[Pdns-users] PowerDNS Recursor / dnsdist: EDNS Client Subnet

[Brian Candler]

On 24/11/2019 10:50, Bjoern Franke via Pdns-users wrote:
> E.g. if I use DoT with my mobile phone and come from 89.15.232.0/21 
> (o2 Germany in Hamburg), usually the traffic to Akamai is routed to 
> Akamai in Hamburg if I use o2's DNS, OpenDNS or 8.8.8.8. Using my 
> dnsdist in Nuremberg, Akamai traffic is routed to Frankfurt.
>
> I enabled "useClientSubnet=true" for dnsdist and several EDNS Client 
> options in PowerDNS Recursor (ecs-add-for, edns-subnet-whitelist, 
> use-incoming-edns-subnet) but nothing changes. 

Have you tried running tcpdump on the traffic:

- between dnsdist and recursor;
- between recursor and authoritative nameservers?

Can you see the client-subnet option in the packets?  At least it will 
tell you which of the two servers is not adding (or forwarding) 
client-subnet.