intermittent SERVFAIL for high visible domains such as *.google.com

[Reindl Harald]

Am 23.01.2018 um 13:25 schrieb Brian J. Murrell:
> Here's a new most interesting data point.
> 
> All of these outages happen right after a DHCP client connect and sends
> a DDNS update to BIND.
> 
> It would be an interesting experiment to isolate the zone that receives
> DDNS updates for the DHCP clients onto a separate server to see if that
> makes this problem go away for the main server, but I don't have
> another machine to run another BIND on and I don't think it's possible
> to run two BINDs on the same machine on different ports and have one
> (on port 53) delegate a zone to another running on some other port

pretty sure it's possible and likely not much different than the 
unbound-sample below which asks a rbldnsd on port 1043 on the same machine

stub-zone:
  name: "zone-name."
  stub-addr: 127.0.0.1 at 1053