I was wondering what exactly the standards say about using IPv6/IPv4 tunneling to send a DNS query to a DNS server. Is this a valid thing to do? Does anyone know the RFCs (and sections if possible) that talk about this?
Thanks.
Of course it is possible. Once you have a tunnel, you can do it whatever you want, concerning IPv6.
If you tunnel the trafic f a complete network, other PCs maybe don't even know that they are behind a tunnel.
My PC here, for example, has some IPv4 and some IPv6 entries in the /etc/resolv.conf.
Related
I use Chrome/IE to connect to the internet, but it does not work. When I ping the url, it works well! Someone can help.
Thank you
I don't know your setup and your question is very generic, but probably it is a problem with the DNS servers, you can reach the IP address but there is no way to translate the addresses you type in the browser bar to ip addresses.
Configure your routers\firewalls\network interface card with the correct DNS servers.
I might sound like noob, I'm real new to this.
I use my college LAN to use internet. My college has blocked many websites(movies, games, porn etc).
I'm not sure about the way that it works. VPNs don't connect. And entering directly the IP addresses of websites is also blocked.
so what i was thinking is that if we could somehow type in google.com and make the DNS translate the ip address of steam.com, could that help bypassing?
If the websites ip are locked, this is not a dns filtering so you have nothing to do with dns. If vpn don't connect, some ports are probably locked. So, you should find a vpn that use the port 443 or use a webproxy.
I am currently making a website. I'd want people to try it out. They can do so right now if I send them my IP and port and they put it in the URL. My computer acts as the server right now.
Is there a way to use my computer as the server but without actually sharing directly my IP? Some kind of rerouting. I am not looking for something very secure, I am only looking for a solution that doesn't involve putting my IP in the URL.
You can register a domain name (or use a free equivalent like FreeDNS), but your IP will still be visible to anyone who pings you server. You could rent a VPS and use that to proxy requests to your server, or you could use an anonymizing service like Tor to keep your IP hidden, but there's really no reason to go through all that trouble. If you're worried about people having your IP address, there's no reason to, because there's not really much people can do with it. If you're looking for an easier way for you to share it and for people to remember it, I suggest FreeDNS or No-IP.
You might want to look into using ngrok - https://ngrok.com/.
It allows you to run general internet traffic to any port on your local machine, via somesubdomain.nkgrok.com. Also, it works if you're behind a firewall - you just open up a connection to ngrok from your computer, and ngrok will forward incoming traffic to your computer through that connection.
It is very interesting that I can actually make a mVoIP service from the scratch. I finally could make a call using OpenSIPs source through SIP protocol. I used external STUN server that helps me to find users' private IP address behind NAT firewalls.
However, the free external STUN server cannot find user's IP address to make a call when a smartphone is on 3G or 4G network. As a programmer, I won't give up to make a mVoIP service. However, I need a help at this time from you guys.
Is there a good way to solve this problem? Thank you.
There can be two problems here:
-you can't find the correct external address behind all kind of NAT. This depends on the NAT type only
-some mobile operators blocks STUN. You can add some modified stun or a simple encryption as a workaround
I actually could find IP address using external STUN server, however it failed to connect media session on 3G/4G network. So, I decided to use RTP proxy to make a SIP call.
OpenSIPs provides RTP proxy module, and it helps to make a call without NAT issue.
I am implementing a dns client, in which i try to connect to a local dns server, but the dns server is returning the message with an error code 5 , which means that its refusing the connection.
Any thoughts on why this might be happening ?? Thanks
DNS response error code 5 ("Refused") doesn't mean that the connection to the DNS server is refused.
It means that the DNS server refuses to provide whatever data you asked for, or to do whatever action you asked it to do (for example a dynamic update).
Since you mention a "connection", I assume that you are using TCP?
DNS primarilly uses UDP, and some DNS servers will refuse all requests over TCP.
So the solution might be as simple as switching to UDP.
Otherwise, assuming you are building your own DNS client from scratch, my first guess would be that you are formatting the request incorrectly. Eventhough the DNS protocol seems fairly simple, it is very easy to get this wrong.
Finally, the DNS server may of course simply be configured to refuse requests for whatever you are asking.
explicitly adding the network from which i wanted to allow-recursion fixed this problem for me:
these two lines added to /etc/bind/named.conf.options
recursion yes;
allow-recursion { 10.2.0.0/16; };
Policy enforcement?
The DNS server could be configured to accept only connections from certain hosts.
Hmm, if you're able to access StackOverflow you have a working DNS server SOMEwhere. Try doing
host -v stackoverflow.com
and look for messages like
Received 50 bytes from 192.168.1.1#53 in 75 ms
then pick the address out of that line and use THAT as your DNS - it's obviously willing to talk to you.
If you're on Windows, use NSLOOKUP for the same purpose. Your name server's address will be SOMEwhere in the output.
EDIT:
When I'm stuck for a DNS server, I use the one whose address I can remember most easily: 4.2.2.2 . See how that works for you.
You might try monitoring the conversation using WireShark. It can also decode the packets for you, which might help you determine if your client's packets are correctly encoded. Just filter on port 53 (DNS) to limit the packets captured by the trace.
Also, make sure you're using UDP and not TCP for queries; TCP should be used primarily for zone transfers, not queries.