I'm currently having intermittent issues with Safari loading web pages due to it's disagreements with my default DNS addresses. I can use custom DNS with no issues, aside from my VoIP application not connecting when I do switch my DNS. I've managed to identify the specific ports that are connecting to another set of specific ports and IP for the VoIP application, and I want to adjust my settings somewhere so that I can route those specific addresses.
Currently, to identify the addresses for the app, I type sudo lsof -n -I TCP in terminal and I can identify the app is using the following below:
TCP 10.5.9.151:50036->xxx.xxx.x.xxx:https
TCP 10.5.9.151:50094->192.168.5.173:5448
TCP 10.5.9.151:50093->xxx.xxx.x.xxx:https
TCP 10.5.9.151:50095->192.168.5.173:5448
TCP 10.5.9.151:50098->192.168.5.173:5448
TCP 10.5.9.151:50099->192.168.5.173:5448
TCP 10.5.9.151:50100->192.168.5.173:5448
By default, three DNS addresses are loading in my preferences, all of them private/local network. If I manually add those three DNS addresses after manually adding Cloudflare's DNS, the VoIP will not connect. If I rearrange so that the Cloudflare DNS is last on the list, Safari reverts back to intermittent connection and the VoIP works fine.
I don't have this issue with Chrome, but I'd prefer to remain on Safari. If I have to go without the VoIP application, though it's handy to see who's calling as the phone is out of view in my normal workflow, it's not the end of the world. I'm marginally familiar with Terminal, but I don't know how to modify my hostfile without risking botching my computers network connection. Would be nice if there's a GUI solution that's free. I tried Core Tunnel but I kept getting connection refused messages, likely because of poor configuration on my part.
Related
I have developed a WebRTC based application along with Kurento-Media-Server.
Problems with this application is:
It works but only on open network (i.e. if run on a network without firewall).
When in firewall it runs sometimes (once out of 10 attempts).
I have tried several things with the firewall, I have disabled all kind of incoming/outgoing traffic. I have created a port-forwarding for my application as well as Kurento-media server.
I am not sure how much useful this information might be but I am deploying my
application on the same physical box along with Kurento-Media-Server. I have configured google's STUN server on my client.js, I have also configured same STUN servers on kurento using code. I haven't configured TURN server.
Just confirming this, signaling server can be behind firewall along with rest of the application, correct?
I am not sure what to look for now, any help in this area would be great.
EDIT-1
From this link I learned that my current network on which my isn't working it has issues with plain websocket connection, it doesn't allow it, it only allows secure Websocket connections.
EDIT-2
Image of netscan:
In my phone network where my app works fine I see all greens in Websocket's "plain" column.
EDIT-3 Solved
Finally found the problem, We were using a router for testing and development and I found that the router had issues, I used LAN cable on the same router and everything worked fine. Calls from application were working just fine. Firewall related details help in configuring the firewall later on.
Based on your problem description it seems all the UDP traffic is not open in your firewall. WebRTC media run on UDP ports.As you mentioned it works one out of 10 times whch means only few UDP ports are open in your firewall.You are lucky when traffic comes via tose ports.You can open port-range in your firewall and configure the same in kurento-media-server config.Your job should be done.
Even if you configure TURN server you need to open certain ports for outgoing and incoming UDP traffic.For TURN server default port is 3478 or 8443 for sending data towards it but for incoming traffic you need to configure port-range on your TURN server and open those ports in your firewall. Always remember TURN server is assured way to connect but it's always costly.
I want to make my site available world wide. Im using xampp server for hosting. I have no access to any kind of servers and modems. Situation is shown below:
My site server has local ip assigned by wifi router and it runs Windows 8.
Remember I have no access on any kind of servers and modems so port port-forwarding is impossible (out of my scope).
Its actually difficult, but not impossible.
One way, I would approach this is:
I would host a page on internet.
Then take request and store it in database.
One of my program will always be running from my computer.
Then check for request and curl the request to localhost. For this you may use Node.js (taking data from database using GET method and curl it to localhost).
This is the best I could think of. And I am working on it, when the code is ready I'll make it open source and notify you :)
But still, it's difficult, as you need to put user's request to sleep for 2 seconds and then transferring it.
Its slow, but may work out for you.
Disadvantages:
Program will be very slow and memory usage will be more.
