Enforce EDNS

[Daniel Stirnimann]

> Named doesn't have a switch to force EDNS though I suppose we could
> add one to 9.12.  e.g. server ... { edns force; };

I would find this useful.

> I really don't want to add new automatic work arounds for broken
> servers but it requires people being willing to accepting that
> lookups will fail.  That manual work arounds will now have to
> be done. e.g. "server ... { send-cookie no; };"

I can only speak for the DNS resolvers I'm operating but I would be
willing to accept that. At some point in time, those broken name servers
need to be fixed. If more users start sending complaints to the name
server operator that might help.

Daniel