[Pdns-users] pdns-recursor delegate some queries to another recursor

[Brian Candler]

On 20/05/2019 17:57, Tobi <jahlives at gmx.ch> wrote:
> - BGP routing issues (ex from Provider 1 you can reach target and from
> provider 2 not)

That happens, but very rarely in my experience.  In any case, it's the 
responsibility of the authoritative domain owner to host their domain on 
at least two different ASes (RFC 2182), if they care about people being 
able to resolve it.

> - per SRC limits on the recipient side

An authoritative server with that sort of limit, such as could affect a 
single end-user site, would be completely broken IMO.

If you can replicate this issue, then I think it would be worth drilling 
down further with tests to prove or disprove these theories.  It sounds 
more likely that the problem is local to you, either in your network, or 
with your upstream provider - especially if this affects a wide range of 
domains and not just a specific few.  However, routing issues in your 
part of the world may be different to what I see here (in the UK).