Is there a way to setup an TCPListener to use an website ip address instead of an computer ip address. For example, instead of using 127.0.0.1, use 74.125.233.95 (Google's Ip address. Just used here for example). Here is my code I tried :
Dim hostname As IPHostEntry = Dns.GetHostByName(TextBox1.Text)
Dim ip As IPAddress() = hostname.AddressList
Dim port As Integer
Dim localAddr As IPAddress
Dim server As TcpListener
Try
port = 8080
server = New TcpListener(ip(0), port)
server.Start()
RichTextBox1.AppendText("Listening on : " & ip(0).ToString & vbNewLine)
Catch ex As Exception
RichTextBox1.AppendText(ip(0).ToString & " : " & ex.Message & vbNewLine)
End Try
The above code outputs :
74.125.233.95 : The requested address is not valid in its context
Is there any way to do this using TCPListener or some other method?
EDIT :
See the thing is, I want to create an app which can be controlled from anywhere in the world over the internet. I want to keep it as simple as possible so the user doesn't have to define port forwarding when using an router and also so that the firewall doesn't block it. So the best approach for me is that the app will listen for commands over my websites domain name.
Your code isn't responsible for defining the IP address, it only binds to IP addresses that are configured by the operating system on the computer's network interfaces.
When you open up a port and listen with TcpListener, you are binding to an existing ethernet interface with an IP address (or all of them if you use 0.0.0.0 / INADDR_ANY).
EDIT: OP clarified, he wants to receive requests from and/or remote control an application he distributes without requirement that the user configure anything special like port forwarding.
The best way to do that is to use "push". Make all of your apps phone home.
You can do this without initiating a TCP connection from a central server to your app, instead have the apps connect to a central server on a public address and the server can then control the application by pushing commands/requests. The point is, this works from behind proxies and NAT firewalls without port-forwarding on the user's network. Your server needs to run on a public IP address. It doesn't really matter which end initiates the connection, once the connection is up, it is bidirectional.
I want to create an app which can be controlled from anywhere in the world over the internet. I want to keep it as simple as possible so the user doesn't have to define port forwarding when using an router and also so that the firewall doesn't block it. So the best approach for me is that the app will listen for commands over my websites domain name.
No, that's not the best approach at all. The best approach is for your application, and those who wish to control it, to connect to a central server that you provide and manage. The central server would relay the requests.
The approach that you are attempting makes no sense and will not work.
Related
this might sound a bit amateur-ish but I'm in a bit of a situation here.
So I created myself a website and managed to get it working on localhost, I tried port forwarding ports 80,443 but nothing helped, So next thing I'm googling around and I read about ngrok and it actually worked. Got it working on a long randomly generated domain but the problem is that I want to use the one that I have from no-ip.com. How can I do that please? I'm very lost here.
Software being used: Xampp (Apache,MySQL)
I've reserved a DHCP ip-address for my PC in my router's settings, hopefully that helps? I don't know. Help me internet.
There are a whole bunch of possible reasons that this might not work. Here are a few of them.
Your ISP
Even if you have port forwarding set up properly on your router, it is still possible that you cannot do what you want.
First, many ISPs block serving websites from residential internet connections. Connections to port 80/443 will never even reach your router. You might try experimenting by forwarding a different port number (such as 8000 instead of 80) to see if the traffic can get through on that port. (However, that will not work as a practical solution since your users will not know to use an alternate port and your ISP can choose to terminate your service if you are violating the terms of your agreement.)
Second, due to the exhaustion of public IPv4 addresses, some ISPs are implementing Carrier-Grade NAT (CGNAT, a.k.a. Large-Scale NAT - LSN). Instead of giving your router a public IP address, they give your router a private IP address inside their network. Once again, connections to port 80/443 (or any other port for that matter) will never reach you. You can check if you are behind CGNAT by going to your router's setting and finding the public IP address, then going to https://whatsmyip.com/ and seeing if it is the same or different. (In theory, you should be able to tell that you have CGNAT if your router's IP address is between 100.64.0.0 - 100.127.255.255, but in practice some ISPs use other private network ranges too, such as 10.0.0.0 - 10.255.255.255.)
The reason Ngrok works for you is because Ngrok opens a tunnel from your computer to their cloud servers and sends the traffic through that tunnel.
DNS
You mentioned in the comments that you have the DNS set to resolve the private IP of your computer. That certainly will not allow users on the public internet to get to your site, because they cannot connect to your address.
However, you also mentioned in the comments that if you change the DNS to point to your public IP, it doesn't work from either inside or outside. This could mean your problem is one of the ISP issues described above. It could also mean that your router does not support Hairpin-NAT (a.k.a. NAT Reflection), which is how the router would be able to redirect local traffic back to the local server instead of trying to send it out over the internet.
Firewall
Your computer's firewall can look at the source IP address of the incoming traffic, and it might be set not to allow external access to your web server. DO NOT DISABLE YOUR FIREWALL to try to get around this. Instead, you need to add a specific exception to the firewall rules to allow the incoming traffic. How you do this will depend on your operating system.
In the WebRTC signalling process, I have to find my own public IP address with my port by doing a request to a STUN server. But does it really need to be this complex?