Breaking may happen many times.
High bandwidth wastage
If not encrypted, MIM (Men in Middle) may possible.
Advantages:
Indirect method of hosting
Need not to worry about your code being lost.
I am looking forward for a better alternative and I would like to keep this question for bounty once again.
If you cannot open the necessary ports within your LAN you will require access to an external server. However, the external server does not need to host any code, e.g.
Create a Linux based ec2 instance using Amazon's free tier.
Install a package to redirect remote to local ports:
a. using socat:
Install socat using your distributions package manager
Connect via SSH: ssh -N -R 42500:127.0.0.1:80 -o ServerAliveInterval=60 ubuntu#xxx.xxx.xxx.xxx -N -R 8080:localhost:80 "socat TCP-LISTEN:8080,fork TCP:127.0.0.1:42500"
b. using a webserver and reverse proxy:
Install apache or nginx and any required reverse proxy modules and configure your VirtualHost to proxy requests to a local port, e.g. :8080 -> 127.0.0.1:42500
Connect via SSH: ssh -N -R 42500:127.0.0.1:80 -o ServerAliveInterval=60 ubuntu#xxx.xxx.xxx.xxx
Your machine is now reachable via the ec2 instance http://xxx.xxx.xxx.xxx:8080/.
I occasionally use this technique when debugging web service callbacks.
Update 17-02-2014
If you are a Windows user you will need to install a third-party tool to support ssh. Options include:
cygwin
git bash
PuTTY
PuTTY is the easiest choice if you are not familiar with *nix tools. To configure remote port forwarding in PuTTY expand the following setting: Connection -> SSH -> Tunnels. Given the previously described scenario, populate Source port as 42500, Desination as 127.0.0.1:80 and tick the Remote option. (You may also need to add the path to a PuTTY compatible private key in the Connection -> SSH -> Auth tab depending on your server configuration.
To test you have successfully forwarded a port, execute the command netstat -lnt on your server. You will see output similar to:
tcp 0 0 127.0.0.1:42500 0.0.0.0:* LISTEN
Finally you can test with curl http://127.0.0.1:42500. You will see the output of your own machines web root running on port 80.
if you don't have a public IP address and cannot use port forwarding it is impossible to host the site
As people have said you need a public IP address. However, even if you did you should not use xampp as a public server, as it is designed for development and therefore has some security settings disabled.
I would recommend buying some shared web hosting, and uploading it to that. (you can get cheap hosting if you google 'shared web hosting', plus free .tk domains are avaliable: http://www.dot.tk/)
Do your company has any vpn network?
If it does and you have access to the vpn network, you can include your server to the vpn network and your guest will only need to login to your company vpn network then access your site like in a local network without using port forwarding. And since your data is very confidential, I assume that using vpn will also help to increase the security of your data.
Please correct me if I'm wrong.
Thank You.
What you are asking is not possible without port forwarding.
Lets break it into steps.
To host your site locally you will need a IP that is static so that
users can access it specifically.
You will need a domain so that it can be converted into user friendly name.
A 24x7 Internet Connection is must! You added a Wifi Router in your Diagram and most of today's router are capable of port forwarding.
What i will do in your scenario is:
Instead of using XAMP, i will install WAMP because i am more familiar with it and easy to configure.(totally personal preference)
Then i would set my server "ONLINE".(Google how to set WAMP server online)
Forward port "80" from router settings to my local computer ip address.(mostly it is tagged as "Virtual Server","Firewall","Port Forwarding",etc vary router to router in settings)
Suppose you have a local ip "192.168.1.3" and global/router IP "254.232.123.232" then you would redirect all the HTTP request done towards router to your local IP.
[[[[254.232.123.232]]]] --+ :80 +-- --------->192.168.1.3
That is good for now, but then you will need to tackle dynamic IP problem of router. But don't worry, thanks to some free sites that will be easy!
Go to no-ip.org -> Setup Account -> and create a entry, just a subdomain for now to test whether everything is working fine.(subdomain like mysite.no-ip.org, later purchase a real Domain)
Input your IP address there(Router IP) and download its application which will automatically update their server if your local IP changes.
Wait for some minutes and Voila! Your site is live.
I'm trying to transmit data in UDP datagrams into a client in external location to a pc in my local lan.
But my network is over a ADSL modem sending to a pc with Slackware, this pc redirect packages into other pcs.
