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