I created a vb .net app and basically it connects to the server (my brother's computer at his house) and sends messages. The problem I'm having is, we both have routers. The only way I'v gotten all of this to work, is by both of us connecting ppeo broadband and then our ips work, otherwise the "real ip" is used for all the pcs in my house. How can I connect tcp to him wothout him having to connect broadband. Because to connect broadband he needs to be connected to an ethernet port, so then he cannot be wireless.
Thanks
I don't know what you mean by "connect broadband", but if the computers are not on the same local network, and you have a NAT router in between, you will either have to connect them via a VPN (like Hamachi for example) or configure port forwarding on both sides on the routers.
See: How do you get Java sockets working with public IPs?
Some routers also have "Dynamic Port Forwarding", where if you are using, say port 8084 for your traffic, both your and your brother set your routers to dynamic port forward port 8084.
The router then listens for client computers connecting across port 8084, and when it sees that traffic, it will route traffic across that port to the client computer that first requested it.
Another popular "NAT-traversal" technology is UPnP. See this SO question and associated article for more information on how to use .NET to control UPnP. Again, router hardware must support it and be configured to use UPnP.
Edit: Untested, but you could try also to use and IPv6 tunneling software such as the one from go6 to create a public IP. This is like VPN, but one-sided, and less private.
Rather than router configuration, you could use a VPN. Hamachi is free and easy.
Related
will I need STUN/TRUN-Servers, if the devices running my WebRTC-application are in a corporate VPN, or can I expect it to just work like in LAN?
I am using the PeerJS library and the PeerServerCloud for Signaling.
if both( or all) peers are behind the corporate VPN network, then probably not. In most other cases, you would most definitely need a TURN Server,
also, if your network blocks/ restricts the 443 port to internet, you would need to connect with the TURN server through TCP transport instead of the usual UDP.
I am able to connect it if the two devices are in the same network but for example, if I use 4G on my android and turn of the wifi and try to connect to http://computer-ip-address then it just hangs and eventually errors out saying count not connect. The apache server is hosted in my local mac, and I've disabled my firewall temporarily. Any ideas on how to get a device using a different network to connect to my apache server on my local network?
You will need to configure your router so that it will forward port 80 from external to your mac.
Then, you can open http://your-public-Internet-ip on your mobile phone, effectively visiting your local web server.
If you don't like to remember your ip address, especially if you are on the go, the answer is dyndns or any free alternative, e.g. http://www.no-ip.com/services/managed_dns/free_dynamic_dns.html.
Using such a service, you will be able to enter http://yourname.service.com into your mobile phone. You will either have to configure your router to always tell this service your current IP (check your router for supported services) or run a tiny program on your mac which will handle this.
You need to enable port forwarding on your router to forward TCP 80 (and possibly TCP 443 if you are using SSL) to your web servers IP address.
Once done, you should be able to access your site via your routers public IP address.
Take note that of your web server is using a dynamic address provided by DHCP, your IP may change and this would stop it from working. I suggest you give your web server a static IP address to stop this.
You will probably have a dynamic IP on your router as well, so you can request a static one from your ISP or you can sign up for a dynamic DNS service.
If you post the model of your router, we may be able to give you more specific instruction on setting up port forwarding.
i hope your httpd.conf is set with port listening to
Listen 80
also, you can only access your site from your LAN otherwise, your server would need to be reachable from a public IP address, not a private one over an internet 4g connection, that means a diferent network
bonus points, if you try to reach your server from an external address, did you configure portforwarding on your router ?
If you could immediately and immediately connect to your localhost using your 4G network, then most likely anyone on the internet could do the same. It is important to understand that there are two components to the answer to your question:
Securing HTTP access (port 80 or whichever) from the internet. You probably don't want to open a wide door to your local network.
Configuring addressing from your client (in this case your phone) to your local computer (in this case your Mac). If the latter does not have a public IP address, then you will have to configure your client to hit your router instead, and to configure your router to forward accordingly.
Given that this is mostly system configuration work, I'm guessing that Serverfault would be a better place to find a satisfying answer.
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.
How can two computers that are on separate networks connect to each other using UDP? I know that you can do this by setting up port forwarding but I services like Xbox Live don't work through that. How is this possible and is there a way to obtain an address to another computer on a separate network?
EDIT
Ok thanks for the help I am using objc so I ended up using asyncsocket and portmapper for doing router configuration.
http://code.google.com/p/cocoaasyncsocket/
http://www.codingmonkeys.de/portmap/
First, obtaining the public IP of a remote computer:
Use dynamic dns.
Make your own protocol and run a server to keep the list of users and IP.
Working out incoming UDP packets:
Use client/server communication instead of peer-to-peer.
Use UPnP protocol (i think xbox does this) to ask your router for a port. Not all routers support or have UPnP enabled.
Use TURN/STUN protocol. This protocol has been designed to bypass UDP nat. This requires an external server, but there are free servers available.
I think there are libraries for UPnP and STUN, but i can't tell you for sure.
LatinSuD are right, STUN is good solution - check out STUN protocol implementation for iOS https://github.com/soulfly/STUN-iOS
I'm curious why is it more pervasive. Does it has a better API?
I remember long ago when i first learned about NAT (i used it for sharing a dialup 14.4kbps modem), i thought that someday every home would have a router with NAT included, but it would "obviously" need also a SOCKS process to be able to open listening ports. When broadband started appearing, it was nice to see NAT as a common feature, and I supposed that SOCKS would be an extra, and slowly become more and more common... but nothing! i had to manually forward ports. then appeared that uPNP, but very few 'serious' applications support it, mostly P2P sharing, games, and some IM.
I still haven't seen any home router to include SOCKS (apart from Linux-based firmware upgrades, of course). does anybody know why??
edit:
as Vartec noted, UPnP is a zeroconf and service discovery, not proxy service. now i know that what i'm referring to is IGD protocol, the NAT traversal service present in home routers, and discovered via UPnP. so, my question would more properly be "Why IGD/UPnP instead of SOCKS?"
SOCKS has limitations compared to UPnP. Generally SOCKS requires configuration on each client and isn't transparent to applications (system-wide socket SOCKSification isn't installed/enabled by default on Windows), while NAT even without UPnP mostly works transparently and without any additional client configuration for outgoing TCP sockets and outgoing UDP.
NAT with UPnP also supports server TCP sockets better than SOCKS: SOCKS can only accept a single connection with its BIND request, which is okay for receiving a single TCP connection in a protocol like FTP, but useless for running a server that needs to accept many connections from many clients. SOCKS 4 also had a 2 minute timeout on the BIND request, but a server generally cannot know when the next client will try to connect.
Low-level TCP settings (eg. TCP Nagle, traffic class) also don't work across the SOCKS proxy, but they work through a NAT.
As far as I know, UPnP is zeroconf discovery type of protocol for devices in local networks, while SOCKS is tunnel-proxy server. They are completely different, actually I don't see anything, that they would have in common.
these are two different things, socks is a protocol that allows you to route tcp and udp (socks v5) through a proxy server and it's for outgoing connections, routers dont have anything to do with this (except they are acting as a proxy too)
the IGD of upnp is an 'api' that allows you to tell your router that you want to open a port and foward it to a computer, this is for incoming connections.. my linksys came with upnp enabled by default and one app i know to use this is msn messenger (maybe only for file transfers)