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Background:

This question has been raised here and marked as duplicate. However, it is not fully addressed.

To reproduce (not exactly):

  1. Set your DNS to 180.76.76.76 (the Baidu DNS http://dudns.baidu.com/)
  2. Stay out of China and DON'T use any proxy
  3. Visit or http://www.ikea.com/gb/en/
  4. You should be redirected to Ikea China.
wlnirvana
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1 Answers1

4

The IKEA DNS server is returning a different answer based on which DNS server asked the question. If you set your DNS server to the baidu, baidu asks the IKEA server from its IP, and then returns the answer to you.

In essence, the answer depends on who asks the question. Then it's just a simple matter for that IP to redirect you to Ikea China.

Example:

Use the DNS server you mentioned in China:

$ dig @180.76.76.76 www.ikea.com

; <<>> DiG 9.8.1-P1 <<>> @180.76.76.76 www.ikea.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42974
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 10, ADDITIONAL: 0

;; QUESTION SECTION:
;www.ikea.com.          IN  A

;; ANSWER SECTION:
www.ikea.com.       3600    IN  CNAME   www2.ikea.com.edgesuite.net.
www2.ikea.com.edgesuite.net. 17565 IN   CNAME   www2.ikea.com.edgesuite.net.globalredir.akadns.net.
www2.ikea.com.edgesuite.net.globalredir.akadns.net. 3600 IN CNAME a1686.co.w.tl88.net.
a1686.co.w.tl88.net.    20  IN  A   210.192.114.198
a1686.co.w.tl88.net.    20  IN  A   210.192.114.146

Use my default DNS server in the US:

$ dig www.ikea.com

; <<>> DiG 9.8.1-P1 <<>> www.ikea.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 7945
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.ikea.com.          IN  A

;; ANSWER SECTION:
www.ikea.com.       292 IN  CNAME   www2.ikea.com.edgesuite.net.
www2.ikea.com.edgesuite.net. 21525 IN   CNAME   www2.ikea.com.edgesuite.net.globalredir.akadns.net.
www2.ikea.com.edgesuite.net.globalredir.akadns.net. 3600 IN CNAME a1686.q.akamai.net.
a1686.q.akamai.net. 20  IN  A   70.96.0.112
a1686.q.akamai.net. 20  IN  A   70.96.0.106
schroeder
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Steve Sether
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  • Do you think adding reference to DNS geolocation concept in answer would help others look for additional details about the concept? – jhash Sep 29 '15 at 21:13