One of my real weak points in programming is networking, so I admit that I may be a little over my head with this project. Please feel free to tell me if what I'm trying to do doesn't make any sense
What I am trying to do, basically, is run a program on my laptop (Node.JS, probably) that handles requests from a website, does some functions, and serves data back to a client running on the website. (Research tells me this is called an RPC server)
When you listen for requests in Node.JS, you specify a port and optionally an IP Address- localhost, 127.0.0.1, is what all the tutorials I've read have used, but that's not sufficient for what I'm trying to do
I've read that I'll need to set up a static IP Address? But I think those are relative to my LAN, so they'll be like 192.168.0.X. So then what would I specify for the IP for the server and the client? (I don't think the port particularly matters). Do I need a DNS?
I hope this makes sense, sorry for so many questions, thank you for your help
You can run a server on your local machine, and you will specify your local IP address for the script, like 192.168.0.x. But for this server to ever receive a connection, your client must connect to your external IP address. It is the IP address that you get from your Internet provider when you connect to Internet. If your external IP is static, i.e. it does not change, then you can use it in your client script. If the external IP changes, you must setup a DNS record that would resolve the name of your computer. DynDNS can be used for that purpose.
If you have a router, it must be setup so that it forwards connections to your laptop where the server runs. And your firewall must be configured to allow connections.
Related
app = require('http').createServer()
app.listen(5000, '75.113.126.31')
Error: listen EADDRNOTAVAIL
People say this error means I'm trying to listen on an IP address that I don't own. But that is my external IP address according to google.
Also, if I omit my IP, it only works when I visit localhost:5000 and 127.0.0.1:5000, visiting 75.113.126.31:5000 doesn't work, even though people say node should listen there too when I don't give a 2nd argument to listen. I also tried listening on IP 0.0.0.0 with no luck accessing it through external IP.
What are the possible causes? I disabled Windows firewall but that didn't help.
Your external IP and your computer's network address often have almost nothing in common. In fact it would be very unusual if they did match.
Normally you bind to 0.0.0.0 if you want your service to be available remotely.
It's also worth noting that if you have some kind of router or firewall you'll need to configure port mapping to get port 5000 to route to your local IP correctly.
ipconfig should show you your actual IP address.
You should also be aware that some routers don't handle mapping internal traffic back to a local IP. Many do, so it's not always a problem, but if it doesn't work that might be the case.
The error message you are getting is correct. I'm going to assume you are on a computer behind a router. That ip address Google is reporting is the ip address assigned to your router not your computer, i.e your computer doesn't own it. You can prove this by running the command ipconfig in a cmd prompt, finding out your eth/wifi ip address, and using that in your app.listen (it'll probably start with 192 or 10), it should work. If you want to make your app public an easier way might be to just forward the port 5000 from your router the computer running the node app. Hope this helps!
This is a "Blocked Port 80" related question, but maybe something a bit unique. I've yet to find a good answer. It's more academic than anything as I know running a production server at your house is a ridiculous idea.
I'm running a development server (LAMP) at my home but my ISP blocks port 80. The DNS for my domain is set up to "URL Redirect" to my IP and port number. My router is port-forwarding to my server, and I have Apache set up so it's listening on port 8081.
The issue is that when you access the domain, the URL in the browser is resolved from my domain name to the IP and port number, and is displayed as such. For example, you type "www.banana.com" into the browser, the site is displayed but now the URL is shown as "12.23.456.11:8081".
Is there any way to fix this so that the domain name does not become IP and port number?
Can you use Apache proxy functionality somehow?
Could you use mod_rewrite to change the IP and port number back to the domain name?
Thanks in advance!
This question has three parts. First the issue of the domain: in order to substitute a domain name in place of an IP address you need some name server that can map your desired name to an address. This is at the host level and not the port level so a domain name will encompass all ports you might host from it. If you are using your home Internet connection (which I suspect you are since you talk about a blocked port) then you need to take into account that from time to time your public IP address can change. Your options are to pay for (or request) a static IP from your ISP or use a dynamic DNS service that can rapidly update their records as your IP address changes.
As for your port number. Mod_rewrite only handles the path part of a URL, for using different ports internally you want mod_proxy. The Apache web sever with mod_proxy would be configured to listen on the public port you want (that I assume is port 80) then mod_proxy would take incoming requests and send them to another web server on a different port (or even different server). To the outside user this happens invisibly. The problem is if your ISP wont let you host your site on port 80 then it logically won't let you proxy from port 80. To get around this would be a little harder. Personally I would look at a virtualized server from people like Rackspace or Linode. You would get (for relatively little money) a fully configurable server on the open Internet with no restrictions on port usage and a static IP. Even better if you mess something up you can just virtually delete your server and start over with a fresh OS image.