I'm using socat to redirect UDP:
socat -v udp-listen:1935,fork,reuseaddr udp:192.168.0.40:37000
In LAN the conection is fine, but external IPs don't work.
Somebody help?
I don't think socat is the culprit, however consider to use stone instead of socat, because using a fork() for each received packet is a bit weird. Stone is called in your case like this (I think):
stone -n -d -d -d -d 192.168.0.40:37000/udp 1935/udp
Now why external IPs perhaps do not work. Sadly your text does not tell much about your setup, so I have to guess:
It depends on your firewall/modem/router if it is able to forward UDP packets. Usually, if you initiate the UDP requests from the inside, the router will open a NAT connection, which often means, that not only the source IP of the packets change, but the source port as well. As UDP is connectionless, UDP NAT connections usually time out very quickly, say after 5 minutes, if no data is transferred on them.
If the UDP must be opened in the opposite direction (from Internet to Intranet), the router usually discards all the UDP packets coming in from Internet, because it does not know where to forward them to. A router cannot just choose some arbitrary machine, this would be a security hole. So in the "Internet connecting to a machine behind the router" you must open the UDP port on the router and let it forward to the right machine. In that case packets sent from your internal machine will get their source IP and the source port rewritten, the machine on the Internet always will see the packets as coming from your router. So except for the additional rule in the router this case is the same as the outgoing case.
Note that there are several different ways how to make NAT (symmetric, etc.) and several methods on how to open a port on the router (Config, UPnP, etc.) so the ways to poke some holes into it always depends on your hardware capabilities. This all cannot be answered here.
Some other ideas what might go wrong as well:
Some UDP protocols encode IP addresses within the payload. In that case it is not enough just to forward the packets, you must change the payload as well to correct the IP addresses exchanged to enable all machines to talk together. Such UDP protocols are badly designed, anyway, because you never should assume that two arbitrary machines can directly talk with each other, so all good protocols should support easy proxying.
Some ISPs filter certain UDP ports, for arbitrary reason. If you have problems talking from Internet to your DSL, try with two external machines directly connected to different ISPs. If these can talk via UDP check if you can talk from your Intranet to one of the external machines. If this still works, this means, that you can talk backwards as well, as usually UDP is not a directed protocol, but if there is some NAT involved you somehow must make sure that the communication ports stay open.
Mobile Internet plans often do not support P2P. This probably means, those plans do not support Internet at all, as IP, by definition, is P2P. What the ISPs really want to say with "no P2P" is (my guess), that connections from Internet to the mobile device are not supported. In that case you always must initiate a connection from the mobile device, so you cannot use push methods (Internet to Mobile), the mobile device always must pull (data from Internet). Some broadband/cable providers might do the same. Usually you can see this if your ISP hands out an IP in the 10.x.y.z range to you.
There might be another trick how to get the connection working:
Ask your ISP to get some IPv6. Perhaps use 6to4. With IPv6 you eliminate NAT completely, your local LAN then directly interconnects to the Internet on IPv6. Be sure to activate your firewall/iptables on your Intranet host on the IPv6 interface, else you might see Intruders very quickly.
HTH
What kind of IP address does whatismyip.com provide?
How can I get it using VB.Net code?
Also what is IP port?
Thanks
Furqan
PART 1
Okay, let's pretend you have a router in your house and that you have several computers in your house all connected to the internet through your router.
In order for the router to know where traffic goes on your network, it assigns unique IP Addresses to all computers on your home network (Usually beginning with 192.168.x.x). These IP addresses are local ip addresses, meaning only your router and computers/devices connected to it in your house knows about them. If you open a command prompt and do command IPConfig you will see the IP address that your router has assigned your computer.
So what is the IP address that WhatIsMyIP.com showing you? In much the same way that your router assigns addresses to all the computers on your network, your internet service provider hands out unique IP addresses to all of their customers. Now, because you have a router, the only thing the ISP can see on your network is that router and your ISP assigns an IP address to it. This is why routers are also called hardware firewalls, because people on the other side of it, can't tell how many computers or devices are connected to it.
