From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Carlson Date: Wed, 26 Jun 2019 12:45:43 +0000 Subject: Re: IPv6 with pppd Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ppp@vger.kernel.org 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