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ISP Block Some Web Sites

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by alashhar

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in Libya, there is only one ISP and recently it has blocked some web sites such as youtube due to ??????? reasons. anyway some my friends have found a solution which change ISP DNS IP Address to Google DNS IP Address (8.8.8.8) or OpenDNS (208.67.222.222). it is working fine with them,now they can open youtube and other blocked sites. but for me it is not working.

my internet connection statue:

(1)i have Wimax Internet contract
(2)i have Wimax Huawei Internet Gateway
(3)i do not have static IP Address, ISP provides dynamic IP addresses
configuration

Note:
i have changed IP address configuration in Windows XP to google DNS addresses because there is no option in my Gateway to write manually DNS IP address, i have to write all IP addresses Configuration, which cause the Internet stop working.

anybody can give me logic reason ????

22 replies

by ron k.

You confused me pretty good. Care to try again?

by alashhar

after change ISP DNS ip to google DNS addresses, the blocked web sites successfully accessed to my friends, but for me it is not working

by ron k.

Do you mean NOT working?
Once again I'm confused. You didn't answer my other questions either.

by mohammad oweis

Forget about changing DNS address.
Use Google and search for some Proxy avoidance sites and use these sites to connect you to any blocked site.

Changing the DNS from windows will not work, because its point to your gateway.
It should be changed from your gateway.

By the way, how is the quality of the WiMax connection in Libya, i heard that it was awful in the beginning.

by seanferd

"Forget about changing DNS address."

This does work in some cases, until the government accounts for it, too.

"Changing the DNS from windows will not work, because its point to your gateway."

No, not unless you leave the gateway address in the DNS list. You can break local name resolution by doing this, in fact.

If the router, however, can force some or all types of DNS requests (UDP or TCP, port 53 or 5353) to a particular provider, this will limit or block the effectiveness of changing DNS addresses.

The ISP can still force DNS as well if all these bases are covered.

As well as proxy avoidance, using a proxy yourself may or may not work. Some proxies are blocked as well, so trying different ones may help.

Proceed at your own risk. Don't get in trouble with the government.

by mohammad oweis

After a second thought i think you maybe right about changing DNS, because when you change the DNS and use another one like Google DNS, it will be harder for your ISP to spy on you, and you could avoid there blocking mechanism (not always; because they can use traffic inspection boxes like Packeteer and block it, unless if you use SSL)

About splitting DNS requests, i have never thought that an ADSL router could have a feature like this.
This is cool :)

by alashhar

i would like to explain that the problem is from my Wimax gateway device!
the ISP has provided different wimax gateway devices during last year, in all previous gateway devices do not force their users to use the ISP DNS servers, so their users change the DNS addresses in their windows the result they can access to all blocked web sites without any problem.

To Seanferd
"No, not unless you leave the gateway address in the DNS list. You can break local name resolution by doing this, in fact"
in my wimax gateway or router there is no option to just write DNS address only, it enforces me to write IP address + Subnetmask + Gateway address+ DNS address.

by seanferd

I think the second answer was also edited to include "not".

I don't think it would matter how early in the day it is for you. ;)

by seanferd

My only concern with using OpenDNS in some areas of the world is server location in the case of visiting domains which make use of CDNs.

I'm not sure what the routing would be like from Libya, but requests from there should be routed to London or Amsterdam DNS servers. (Of course, you get really weird routing in the U.S. sometimes, from some ISPs and other ASes more than others.)

But CDNs deliver content based on location of the DNS server, not the user's location, so sometimes delivery from CDNs gets laggy or times out. (Better than no delivery ever, I suppose.) Australians using OpenDNS tend to experience this.

Google DNS, with greater world presence, may be more useful for people residing in some countries. Try-and-see is a good approach. It hardly takes any effort to change DNS servers.

by seanferd

If you are being blocked by DPI or some other comprehensive method, it is unlikely changing DNS servers will help - you may never even reach them if all DNS traffic is redirected anyway.

I'm a bit confused about "splitting DNS requests". I'll just throw some info out which may or may not cover what you meant by this. But it may be handy for anyone else who reads it.

You don't want to use different DNS services together, though, if you use OpenDNS, if you use its additional features.

