Hi all.
I'm searching for a work arownd that let me use external dns other than mi isp offers, for example google public dns or opendns ones.
My internet connection is a little unusual, I use a cellular phone as modem bluetooth connected to my PC.
My isp has two access point names (apn), one suitable for WAP connection browsing internet directly from cellular display, and an other one suitable for regular connection from PC.
I often use wap apn to connect from my PC, It works, but seems to be few differences and limitations:
- private ip, wap connections are organized as a lan
- seems there is a proxy that rewrites web pages (probably form better view on cellular displays)
- ping utility doesn't work for external ips out of this "wap LAN"
And so on... theese are the most important limitations I noticed.
But there is an other annoing one:
DNS request to external public dns services are disabled... look at the follow example (first try is via google dns, second on opendns, last using my isp dns):
Code:
# dig @8.8.8.8 www.google.com
; <<>> DiG 9.4.2-P2 <<>> @8.8.8.8 www.google.com
; (1 server found)
;; global options: printcmd
;; connection timed out; no servers could be reached
# dig @208.67.222.222 www.google.com
; <<>> DiG 9.4.2-P2 <<>> @208.67.222.222 www.google.com
; (1 server found)
;; global options: printcmd
;; connection timed out; no servers could be reached
# dig @213.230.155.94 www.google.com
; <<>> DiG 9.4.2-P2 <<>> @213.230.155.94 www.google.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 65076
;; flags: qr rd ra; QUERY: 1, ANSWER: 7, AUTHORITY: 4, ADDITIONAL: 4
;; QUESTION SECTION:
;www.google.com. IN A
;; ANSWER SECTION:
www.google.com. 17208 IN CNAME www.l.google.com.
www.l.google.com. 27 IN A 209.85.135.147
www.l.google.com. 27 IN A 209.85.135.99
www.l.google.com. 27 IN A 209.85.135.103
www.l.google.com. 27 IN A 209.85.135.104
www.l.google.com. 27 IN A 209.85.135.105
www.l.google.com. 27 IN A 209.85.135.106
;; AUTHORITY SECTION:
google.com. 12594 IN NS ns2.google.com.
google.com. 12594 IN NS ns4.google.com.
google.com. 12594 IN NS ns3.google.com.
google.com. 12594 IN NS ns1.google.com.
;; ADDITIONAL SECTION:
ns1.google.com. 17032 IN A 216.239.32.10
ns2.google.com. 20177 IN A 216.239.34.10
ns3.google.com. 50283 IN A 216.239.36.10
ns4.google.com. 12949 IN A 216.239.38.10
;; Query time: 808 msec
;; SERVER: 213.230.155.94#53(213.230.155.94)
;; WHEN: Tue Sep 21 09:32:04 2010
;; MSG SIZE rcvd: 284
As you can see it's possible for me to do a dns request to my isp dns server, but i can't query an external dns service.
What's exactly the matter in your opinion?
Seems that they block something related to ICMP, because also if I ping an adress like 209.85.135.147 I don't obtain any response...just time out.
It's strange... I've tried to contact any other private ips (10.x.x.x) of this "lan" and ping works....
Hope my bad english is clear enaugth to let you understand the problem.
I hope you have ideas about this limitations and eventually solutions to bypass it.