Hi! I have a need to update DNS AAAA records, and potentially pf(4) rules or tables when a public routable IPv6 address of my host changes.
Such a change is expected whenever slaacd receives a change in the advertised IPv6 address prefix(es) from the router(s). Other than regularly polling the interface for its IPv6 addresses and comparing to a previously saved state, is there some way to get notified actively when such a change happens? (I am not a friend of polling as it wastes cpu cycles and on average comes with a delay of half the polling interval. slaacd already knows that a change is happening so why not let it tell my script?) Note that I am not concerned about the temporary IPv6 addresses generated by RFC 8981 privacy settings. Just any addresses using a fixed/static Interface Identifier (IID), either manually configured, EUI-64 or randomly generated. In other words this is about incoming traffic from the Internet to services running on my host, not host initiated outgoing traffic. If changes to temporary addresses also trigger my script, I could live with that but I don’t need this information. >From reading the documentation, scripts configured in hostname.if(5) using the >!<command> syntax do not seem to work for this, as they seem to be triggered >only when /etc/netstart is executed? (This is not documented anywhere I could >find.) Would a IPv6 address prefix change be something the hotplug(4) / hotplugd(8) mechanism would see? Can someone enlighten me please? Thanks! Mike