What this means is, when you are visiting websites on the internet, the only IP address they see is your routers external IP address (the one assigned by your ISP). So no matter which computer in your house you use, the website wouldn't know the difference because all it can see is your router's IP address. Go ahead and try it; go to www.WhatIsMyIP.com on several different computers in your house. You will see that they all show the same IP address. However, if you did IPConfig in your command prompt on each computer, that shows you the local address your router assigned and it would be different on every computer in your home.
So, now that you understand the difference between local and external IP addresses, how would you retrieve your external IP address in VB or C# .net code that is running on your PC? Well the only IP address your computer is actually aware of is that local IP that we talked about. The only way you can see your external IP address is to go to a website that tells you what address the request came from (which would be your router's IP address).
What you would need to do is write up some code in your VB.net program that would navigate out to WhatIsMyIP.com (or some other website that can give you your IP address) and tell the code to grab it. I have written a web service located at http://www.u413.com/test/terminal/myip that returns only your IP address as the entire HTTP response. Find something similar though for your application because this little sample will not stay there forever; I only put it up there as a temporary example on a domain I already own.
Visit http://www.vbdotnetheaven.com/UploadFile/kbawala/WebRequestClass04182005054320AM/WebRequestClass.aspx to see how to make web requests from code running on your computer.
NOTE: You may not be aware of what DNS is either if you are unaware of how IP addresses work. Everything on the net has an IP address, including the servers that serve up website pages. But what a pain that would be, trying to remember up to 12 digit IP addresses for all your favorite websites. That is what DNS servers were invented for. DNS servers take a domain name (e.g. www.facebook.com) and translates it into the correct IP address. That way all you need to remember is facbook.com instead of 69.63.181.12 (this is facebook's IP address. Go ahead, try it! Put that IP in your browser's address bar and you will see facebook.), domain names are much easier to remember!
If you want to see the IP address associated with a website, open up a command prompt. Once the prompt is open type PING [websitedomain] (e.g. PING Facebook.com) and your computer will send 4 test requests to the address which is displayed for you.
PART 2
Let's pretend your IP address is like the address of an apartment buliding. The pizza delivery boy needs to know the address to the apartment building in order to deliver your pizza. But what is he going to do when he gets there? There are hundreds of doors/apartments to choose from. He needs to know the apartment number (port number on your computer).
Your computer has thousands of ports, and programs can listen on any one of them for requests from the outside world. When you go to a website almost all websites are served on port 80. Port 80 is the default port for web pages. When you go to facebook.com you are actually going to facebook.com:80, you just don't see the :80 because it is implied since it is the default. If I put up a web server, I could decide any port to serve websites on. If I served web pages on a different port than port 80, then you would have to include it in your URL. http://www.SomeDudesCustomWebServer.com:1337.
Outgoing requests use a port too, but that one is usually unimportant and your computer just picks one that is available. So when you go to Facebook.com, the facebook web servers are all serving up pages over port 80, but the port your computer opened up to send the request does not have to be port 80 because it picks an available port and then sends the port with the request. Then when facebook sends its response, it sends the reply back to the ip address and port that made the request.
Outgoing ports are only used for the duration of the request. Ports that must listen for connections must stay the same otherwise the computers making requests would have no idea what port to send the request to.
Easy huh!
Hope that helps you understand a bit better.
EDIT:
Port Forwarding
Okay, in light of the chat application you want to use/create, if you want it to communicate over the net you'll have to learn about port forwarding. Basically, because all you could see of your friend's network would be his external ip address, you will have to use that address to connect to his chat server (or vice versa if he is connecting to your chat server then it will be your external IP). Because of this, the connection request would only get as far as the router that has the external IP, but it would not know what computer on the network to forward the request to.
You will need to access your router's firmware and set up port forwarding so that the router knows to forward requests on a specific port, to a specific computer on the network. Visit http://portforward.com/ for more detail on how to setup port forwarding.
EDIT 2:
Firewall
When setting up stuff to communicate with your computer using your PC, you may start getting frustrated that it just won't connect. What is likely stopping you is your firewall. By default, most ports on your PC are completely blocked by the windows firewall. For each port that you want to communicate on you will want to go into the firewall and create a rule that will open up the port. Go here http://www.top-windows-tutorials.com/windows-7-firewall.html for a video on how to use the windows firewall. I did not watch it, but it is what came up first on a google search.
