I need to access about 15 devices remotely with a software in a single server.
All these devices are connected to the internet through modems and I can access them, privided I have the modem IP. But most of these modems have dynamic IPs that usually changes more than once a week for various reasons.
I tried using dynamic DNS, but it doesn't work because the software accepts only IPs in the format XXX.XXX.XXX.XXX in its configuration.
Is it possible to configure a DNS server (or any other tool) to point to one of my dynamic DNS when asked for a specific IP address in my local network? I was going to try it but my Windows server fails to install the DNS server role, so I want to know if I should even bother solving this other problem.
In other words I want to do this: local IP -> global name address -> global IP address
Example: 192.168.1.100 -> dynamic.name.com -> 200.100.10.27
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I have a local network with several PCs and specialized controllers on it. These specialized controllers must be configured with static IP addresses and do not have DHCP capabilities.
I was asked to put together a list of the device hostnames and IP addresses. It's easy to figure out the IP address of each device, however, I'm struggling to find out the host name for these specialized controllers. If it were a Windows PC, I would simply navigate some menus to find the host name.
I'm confused about how the host name is configured for network devices in general. For Windows PCs, it seems like the PC itself determines its own host name. When it joins a network, it simply broadcasts its host name to a DNS server and the DNS server remembers it. For devices that are not DHCP, it seems like I would need to manually go to a DNS server and enter the host name for the specific IP address.
So what exaclty determines the host name? The device itself or a network admin?
This more of networking question and belongs to ServerFault - you will get your answer faster there.
If it were a Windows PC, I would simply navigate some menus to find
the host name.
What kind of system is there if there is no Windows? Linux, *BSD, AIX, other? I'll answer for Linux for now.
So what exactly determines the host name? The device itself or a
network admin?
This depends on your configuration in Linux check - /etc/nsswitch.conf
e.g.
hosts: files dns
Which defines that the hostname will be defined by /etc/hosts and if it is not found there it will check DNS next.
If hosts file, the local resolution, contains the pair ip <-> name it is used. If the DNS takes precedence and it contains the pair it is taken from there. As shown above, it can contain both at once in defined order, then the resolution is done in that order.
By the way, DHCP server can give you static IP addresses based on your MAC address so your controllers will have always the same IP address, if same network card is used. It is way easier to manage than configure all servers manually.
I set up my pi to broadcast it's own "wifi" and I have an Apache server running on it.
I used this tutorial https://learn.adafruit.com/setting-up-a-raspberry-pi-as-a-wifi-access-point
I can currently connect to the network that the pi is broadcasting and go to the ip of the server on my phone and it brings up the webpage, but I want to be able to type in "mydomain.net" and have it bring me to the webpage. Can anyone help me with this or suggest anything?
I want anyone that wants to connect to this local wifi (not worldwide) to be able to enter the website so changing everyone's host file is not going to happen.
you can modify /etc/hosts file on your local machine to point the custom domain name to the IP address of the environment you want to test. The /etc/hosts file contains a mapping of IP addresses to URLs.
Your browser uses entries in the /etc/hosts file to override the IP-address-to-URL mapping returned by a DNS server.
This is only useful for testing DNS (domain name system) changes and the SSL configuration before making a website live.
I have developed an IOT module which can connect to the Wi-Fi and send data to the internet, the module can send data (string) to specific IP address on the specific port.
The internet server should store that information to the data base and display that information to the user via HTTP (web page).
When I set the port to the 9081 (any random number) and my local computer IP address as IP address that module should send data to, I can see data on my local computer terminal.
My question is that how can I send that data to the internet?
What I have in mind is that I can purchase domain name, host and develop a web site (HTTP) which by default listen to port 80. The service provider only give me a basic services such as HTTP, HTTPS and FTP which make it possible to upload website and I don’t have access to other protocols and ports.
Should I purchase virtual private server or I should use any specific cloud services or the module can send data to the server on port 80 without getting conflict with web pages and web contents?
Please give me some suggestion.
I did something similar with an IoT module. There are two options that I also considered. Before we describe, there is no need to buy a domain name. You can comfortably use the IP address to connect to. If you have some spare cash go for it.
Send everything to the web server on your local computer. To have access to the local computer you must enable port 80 to be accessible over the internet. You do this on a router. This is called port forwarding. You setup a rule such that all the requests made to your IP address on port 80 should be redirected to your local computer on whatever port the web server is listening to. This is the cheapest method available. Also, there is an important limitation: you're local computer needs to be switched on all the time if you want to access the data.
