4 ms·

You are hitting Virgin's GGC (Google Global Cache) servers, which return a different IP than the Google or GGC servers where your IPv6 tunnel is located. Google

You are hitting Virgin's GGC (Google Global Cache) servers, which return a different IP than the Google or GGC servers where your IPv6 tunnel is located. Google is messing with your DNS, not Virgin Media (and they are doing it to improve your performance).

aaronmdjones 12y ago
I did not know about GGC, and that seems cool (and similar to the Netflix approach of putting content servers inside ISP networks). However, this does not explain why I get an address pointing to my ISP network when I query via OpenDNS, which is definitely outside of my ISP network and is an intermediate recursor (so, from the perspective of the nameservers for google.com, the query is not coming from a Virgin Media address range). EDIT: And from the GGC documentation, it does not seem as if the ISPs are required to serve content from the in-ISP nodes to customers outside the ISP, which is what this would look like.
- virtuallynathan 12y ago
  OpenDNS uses edns-client-subnet, which passes the DNS client IP subnet (/24) with the recursion request. Google still knows you are on Virgin Media from behind OpenDNS. http://www.afasterinternet.com/howitworks.htm http://www.afasterinternet.com/howitworks.htm
  - rahimnathwani 12y ago
    Yup. More info here: https://datatracker.ietf.org/doc/draft-ietf-dnsop-edns-client-subnet/ https://datatracker.ietf.org/doc/draft-ietf-dnsop-edns-clien...
  - deleted 12y ago
    [deleted]
  - aaronmdjones 12y ago
    Now THAT, is amazing - and perfectly explains what's going on. I operate several nameservers of my own for various domains, some owned by me, some not, and I'd not heard of that. I am happy with your answer, thanks!
- mrb 12y ago
  Your command log shows you are not using OpenDNS, but Google's Public DNS (8.8.8.8). Are you confusing the two?
  - AAronForMe 12y ago
    I tried again with OpenDNS at the suggestion of someone else in this thread with the same results - see my other comments.

aaronmdjones 12y ago

I did not know about GGC, and that seems cool (and similar to the Netflix approach of putting content servers inside ISP networks). However, this does not explain why I get an address pointing to my ISP network when I query via OpenDNS, which is definitely outside of my ISP network and is an intermediate recursor (so, from the perspective of the nameservers for google.com, the query is not coming from a Virgin Media address range). EDIT: And from the GGC documentation, it does not seem as if the ISPs are required to serve content from the in-ISP nodes to customers outside the ISP, which is what this would look like.

virtuallynathan 12y ago
OpenDNS uses edns-client-subnet, which passes the DNS client IP subnet (/24) with the recursion request. Google still knows you are on Virgin Media from behind OpenDNS. http://www.afasterinternet.com/howitworks.htm http://www.afasterinternet.com/howitworks.htm
- rahimnathwani 12y ago
  Yup. More info here: https://datatracker.ietf.org/doc/draft-ietf-dnsop-edns-client-subnet/ https://datatracker.ietf.org/doc/draft-ietf-dnsop-edns-clien...
- deleted 12y ago
  [deleted]
- aaronmdjones 12y ago
  Now THAT, is amazing - and perfectly explains what's going on. I operate several nameservers of my own for various domains, some owned by me, some not, and I'd not heard of that. I am happy with your answer, thanks!
mrb 12y ago
Your command log shows you are not using OpenDNS, but Google's Public DNS (8.8.8.8). Are you confusing the two?
- AAronForMe 12y ago
  I tried again with OpenDNS at the suggestion of someone else in this thread with the same results - see my other comments.