Couldn't I just send a request to the router of my subnet and get its IP address and the port it opened for me? Or even better, I store directly my public address in my computer and the router notifies me whenever it changes. The browser would give an API to get this public address directly. No need to use a STUN server. Why don't we do this instead?
Thank you for your help.
These are all great questions.
Couldn't I just send a request to the router of my subnet and get its IP address and the port it opened for me?
There's an old protocol called uPnP that will dynamically open a port mapping for you - provided the router supports it. A lot of routers used to support it. Not sure how standard it is now.
Even if routers were intelligent and there was a standard signaling mechanism in place, STUN (or something equivalent for STUN is still needed) for the following scenario.
Carrier NAT is when your ISP is sharing a public IP address with multiple routers. That is, your router's public IP address as configured by the ISP when it starts, is really just another private IP address. Upstream, there's a "bigger router" that is sharing the public IPv4 address with multiple other customers. That is, your PC might think it's IP address is 192.16.1.2, and your router reports that it's own IP address is 10.0.0.2. And the actual public IP address, 1.2.3.4, is shared with other customers. STUN solves this problem because the outbound packet to the public STUN server will go through both NATs - creating port mappings along the way.
Or even better, I store directly my public address in my computer and the router notifies me whenever it changes
Because establishing an effective P2P/WebRTC connection is more than knowing your public IP Address. It also involves knowing what "port" to use as well. While most routers will attempt to preserve the local port of the socket the client PC is using in the mapping (e.g. 10.0.0.2:9876 maps to 1.2.3.4:9876). This isn't always the case - another node could be using port 9876 on your network and/or many NATs just pick a randomly available port for the mapping. At the end of the day, you have to signal to the other side of your P2P/WebRTC connection "which IP" and "which port" to use.
The browser would give an API to get this public address directly.
There are plenty of sites such as whatismyipaddress.com that will tell you your IP address. But if there's a HTTP proxy server involved (explicitly configured on the PC or silently deployed on the network), the web service will only see the proxy IP address. Further HTTP(S) is a TCP based protocol. STUN and WebRTC are UDP based.
I have created a web application in glassfish and I can access it on my LAN.
How can I access the web application from a remote location over internet?
I do not have static IP.
Please reply.
Thanks.
Steps :
Creating virtual DNS(Domain name server) Server on your machine.
Port Forwarding.
Reference https://cookbook.fortinet.com/port-forwarding-60/
Remote Desktop Connection enabling.
Creating Inbound Rules. Reference :
https://www.howtogeek.com/112564/how-to-create-advanced-firewall-rules-in-the-windows-firewall/
Creating account on www.noip.com and create custom host and download DUC (Dynamic Update Client) Software.
Some more steps may have it depends on your LAN Router and firewall configuration.Use http://ifconfig.me/ to get your public ip.
Access from outside your machine should be configured by default. You may check if it is so in admin console, at Configurations->server-config->Network config->Listenters. There should be one listening on the desired port (like 8080) and be bound to 0.0.0.0 address.
To easily access something behind a dynamic ip you need something like http://www.noip.com/ or http://www.dnsomatic.com/ (I took these from my router's control panel)
I did this recently,
first you need to use port forwarding on your router, access it by typing your default gateway path, mine was 192.168.0.1 then go to "advanced settings -> Port forwarding". Simply enter the details that are asked for, I set mine to HTTP using port 8080, yours might be different. Protocol is TCP. The IP address it asks for is your local address.
For quick testing you can disable the firewall on your machine and then you can search on google for your Public IP address by typing "what is my IP".
Then type your ip into the browser and the port number "ipAddress:portNumber"
You should see the glassfish welcome screen if it is successful.
After that you might want to enable your firewall again but then you have to add an inbound rules to allow the port to be used:
Setting Windows inbound rules
Then you still have one last step to perform, allowing glassfish to access the resources on your machine: Adding glassfish to allowed programs
Follow the instructions on adding java.exe only.
I have created a simple tcp client-server application in vb.net. Everything works fine when i set local host (127.0.0.1) as the ip address. I wish to make a connection to a remote machine (keeping client at my machine and server on the other - or vice versa).
EDIT:
ok, the code of interest is as follows:
the server:
Dim server As TcpListener = New TcpListener(IPAddress.Any, port)
the client:
Dim theip As IPAddress = IPAddress.Parse(TextBox1.Text)
client = New TcpClient(theip.ToString, port)
Now, what should i enter in "TextBox1.Text" if i have my client on a remote machine (connected over internet) and server at a different computer (whose external IP address is known)?
Can i enter the external IP address of the machine running the server directly in the text box? Also, do i need to take care of things like "port forwarding" / "let firewall allow the connection" and all? If yes, can you please guide me or link a tutorial so that my application does this automatically or is there an alternative approach to achieve this and so that port forward is not required? Thanks a lot!
You say the other machine has an external ip address. This implies it also has a local ip address; ie it is behind a NAT firewall or similar. In this case, you will have to configure the firewall to allow communication to take place, eg by setting up port forwarding.
Applications such as MSN Messenger, VOIP clients etc have elaborate mechanisms to negotiate this automatically, but they're often not very successful.
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.