Buy a droplet (virtual private server). The workflow is the same as 1, but you don't need to port forwarding anything. These are usually setup and ready to use. However, this is usually expensive. Most of these providers offer pay-as-you-go services (e.g., Digital Ocean is the one that I used). There are other providers which offer free but limited versions. These are usually developer trial versions. If you go over a number of transactions, or space, you will have to pay (have a look at Parse).
I created an AMP web application that was originally going to be served from a traditional 3rd party host.
As we finished up, the client decided to host it internally, on a server in their office network. The application is only meant to be available to staff members, but those staff members will often be off-site. I had no involvement in setting up their network, which uses at least one server running windows server 2003. The client machines I saw were XP.
I set up Apache, MySQL and PHP on the server 2003 machine, and installed the application. The application is built on the CodeIgniter framework, so I set the base_url to the internal IP (192.168...), and we tested from within the network. Everything worked fine.
Next, we asked their network guy to open port 80 for apache. I set the base_url to the external IP, and tested from my home (using the external IP as the web address), and it works fine.
However, when attempting to access the application using the external IP from within the network, they're unable to connect. I can reset the base_url to the network IP, and they can access it using the network IP, but then it the application fails when connecting externally (since the base_url, used throughout the application, is pointing to the internal IP).
It suppose I could let CodeIgniter determine the base_url (by leaving the variable as an empty string), but would rather figure out why the external IP fails in-network, and try to correct that.
The server we're using is not dedicated to the AMP stack (in fact, it has at least one other application broadcasting to the internet that must have been using IIS, as well as an FTP server used for office scanners), so I suppose there might be some conflicts there.
I know very little about windows networking. A quick search suggested this might be because of NAT, but didn't offer a work-around.
Their network guy has no suggestions, and said that everything should be fine.
Is it possible to have users inside the network access the Apache server using the external IP, and if so, what needs to happen to enable that?
TYIA
Your client's NAT router is configured to forward packets arriving on its external interface for its external IP with port 80 to the internal machine, port 80, after re-writing the source and destination IP addresses in the packets.
From within the network, attempts to connect to the external IP address will be routed to the default route on the machines, the router's internal interface. This interface is not configured to forward packets back into the network.
Configure the application to listen on all IP addresses. Make sure that the server knows that the clients know it under several hostnames -- the internal IP address and the external IP address.
You might be able to re-write the NAT firewall rules on the router to perform the port forwarding for the internal interface as well, but off-the-shell equipment common in homes and small businesses do not make this task easy. More expensive gear (or home-built *BSD/Linux router machines) can do this without much effort, but it would needlessly add traffic to the router.
This isn't Apache related, nor is it CI related. It's often impossible to reach the external IP address from within the network.
Frankly, I don't know exactly why that is. I do know that it's related to how NAT (Network Address Translation) works or at least how it's implemented.
For a detailed overview of why this is, you should ask this question on serverfault. If you're simply a programmer who has to deal with it, accept that NAT usually works only from inside to outside and outside to inside, but not inside to inside.
You already mentioned one of the solutions in your question - don't use base_url. You could also simply run the server on an external IP address (not your company IP, but let's say a datacenter or something).
In order to notify all computers within the same LAN about my existence, I want to broadcast my hostname and IP address.
How do I go about doing so without sending them as a string?
Avik, this is what DNS is meant to be used for. While "regular" DNS is meant to hold names and IP addresses for each machine (statically configured), there is a dynamic DNS protocol which allows machines to update their DNS entries in real time.
This sort of capability is used in some of the office environments for my clients where printers on a machine are shared but the machines they're attached to use DHCP (meaning their IP address can change).
See here and here for details and the Windows implementation with DHCP.
Lets call your machine that wants to advertise itself the SERVER and all the machines that can use it, the CLIENTS.
Of course, dynamic DNS only notifies DNS itself of the name/IP mapping and is useful if the CLIENTS are already aware of your SERVER so they can get the IP address from DNS. If you have no way for CLIENTS to discover that your SERVER has just been added, you'll still need to broadcast a packet occasionally indicating that your SERVER exists (this will only need the SERVER name since CLIENTS will use DNS to get the IP address).
This broadcast packet should be picked up by all CLIENTS and kept in a local table. If the communications from a CLIENT to your SERVER fails, the local table entry for your SERVER should be removed (it'll be re-added when your SERVER broadcasts again).
Basically re-inventing NetBIOS or ZeroConf, as popular with small embedded devices for discovery by a Windows or OS X based installer or setup utility.
You can try to use UPnP Discovery.