Do not simply disable the firewall. Even though this is an easy and quick solution to open up all your ports, you are leaving yourself open to attack. Viruses love to set themselves up in your computer if they can and listen on an open port for a connection from their beloved creator so he can obtain access to your PC. Only open the ports you need.
UDP vs TCP
When opening and forwarding ports you may notice that it asks for UDP (User Datagram Protocol) or TCP (Transmission Control Protocol). What they stand for may not make sense but all you need to know is this: UDP is for single packet transmissions which means that two packets sent by a pc may or may not be related to each other. These types of data packets are usually used for broadcasts on a local network. An example I would use is LAN games. When you host a game on a LAN the other computers/devices can see the name of the game and join it. That is because the computer hosting the game is transmitting a UDP broadcast across the entire LAN so that any devices can see the game. Those UDP transmissions usually contain the name of the game and the connection info required to connect to the game.
TCP is for continuous packet transmission. TCP requires an established connection, any packets transmitted on this connection are always related to that one connection/request. To continue my example from the last paragraph, once you click connect on the LAN game, your computer then establishes a TCP connection with the host and uses that connection for the duration of the game or games. TCP is the most commonly used connection type and your chat program would likely communicate over TCP, especially if you are connecting across the net because UDP broadcasts are useless across the internet. UDP is only really useful on a LAN.
You should be safe forwarding and unblocking only the TCP ports, but sometimes when I'm unsure I just do both UDP and TCP just to be safe. In fact, many routers and firewalls have 3 options: TCP, UDP, or Both which saves you from having to create two rules for both types of the port.
When in doubt, open/forward both.
What's my ip provides your IP v4 public address.
It's really easy to retrieve it, this topic explain how to proceed : How to get the IP address of the server on which my C# application is running on?
The code is only a few lines long, so the language (c# in this example) does'nt matter.
They provide your external internet facing IP.
This IP will depend on how you connect to the internet. If you connect straight from your computer to your ISP without any kind of router or firewall in between, it might be the same as your internal IP, but in most circumstances this will not be the case.
If you're at home and you've connected via a router of some kind, then you might be able to query it for the IP, but there is no standard way of doing this.
There is no standard way of getting hold of your external IP from the client it self. If you've got access to a server on the internet where you could deploy some code you could connect to that server from your client PC and ask it what IP you're connecting from.
IP Port Numbers
I also needed external IP using command line, but because I didn't find it I wrote small application using vb.net. You can use reflection for source code or ask on app home page for it. Basically application opens web page that provide your IP and parse it using regular expression, but because is designed with this purpose uses many "tricks" for this (can use more web pages at once, uses fastes page, etc). Check source for details.
I am looking for a way to forward traffic from an application which goes to the web over port 443 to an instance of Fiddler running on my computer. Fiddler does not see this traffic while a packet trace application verified that the traffic is going out.
The application is foreign and I am not able to modify how it requests and it is not going through Internet Explorer (or apparently any other browser). If this app is going to an ip address (ie. 66.xxx.xx.xx port 443) or to a named host (ie. https://www.anysite.com), is there a way to tell my computer to forward this traffic to Fiddler, ie. to localhost port 8888?
I am not sure I am using the right terminology to describe this but and ideas would be appreciated!
Thanks,
David
If you can't get the application itself to send traffic to localhost on a specified port, then you need something lower level than Fiddler. Try WireShark.
http://www.wireshark.com/
#David: What's the application in question? Virtually all applications can be proxied, because those that can't aren't usable from most corporate networks. In some cases, you have to make minor changes to the environment (e.g. setting the proxy for the JVM). Some details are here: http://www.fiddler2.com/fiddler/help/hookup.asp
Using Netmon or Wireshark, you should be able to determine whether or not the application in question is making a request directly to a fixed IP address, or more likely, doing a DNS lookup first. If it's doing a DNS lookup first, you could edit your Windows Hosts file so that whateverthehostis.com points at 127.0.0.1. Because the hosts file only maps host to IP and not port to port, you'll need to adjust Fiddler to run on the target port that the application is looking for (use Tools > Fiddler Options for that).
Now, if the traffic is HTTPS (and I'm guessing it is) you're going to have a problem at that point, because Fiddler currently can only act as a HTTPS endpoint when it "knows" that the traffic is HTTPS by virtue of the client having opened a CONNECT tunnel first. This is something that could be adjusted in a future version of Fiddler, but it's not a common request.