Yes, some router firmware (or open source replacement firmware available for some routers) can force DNS to TCP, to a different port, or to a particular server, regardless as to what is configured in TCP/IP on the computer. But normally, computer settings will override router settings. So if DNS is configured on the router, the computer should be pointing to the router's DNS address (usually its LAN address).

by alashhar

i think to diagnose my problem, i have to trace the DNS resolution in order to know if my wimax gateway enforce me to use ISP DNS or not?

please i need your help guys

by ic-it

and type
nslookup
That will return the DNS server and it's IP address.

If you type in a web address it will return the DNS server/address plus the address (ess) of the site plus any aliases

by seanferd

nslookup -type=txt which.opendns.com. 208.67.222.222

If you do not get an OpenDNS server, your DNS is forced/blocked somewhere. Post the result.

To see if you can use TCP when UDP is forced only:

nslookup -vc -type=txt which.opendns.com. 208.67.222.222

by santeewelding

I fear for you.

People in sunglasses wearing black leather coats may show up at your door.

by alashhar

nslookup -type=txt which.opendns.com. 208.67.222.222

Server: resolver1.opendns.com
Address: 208.67.222.222

Non-authoritative answer:
which.opendns.com text =

"I am not an OpenDNS resolver."

opendns.com nameserver = auth2.opendns.com
opendns.com nameserver = auth3.opendns.com
opendns.com nameserver = auth1.opendns.com
auth1.opendns.com internet address = 208.69.39.2
auth2.opendns.com internet address = 67.215.68.68
auth3.opendns.com internet address = 208.69.39.2

by alashhar

WAN Statue:
shows ISP IP addresses statue
http://www.4shared.com/file/219619207/a8f00931/WAN_Status.html

Basic Config DHCP Or Static: options to change the WAN IP configuration

http://www.4shared.com/file/219619058/46bc348b/DHCP_IP_WAN_Basic.html

http://www.4shared.com/file/219619191/9217a914/Static_IP_WAN_Basic.html

Advanced Configuration:
NAT Configuration

http://www.4shared.com/file/219619099/9d0e4b11/NAT_WAN_Adva.html

i hope these snapshots will help you to find out the problem

many thanks to all

by seanferd

"in my wimax gateway or router there is no option to just write DNS address only, it enforces me to write IP address + Subnetmask + Gateway address+ DNS address."

This sounds like you are in the LAN configuration. You need to do it in WAN/Internet configuration. And yes, some routers do not have separate settings for static DNS.

In that case, just configure on the computers. But, if you connect between computers in your home to share files, etc., or use a network printer, these will not be reachable by name (at least when using OpenDNS, without setting typo/vpn exceptions) but will be reachable by IP address.

Also, setting static IP addresses is not hard, and subnet mask is always the same 255.255.255.0 Just look at the current computer IP, assign it statically, same for next computer but add 1 to last digit of address.

by ic-it

Taken from page 1-3 of the manual.

Configuring the Static IP Routing Mode
Step 1 In the navigation tree, choose Basic > WAN, and then click the WAN tab.
Step 2 Select Route from Mode.
Step 3 Select Static Get static IP address from ISP.
Step 4 Select a NAT type.
The NAT function is enabled to facilitate translation of IP addresses, Through NAT, the host
IP address of a LAN can be effectively hidden. Thus, the security of the intranet is ensured.
Two NAT types are available:
�� NAPT
�� Cone NAT
Step 5 Enter the IP address in the IP Address text box.
Step 6 Enter the subnet mask in the Subnet Mask text box.
Step 7 Enter the default gateway in the Default Gateway text box.
Step 8 Enter the IP address of the primary domain name server (DNS) in the Primary DNS
Server text box.
Step 9 Enter the IP address of the secondary DNS in the Secondary DNS Server text box.
IP Address, Subnet Mask, Default Gateway, Primary DNS Server, Secondary DNS
Server are provided by the carrier.
Step 10 Click Apply.
----End

In the primary and secondary enter the open dns server addressess.

by alashhar

i have tried it, i wrote down the ISP IP addresses , then i entered again as static IP, the result the internet stop working.
note:
when you see to ISP IP configuration, you find that the default gateway is in different network to IP address
default GW = 192.168.56.1
IP Address = 10.6.208.68
really it is not logic, but it is working when i selected DHCP configuration
please see the snapshots for more information

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