Subject: Re: [dnsext] Re: a definition of consistency

From: Ondřej Surý <[email-masked]>
Date: Fri, 05 Feb 2010 15:57:42 +0100

On 29.1.2010 16:21, Colm MacCárthaigh wrote:
> 2010/1/29 Jim Reid<[email-masked]>:
>>> I saw your complaints about language choice and redirection, but I'm
>>> not sure how this is related to DNS tricks.
>>
>> Because it's stupid DNS tricks that are responsible for taking my browser to
>> pages in languages I don't understand and didn't ask for.
>
> I really doubt that it is. Do you think it's likely that those page
> providers have distinct network end-node destinations on a
> per-language basis? For a concrete example; When I query
> google.com/nl/ie/co.uk/be/ch and so on, I actually get the same IPv4
> result. I'm being directed to my closest node (probably a data-centre
> in Dublin, where I also live). I presume the IP is the front-end of
> some kind of load-balancer, or the Google web-server. But the language
> negotiation is orthogonal, and likely based a combination of
> Accept-Lang and Host headers, or possibly a GeoIP lookup on the HTTP
> client-ip.
>
> Can you provide one concrete example where incoherent DNS responses
> result in being directed to sites that respond in different languages
> purely based on the ultimate destination IP address?

You just gave one - Google.

http://pastebin.com/m363f6ebb

O.
-- 
  Ondřej Surý
  vedoucí výzkumu/R&D manager
  -------------------------------------------
  CZ.NIC, z.s.p.o.    --    Laboratoře CZ.NIC
  Americka 23, 120 00 Praha 2, Czech Republic
  mailto:[email-masked]    http://nic.cz/
  tel:+420.222745110       fax:+420.222745112
  -------------------------------------------

---

From: Wilmer van der Gaast <[email-masked]>
Date: Fri, 5 Feb 2010 15:27:54 +0000

> http://pastebin.com/m363f6ebb
I don't see how this proves your point.

No matter which Google IP address you connect to, you'll get the same
response to the same HTTP request. The forward you're showing here is
sent to you because your *HTTP* connection comes from a Czech IP
address.

When I don't want to see Dutch content (which is usually the case), I
usually use http://www.google.com/ncr which disables the country
redirect.

Google does *NOT* use DNS to send you content in a different language,
and I hope nobody else does because there are much better ways to do
it.

Wilmer.

-- 
Wilmer van der Gaast, Dublin Traffic SRE.
Google Ireland.

---

From: Nicholas Weaver <[email-masked]>
Date: Fri, 5 Feb 2010 07:27:06 -0800

> http://pastebin.com/m363f6ebb

Actually, I don't believe Google does that.

Rather, what I believe happens is that it does a geoip lookup on the IP address where the actual HTTP request comes from, and does an HTTP redirect to the country-specific version.  This behavior could be validated by passing the request through a non-US tunnel but using the US DNS result.

So its using DNS to direct you to "closest" instance of www.google.com, and that then does the redirect to the country-specific version.

---

From: Ondřej Surý <[email-masked]>
Date: Fri, 05 Feb 2010 16:39:00 +0100

On 5.2.2010 16:27, Wilmer van der Gaast wrote:
> 2010/2/5 Ondřej Surý<[email-masked]>:

True.  I was more thinking about example of website which gives you 
content in strange foreign language regardless of what you really 
requested.  Sorry for not reading Colm's sentense more precisely.  It's 
Friday afternoon after all...

> usually use http://www.google.com/ncr which disables the country

Ah, thanks for hint.

Ondrej

---

From: Nicholas Weaver <[email-masked]>
Date: Fri, 5 Feb 2010 07:47:42 -0800

> Rather, what I believe happens is that it does a geoip lookup on the IP address where the actual HTTP request comes from, and does an HTTP redirect to the country-specific version.  This behavior c…

I can however verify the opposite:  I did a lookup bounced through a new zealand DNS server, the address it gave for www.google.com was:
www.google.com.         380081  IN      CNAME   www.l.google.com.
www.l.google.com.       270     IN      A       66.249.89.103
www.l.google.com.       270     IN      A       66.249.89.147
www.l.google.com.       270     IN      A       66.249.89.99
www.l.google.com.       270     IN      A       66.249.89.104

When I connect to that server directly using Telnet and send a HTTP request, I get back what looks to be the normal google homepage blob, but I know the google standard behavior when you are connected from a foreign country is to do a redirect to the country-specific version.

---

From: "Everhart, Craig" <[email-masked]>
Date: Fri, 5 Feb 2010 12:10:34 -0500

> -----Original Message-----
> From: Ondřej Surý [mailto:[email-masked]]
> Sent: Friday, February 05, 2010 10:39 AM
> To: Wilmer van der Gaast
> Cc: Colm MacCárthaigh; [email-masked]
> Subject: Re: [dnsext] Re: a definition of consistency
> 

Is there some reason that the user should need to know this, though, for each site that tries to be tricky like this?

		Craig