@databeestje:
I'm pretty sure that nobody has touched the snort package to work with IPv6 yet. So that probably means that if you use snort you kill your IPv6.
You would at a minimum require the local interfaces to be setup in snort to prevent it from blocking it's own interfaces.
Well, I added the IPv6/IPv4 addresses of the tunnel endpoints to the whitelist as well as the, and the various "autogenerated IPs" checkboxes on the whitelist page, so I figured that would do the trick, assuming these auto-generated addresses would take care of both IPv4 and IPv6 addresses, maybe not.
Also, some of the interfaces added to snort only have an IPv6 address, like the tunnel interface, so I also assumed that being able to do that would mean that snort understands IPv6. Similar, I'd have assumed that adding the LAN interface which has both IPv4 and IPv6 addresses, would lead snort to "get it" that these are local addresses.
So how does Snort figure out what is a "Home net" and what's an "External net"???
Oh well…
The real issue that tricked me, however, was that snort was indeed running, while the status indicated that it wasn't...
In any case, for now, snort is disabled, and IPv6 is back. It was already back with snort enabled and blocking disabled, but I don't need snort just to fill my log files with triggered rules, so if I can't use it to auto-block unwanted traffic, it's kind of pointless, particularly given its resource use.