geo dns resolving flapping geo-dns results

[m...@medianetworkservices.com]

Hi! 

We have a customer which uses 8.8.8.8 and 8.8.4.4 as their DNS servers in a datacenter on the US East and West coast.

They also use a geo dns provider (seems to be dnsmadeeasy.com).

One thing we noticed on the DNS SRV records being looked up via the google DNS on the west coast is that

on around 15% of the requests (tested with 2 runs of 1000 requests, the result was always 15%) returned the European 

and not the US host. If looked up from the US West coast 100% returned the correct US entries.

A traceroute to 8.8.8.8 looks ok and does not change over time, also the source ip is the same and it can also 

be reproduced from an other ip address range in the same data center. 

Any comment on what this might cause or even address it?

My guess is that the google dns are load balanced and that the result comes from a different internal DNS server 

which somehow is handled different or the remote DNS server changes the result based on the real ip of the google dns 

server request and identifies that wrong.

I tried the Google DNS flush just to see if it makes a difference, but it did not. Also then 1000 requests and 15% wrong.