Why macbook connects to IPV6 destination instead of IPv4 for web server
Hi Community,
I have a problem while accessing website URL https://www.billdesk.com from Macbook system.
Site works fine without www in URL like https://billdesk.com
As per below dig command output it seems billdesk.com site has a IPV6 IP address 2001:e48:22:2::4
; <<>> DiG 9 <<>> @localhost www.billdesk.com ANY ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4425 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;www.billdesk.com. IN ANY ;; ANSWER SECTION:
www.billdesk.com. 38387 IN A 210.210.24.66
www.billdesk.com. 13798 IN AAAA 2001:e48:22:2::4
;; Query time: 0 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;;
WHEN: Tue Apr 26 08:22:13 2016 ;; MSG SIZE rcvd: 78
When I connect to https://billdesk.com then connection goes for 210.210.24.66 port 443
MacBook-Air:~ user1$ netstat -n | grep 443
tcp4 0 576 10.0.0.10.56630 210.210.24.66.443 ESTABLISHED
tcp4 0 576 10.0.0.10.56629 210.210.24.66.443 ESTABLISHED
tcp4 0 0 10.0.0.10.56628 210.210.24.66.443 ESTABLISHED
tcp4 0 576 10.0.0.10.56627 210.210.24.66.443 ESTABLISHED
tcp4 0 429 10.0.0.10.56624 210.210.24.66.443 ESTABLISHED
tcp4 1460 0 10.0.0.10.56623 210.210.24.66.443 ESTABLISHED
MacBook-Air:~ user1$ netstat -n | grep 443
tcp6 0 0 2601:646:8e01:83.56693 2001:e48:22:2::4.443 FIN_WAIT_1
tcp6 0 0 2601:646:8e01:83.56692 2001:e48:22:2::4.443 FIN_WAIT_1
tcp6 0 0 2601:646:8e01:83.56633 2001:e48:22:2::4.443 FIN_WAIT_1
tcp6 0 0 2601:646:8e01:83.56632 2001:e48:22:2::4.443 FIN_WAIT_1
tcp6 0 0 2601:646:8e01:83.56448 2001:e48:22:2::4.443 FIN_WAIT_1
MacBook-Air:~ user1$
Please let me know why Macbook is making connection to IPV6 address when www is in URL?
Thanks,
Ram
iPhone 6 Plus, iOS 9.3, Its common with all the OS versions