354594303E582FEA95AA10.mobile.pool.telekom.hu.
>
> Could you help me out what is going on here, and why can't I get a
> global scope address on the OpenWRT? I'm sure it is an OpenWRT issue,
> but need help tracing it.
My guess would be that the OpenWRT box doesn't have IPv6 routing enabled
and isn't doing RAs. That's just a guess. I don't believe the issues
you're having here have anything to do with PPP.
--
James Carlson 42.703N 71.076W <carlsonj@workingcode.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: IPv6 with pppd
2019-06-26 11:30 IPv6 with pppd Levente
2019-06-26 12:45 ` James Carlson
@ 2019-06-26 14:43 ` Levente
2019-06-26 15:28 ` Michael Richardson
2 siblings, 0 replies; 4+ messages in thread
From: Levente @ 2019-06-26 14:43 UTC (permalink / raw)
To: linux-ppp
Yes, you are right. This issue has nothing to do with pppd, it is/was
an OpenWRT misconfiguration. BTW, it works now. Thank you for your
suggestion!
Best regards,
Levente
On Wed, Jun 26, 2019 at 2:45 PM James Carlson <carlsonj@workingcode.com> wrote:
>
> On 06/26/19 07:30, Levente wrote:
> > Dear maintainer,
> >
> >
> > I am struggling with IPv6 over PPP on Linux. The situation is that I
> > have a 3G modem, when I plug it in to the USB on my Debian box,
> > everything works as expected, I have IPv6 address from the provider,
> > and I am happy. But how?
>
> There may be problems with this trace, possibly indicating 3G-specific
> authentication issues, but if your only question is about IPv6, the
> answer is very simple. PPP doesn't negotiate global scope addresses in
> IPv6. It does link-local only. Global scope addresses come from either
> ICMPv6 Router Advertisements, DHCPV6 address assignments, or static
> configuration.
>
> > Please note that in the logs, I can't see that global scope address,
> > and I don't know how the IPv6CP assigns this address to the interface.
> > How is this done?
>
> Some other protocol. IPV6CP is not involved.
>
> > And when I plug the same modem to an OpenWRT box, I don't get the
> > global scope address, only the link-local address. Is this some PPP
> > specific problem, or there might be some IPv6 autoconfiguration magic
> > happening in the background? I don't think so, because that address
> > corresponds to a statically allocated address of the provider.
> >
> > lev@mercury:~$ host 2a00:1110:135:4594:303e:582f:ea95:aa10
> > 0.1.a.a.5.9.a.e.f.2.8.5.e.3.0.3.4.9.5.4.5.3.1.0.0.1.1.1.0.0.a.2.ip6.arpa
> > domain name pointer
> > 2A00111001354594303E582FEA95AA10.mobile.pool.telekom.hu.
> >
> > Could you help me out what is going on here, and why can't I get a
> > global scope address on the OpenWRT? I'm sure it is an OpenWRT issue,
> > but need help tracing it.
>
> My guess would be that the OpenWRT box doesn't have IPv6 routing enabled
> and isn't doing RAs. That's just a guess. I don't believe the issues
> you're having here have anything to do with PPP.
>
> --
> James Carlson 42.703N 71.076W <carlsonj@workingcode.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: IPv6 with pppd
2019-06-26 11:30 IPv6 with pppd Levente
2019-06-26 12:45 ` James Carlson
2019-06-26 14:43 ` Levente
@ 2019-06-26 15:28 ` Michael Richardson
2 siblings, 0 replies; 4+ messages in thread
From: Michael Richardson @ 2019-06-26 15:28 UTC (permalink / raw)
To: linux-ppp
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Levente <leventelist@gmail.com> wrote:
> I am struggling with IPv6 over PPP on Linux. The situation is that I
> have a 3G modem, when I plug it in to the USB on my Debian box,
> everything works as expected, I have IPv6 address from the provider,
> and I am happy. But how?
...
> Please note that in the logs, I can't see that global scope address,
> and I don't know how the IPv6CP assigns this address to the interface.
> How is this done?
IPv6CP does not.
The major difference between IPCP and IPv6CP is that it was realized that in
IPv4, the IPCP people were having to repeat all the DHCPv4 work again in
IPCP, and why not just run DHCP?
So in IPv6CP, *ALL* IPv6CP does it assign the LL address (which are either
made up randomly, or come from an IID/EUI/OUI of a physical interface).
Then, an IPv6 RS/RA occurs, which MAY assign an address (M=0), or MAY
suggest using DHCPv6 (M=1). My experience is that many devices do both,
and one winds up with two addresses.
If DHCPv6-PD also occurs (O=1), then there is actually no reason to even
number the PPP link with a GUA, as one can just use a GUA from an downstream
interface.
In my copious spare time, I hope to write an RFC updating 7084 that provides
a way for the ISP to understand what the CPE device would like, such that the
ISP does not have to deal with all the situations of single-device-with-/64,
single-device-that-may-tether-with-/64, WAN-link-numbered+PD, or
WAN-link-unnumbered+PD. There are scaling efficiencies for the ISP in the size of
it's access network routing table if each customer costs a single TCAM slot
rather than two, sometimes three.
> And when I plug the same modem to an OpenWRT box, I don't get the
> global scope address, only the link-local address. Is this some PPP
> specific problem, or there might be some IPv6 autoconfiguration magic
> happening in the background? I don't think so, because that address
> corresponds to a statically allocated address of the provider.
I assume PPPoE, and modem is DSL or CableModem (not dialup).
What version of OpenWRT? 18.06 just works!
Feel free to unicast me your /etc/config/network
--
] Never tell me the odds! | ipv6 mesh networks [
] Michael Richardson, Sandelman Software Works | IoT architect [
] mcr@sandelman.ca http://www.sandelman.ca/ | ruby on rails [
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^ permalink raw reply [flat|nested] 4+ messages in thread