Two router setup with public ip to allow port forwarding - router

In my country, our internet is accessed, in most homes, through the phone cables.
So you normally have a simple modem/router that accepts a dsl-cable.
Now, I have a project where I need to put an application online.
For this, I have bought a TP-Link TL-R407t+ and I have a Technicolor modem/router with wifi.
The setup now goes like this: phone outlet --> technicolor --> TP-Link.
This gives me wifi from the technicolor and the internet through the tp-link works through an ethernet too.
The TP-Link, I have set up for port forwarding. Yet, what remains is that the TP-Link has a private ip. I am lost in figuring out how I get it to use the public IP, so that once I write xx.xx.xx.xx:8080 or whatever into a browser, my app shows up.
So my question is, how do I setup my routers, or add stuff, to allow the port forwarding to work.

Related

Photon Connection from IPv4 clients to IPv6-only photon server

Just as the title says,
Not all ISP in our country support IPv6 yet, some does, some doesnt,
I dont want to create a situation where players can only play our game only if
he/she has a certain "IPv6 enabled" ISP. That won't be great. The ISP I used support IPv6.
My server(pc) is set behind a series of NAT, (I dun know the architecture but port-forwarding from the router is not enough, it has its own "local" ipv4-address from its "parent"(I don't know the ip-address of the parent)). Also I have contacted them, to give me a public IPv4 but unfortunately, it didn't go well as planned.
At the start, I tried to use IPv4 address given by "whatismyip.com", but well it gives the IP address of my ISP, not my router or my PC.
And then, there is this, I can access the server via IPv6 connections. But can't via IPv4. so how can I establish the connection between the two? How can I solve it?
(Please feel free to ask about any more information that is needed, I just recently started to learn networking so they are lots of things i might be wrong about, sorry in advance)
Thanks in advance! UwU

Is portforwarding necessary for website without a domain

I am quite ignorant to the nitty gritty of networking. I am about to create a program for the raspberry pi that tells me the humidity of the room, then proceeds to put it on a web page.
I know how to set this up for my network, but if i wanted to give it to some random person then a problem presents itself.
My question is, it it possible to host a website without a domain, and without port forwarding. And connect to it by http://publiciphere:porthere
If your raspberry pi is hosted on a private network you would need to configure your router to forward requests on a given port (e.g. 80) to your internal ip for the pi.

iphone app can't see internal network

I'm working on an Enterprise app that communicates with our company servers. I have full two-way communication between the phone and the server through 3G/4G, and it works from my home wifi, but using the wifi at the office where it is connected to the company network the app doesn't see the server that way.
The app is set to look for our external IP address, and the port is open to the server. But I guess the external IP address is not 'visible' from within the network. When I plug in the internal IP address of the server, it goes through just fine.
For the vast number of our users, that would not be a problem. Most of our users (employees) work in the field or in other offices. But for users inside our network, this arrangement is useless unless the user turned off his wifi. But that's not a professional way to do it.
I need to know if there's a way for my app to either use 3G/4G exclusively, or to discover the SSID of the wifi and decide which IP address to use. I'm guessing that the answers to both of these will be, "you can't do that," But I thought I'd ask anyway.
Thanks!
You could have it attempt the internal IP, and fall back to the external IP if it can't connect. A better solution might be to have an internal DNS server that serves the internal IP to in-network devices, though.
Well, I discovered this code is exactly what I need. It gives me the SSID in string form, and I can compare the SSID string with a string of our wifi's SSID, and if it matches then the app uses the internal IP address. And if it doesn't match, it will connect to the external IP address. So far it works perfectly!
Followup: ceejayoz, I don't know if your second suggestion is the same as what our IT guy did, but he created a domain name that will resolve to the server whether it's internal or external. That seems to be the best way to go. So even though I had a workable answer, the URL works better with less code.

Possible to send data between two iOS devices?

