Hi Stefan, I was on a business trip since Sunday evening and now I can - strangely enough - no longer reproduce the issue :/ The machine was in suspend during that time. I rebooted, plugged in a cable, however, everything works as expected. Nevertheless, I will answer your questions below since I hit the issue in the first place.
* Stefan Sperling wrote: > On Sun, Jun 25, 2017 at 08:34:46PM +0200, Matthias Schmidt wrote: > > Hi, > > > > I installed a recent snapshot from June 23 and noticed that slaacd is > > generating IPv6 addresses with privacy extensions enabled in a high > > rate. I can easily reproduce the bug by just starting slaacd. After > > one second I already see 29 IPv6 addresses: > > > > $ ifconfig trunk0 | grep inet6 | wc -l > > 29 > > Does this number keep growing over time? Or does it just > collect a bunch of addresses when the interface comes up? Initially the number was growing over time. After some minutes I had so many fd00:: addresses that the ifconfig output scrolled for some seconds long. > > inet6 fd00::c8c1:eda0:2f1b:7e99 prefixlen 64 deprecated autoconf > > autoconfprivacy pltime 0 vltime 7044 > > inet6 fd00::b081:7ff1:9740:fb6 prefixlen 64 deprecated autoconf > > autoconfprivacy pltime 0 vltime 7044 > > inet6 fd00::3ceb:3269:d174:c8cd prefixlen 64 deprecated autoconf > > autoconfprivacy pltime 0 vltime 7046 > > inet6 fd00::e875:55ac:6557:2d74 prefixlen 64 deprecated autoconf > > autoconfprivacy pltime 0 vltime 7046 > > All the fd00 addresses are from the fc00::/7 prefix. > See https://en.wikipedia.org/wiki/Unique_local_address > > Not sure what the fritzbox is announcing this prefix for. > The fritzbox might be doing this if it does not have a routable IPv6 > prefix yet, perhaps? A prefix lifetime of zero implies that these addresses > are not used for new connections. They should disappear once vltime hits zero. > > > [...] > > What did you omit here? More addresses? Yes. > Were these all from the fc00::/7 prefix? Yes. > Were there any with pltime > 0? Yes. > Could you record router solicitations and router advertisements with tcpdump > and show us what they contain? Does the fritzbox keep announcing the fd00::/64 > prefix with a non-zero prefix lifetime? > > The kernel SLAAC code probably filtered these addresses out somehow. > My guess (from code inspection) is that, in 6.1-release, the fd00 > addresses were replaced once a "real" global prefix was configured. > But the details are not immediately obvious. It's IPv6, after all :) As said above, I no longer see any fd00:: addresses assigned. Whenever the issue comes back, I'll write another email. Cheers and thanks Matthias
