• So I've seen this for a couple of days now… and it's a unique one.

    I'll turn on my Windows system... desktop, laptop, it doesn't matter. IPv6 RA is Stateless DHCP (since Windows doesn't use RDNSS to get DNS server info). Computer receives the RA, determines a SLAAC IP address with privacy extensions, etc.

    IPv6 works great. Sites load using IPv6 (as determined by the IPvFoo extension to Chrome). I can ping hosts using hostname and an IPv6 address is used. IPv6 test sites pass wonderfully.

    24 hours pass... this is the default valid lifetime of the RA. All of a sudden, sites load using IPv4. Pinging a hostname results in the IPv4 address being pinged. IPv6 is no longer preferred over IPv4. BUT... it DOES still work. If I ping -6 google.com, I get replies. IPv6 test sites show IPv6 works, but that IPv4 is preferred.

    Not sure if this is a Windows issue. None of my other devices - Apple (iOS and OS X) or Android, that I can see/tell - have an issue like this. But this issue only just started happening, and the only thing that's changed is the 2.3 snapshots on my pfSense box. I can reboot the computer and IPv6 works great again… for the next 24 hours.


  • Definitely sounds like a windows issue; which version of windows?

  • I'm thinking it is too now… after leaving a couple of my systems on for a couple of days, it seems like only one is really having IPv6 issues after a while, the others must have been temporary issues before. It's Windows 10 on all. I don't think this is a pfSense issue at this point.