I've read tons of questions about this all over the web, and can't seem to find a solid answer. If I have an iPhone that's running on cellular data and another iOS device on wifi (in two separate locations), is it possible for them to send data to each other directly without sending it first to a web server, then retrieving it? Are the only options sending and receiving from a server/Apple's iCloud? What if I knew the devices' ip addresses? Note that the iPhone has WiFi disabled.
I'm not looking to put this in the app store, it is for personal use. I know NSNotificationCenter isn't an option.
Using the gamekit framework you can send data between two iOS devices. It is easy to implement. Other than that I don't think there is any other way to send data between two iOS devices.
Actually, it IS possible. You may want to google for something called "UDP hole punching" or "TCP hole punching".
The main approach in short: Assuming you got something like a relay server, that is some server in the internet that is publicly addressable from every private LAN that is connected to the www. No you have your two clients A and B in (different) private LANs, with some Network address translation (NAT) going on, that want to establish a peer to peer connection.
First of all both will tell the server their IP address and the port they have in their own LAN. In the UDP or TCP packet, the server will find the public address and port of the device (or the NAT (router)). So the server knows the private and the public IP address as well as the ports.
If now A wants to communicate with B, it asks the server for help. The server will send a message to B that A wants to communicate with her telling her A's public and private IP and port. A gets back B's public and private information and port.
Now here is where the magic happens. Both clients now send packets out to establish a connection simultaneously to the private and public addresses of the other party and thus punching a whole in their NATs such that incoming connections will not be blocked. Even if one party's connection establishing packets will arrive before this whole is created, the other's packets will get through to such that a connection can be created.
Beware of some NATs that scan the data for IP addresses and translate them as well, but if you encrypt your data or change the appearance of the address (complement, ...) you will be fine.
Now the master question, how can the server communicate with one of the clients without an active connection. Well in this case you can use "connection reversal" and apple's "push notifications". Use the "push notifications" (pn) to tell a client behind a NAT that there is something of interest going on and that it should contact the server. Once it has done that the connection is active and can be used in the previous described fashion.
I hope this helps some people that get to this problem although the post is quite old!
You can only use direct IP address communications if the IP address are publicly reachable IP addresses accessible over the internet, and they are static (enough) so that they are not changing on you regularly as devices get assigned to addresses dynamically. In many (most) cases, that won't be true because your devices will be assigned their IP address dynamically and those addresses are frequently going to be self-assigned IP addresses that aren't publicly addressable.
As others have commented, using Apple-provided mechanisms like iCloud are probably the easiest options. If that's not something you'd like to entertain, there are probably ways to make use of a dynamic DNS service like DynDNS to manage the actual IP addresses of your devices. With something like that you might be able to use a direct IP connection between devices based on a named DNS lookup. You'd probably have to jump through some hoops to make that happen though and I'm not sure you'd want to go to that extent.
I think that Bluetooth would be a good option for you

iPhone - Peer to Peer connection over the internet

I am building an app that uses a async socket connection with a web server.
For sending large amounts of data I would like to connect two iPhones into a Peer to Peer connection using an async socket. I am more familiar with GCDAsyncSocket than to the iOS SDK socket API.
I have done something similar, but only within a local network were I would user NSNetService to publish a presence and get the addresses needed from the p2p connection.
Can you give me a hint on how to connect two iPhone over the internet using a p2p socket connection?
I do not know much about NSNetService but it seems that it only works in a local network. If you want to establish a p2p connection from an iphone to another you will always have the problem of several NATs (Network address translators) in your route. How to find the address and route to the peer? And how to get trough all the firewalls and NATs?
I am working on an app that needs to deal with the same problem and I have answered a similar question before which I will cite here:
Actually, it IS possible. You may want to google for something called
"UDP hole punching" or "TCP hole punching".
The main approach in short: Assuming you got something like a relay
server, that is some server in the internet that is publicly
addressable from every private LAN that is connected to the www. No
you have your two clients A and B in (different) private LANs, with
some Network address translation (NAT) going on, that want to
establish a peer to peer connection.
First of all both will tell the server their IP address and the port
they have in their own LAN. In the UDP or TCP packet, the server will
find the public address and port of the device (or the NAT (router)).
So the server knows the private and the public IP address as well as
the ports.
If now A wants to communicate with B, it asks the server for help. The
server will send a message to B that A wants to communicate with her
telling her A's public and private IP and port. A gets back B's public
and private information and port.
Now here is where the magic happens. Both clients now send packets out
to establish a connection simultaneously to the private and public
addresses of the other party and thus punching a whole in their NATs
such that incoming connections will not be blocked. Even if one
party's connection establishing packets will arrive before this whole
is created, the other's packets will get through to such that a
connection can be created.
Beware of some NATs that scan the data for IP addresses and translate
them as well, but if you encrypt your data or change the appearance of
the address (complement, ...) you will be fine.
Now the master question, how can the server communicate with one of
the clients without an active connection. Well in this case you can
use "connection reversal" and apple's "push notifications". Use the
"push notifications" (pn) to tell a client behind a NAT that there is
something of interest going on and that it should contact the server.
Once it has done that the connection is active and can be used in the
previous described fashion.
I hope this helps some people that get to this problem although the
post is quite old!
Now if you find this solution helpful and you try to implement it, please tell me if you are successful in getting the public ip and port of the server-client connection on the server side. You can also answer my question about this on stackoverflow.
Please be specific, u may use GCDAsyncSocket to connect 2 phones, u may use sample code from Github.