Finally the clean URLs your question title suggests. It's possible this wasn't part of your actual question but just in case, mod_rewrite is a smart module that can let you map clean URLs like /cars/Toyota/1997 and turn them into more ugly requests like /cars.php?make=Toyota&year=1997. Clean URLs not only look better they make it easier to reorganize web code behind the scenes as your web site evolves.
One last thing, and its amazing to me that this question has gone so long without even a comment about this but, this question is really not a good fit for StackOverflow. Possibly ServerFault.com. Good luck! :)
I've created a simple client/server program with the help of winsock in vb6. It perfectly works on LAN but the problem is it doesn't work on WAN. All ports are already open, Firewall is already Off, I have dynamic IP so I used No-ip to get named IP address.
One more think I want to ask is , is it important to open port on both client and server? For eg- I've created the program on port 50505 and on the client computer the port is open but is it important to open 50505 on server also??
Here is my project.
If anyone could find the problem please let me know. I would appreciate a lot
Okay, first make sure that in the client side program that the Localport is not set to anything because Windows will assign it one, but the RemotePort is set to 50505. On the server side, the RemotePort is set to nothing, and the LocalPort is set to 50505.
Next you need to make sure your server has a static IP on your network.
So if your router's LAN IP is 192.168.1.1 you need to set your server's to
something like 192.168.1.50, just make sure that it doesn't get put in the range or the
DHCP server (That's the server that gives each computer a IP address from the router).
Next you need to setup your router for "Port forwarding". Be default your router had no idea what to do with data that the internet sends to it. You have to setup the router to forward any data from port 50505 to your server on your network.
While this seams really long and drawn out, it shouldn't take more than 5-10 min's to setup.
Good luck!
You need to configure the router that the server is behind to forward connections on that port to the computer running the server.
Otherwise, the client will not be able to connect to the server.
I am working on some legacy code on Windows for a desktop app in "C.
The client needs to know the geo-location of the user who is running the application.
I have the geo-location code all working (using MaxMind: http://dev.maxmind.com/).
But now I'm looking for help in getting their external IP.
From all the discussions on this topic throughout SO and elsewhere it seems that there is a way to do this by connecting to a "reliable" host (server) and then doing some kind of lookup. I'm not too savvy on WinSock but this is the technology that may be the simplest to use.
Another option is to use WinHttpConnect technology.
Both have "C" interfaces.
Thank you for your support and suggestions.
You can write a simple web service that checks the IP address(es) that the program presents when connecting to that web service.
Look at http://whatismyip.com for an example.
Note that multiple addresses can be presented by the HTTP protocol if there are proxy servers along the route.
You can design your simple web service to get the IP of the client. See
How do I get the caller's IP address in a WebMethod?
and then return that address back to the caller.
Note that in about 15% of cases (my experience metric) the geo location will be way off. The classic example is that most AOL users are routed through a small number of proxy servers. However, there are many other cases where the public IP does not match the user's actual location. Additionally, Geo IP databases are sometimes just wrong.
Edit
It is not possible to detect your external IP address using only in-browser code.
The WebSocket has no provision to expose your external IP address.
https://www.rfc-editor.org/rfc/rfc6455
You need an outside server to tell you what IP it sees.
If I create a c++ server/client application, the port I used to communicate does it need to be open on the router of the server and client machine
Or what other approach could I take? the client computer needs to receive information from the server but I am not able to have any ports opened because it is on a school network....
[edit]
Hmm My setup is a php page running on a server say when I press hello, the server makes a ssh connection through php and sends shell commands to the machine. The server is running off of a school server which I do have ssh access to and run all my things from there. The client computer will be my pc running off of the school wifi which is not connected to the server. The server will try to make a ssh connection to the public ip of my computer running off of the school wifi(no ports open/can ssh out but no ssh in). Will these methods you mention make this possible, in particular the connect.c since I can't run putty off of the server, and the connect.c I could call from the php.
The choice of language is highly irrelevant here.
There don't need to be ports 'open' on any router, unless your traffic must pass through it. On normal peer hosts in the same network (or subnet) there would hardly be any firewall policy, not even in schools.
Technically it is possible for the switch to block peer-2-peer traffic (meaning traffic not destined to the outgoing gateway), but that is not very usual.
Of course, if the school doesn't allow outbound (WAN) traffic on most ports, tough luck, and they're absolutely right :)
You can look at
ssh (with tunnels -L, -D and -R options, perhaps -o GatewayPorts on)
stunnel
connect.c
http-tunnel
All very readily googled
To establish a TCP/IP connection, only the server port needs to be accessible by the client. The connection is full-duplex, therefore data can flow from the client to the server and vice-versa.
If you are using UDP for your application, which is a connection-less protocol, what happens depends heavily on the firewall or router and whether it performs connection tracking for your service or not.
Unless you provide some additional information on your service and the network setup on both the client and the server side, we cannot provide more concrete information.