I've setup a medical software on a LAN which uses the client/server model.
The server has a UPS and I wanted to know if every client PC needs one too.
What could happen if a power outage occurs while clients are writing to the server?
All of the PCs including the server are running on Ubuntu 18.04.
Thanks,
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I'm really looking for advice and a starting point more than anything. So I'll try my best to explain my end goals and the challenge. I want to set up a local WiFi connection (P2P) between a Rpi3 (or any embedded system really, running linux) and a laptop. The Pi should be the server and laptop the client. The raspberry PI is going to be reading samples over USB from an SDR. I want the laptop to be able to connect to the network the pi throws up, and be able open a browser and view the results. I'm guessing what i need to read up on is ports/sockets and web programming in general. The cheepy IoT sensors and light bulbs seem to be able to do this (opening network and forwarding data) relatively easily but i cannot find any information online to aid in my quest. All the Best and thanks in advance.
Since the embedded system will be running Linux, you can do something along the following lines:
setup the wifi as an Access Point (example). Also setup DHCP Server (example), so the wifi will assign an IP address to connecting laptop.
Install a webserver (e.g. Apache).
Create the webpage/ web application you need to "serve" the data. Install this into Apache.
Ask follow-up questions if you like.
We have dongle server what allow us to use them in differen VM servers (we use VMWare).
We connected some dongles to VM Windows 2012 server. If we use VWare terminal to connetc to server we can see all the dongles and our software can work with them with no problems.
But if we connecting to server via RDP all dongles stop working.
Even if we turn off smart card sharing in RDP options.
As stated here this is default behaviour of Smart Card service with RDP.
But we dont want crash our app behaviour then someone want to do some some maintainance on this server.
Is where a way to handle this rather than turning RDP connection off?
I have a scenario where I have a Windows VM in windows Azure that needs to connect to an external customer network (and connect to a database that is not in Azure).
This traffic is uni-directional in that it is only my VM that needs to connect to the customer's databases and not the other way around. Site to site is managed on Azure, which I cannot really test locally.
Conceptually, connecting to the customer's network via a point-to-site VPN seems more suitable (by creating the VPN connection in Windows itself via the network config).
The customer prefers site-to-site even though they don't need to connect to my VM. Am I missing something?
In point-to-site, you have to connect to the network you want to access manually. Usually, if you log-off or restart the workstation it loses connection, and you have to reconnect every time. It's common to use this type of VPN when we are working remotely, and we need to access our company assets. The channel is bi-directional, but it's 1-to-many.
Site-to-site is used when you want to connect two networks and keep the communication up all the time. It's also bi-directional, but it's many-to-many and stays up no matter if your server/workstation is running or not because the connection is established through a network gateway and not from the computer operating system.
In Azure, the Virtual Network Gateway is the platform providing both functionalities. You can configure site-to-site to connect to your customer network. If this network is not running in Azure, they usually have an appliance to establish dedicated tunnels. As long as it supports IPsec IKE, you are good to go.
If you are using the VM in Azure as a workstation, then point-to-site may be enough, but if your application needs to get data from the customer database automatically with or without someone logged in the VM, then site-to-site is a better approach.
A better explanation can be found here
I have set up a Win XP machine at work that we use as our server, to allow RDP connections. This allows all our staff to access the server from home when needed. As it is not a server OS, we are missing many of the terminal services features a regular server would have. The machine only allows one RDP session at a time (which is a minor inconvenience, but not a big deal).
What is bothersome, is that no one can tell if the server is currently being used in an RDP session, and we all keep booting each other off. Every solution I have found online assumes the remote computer is a Server OS or on a local network/domain. Our staff's home computers are not connected to the office network and we have no domain set up at the office.
Is there any way to tell if the server is in an RDP session before remoting onto the server from home? Ideally we would be able to detect which home computer is accessing the server. But if that is not possible, it would be extremely helpful to at least know that an RDP session is running.
We were previously using logmein, which could tell us if the remote computer keyboard and mouse were active and allow a chat with the user currently remoted on/physically on the machine. This was extremely convenient, but involves logging onto the logmein website and going through a semi-lengthy process of connecting. It is also much slower and resolution is much worse than RDP. Not super convenient for regular daily use.
This post deals with the same issue
https://superuser.com/questions/313390/ways-to-check-if-user-is-active-on-remote-machine-before-rdping
but the accepted response is to use qwinsta on cmd, which I believe is only available on server OS's. Other responses include using psexec (I've tried using psloggedon.exe, but this appears to only work for users on the same domain). Another suggests using the wmic.exe command, but when I try that I get the error: The RPC Server is unavailable (I think this also needs to be run on the same domain).
So basically - is there any way to check for active rdp sessions on a Win XP machine from a remote computer not on the local network/domain?
I'm open to outside-the-box solutions like writing a simple app to run on the xp server and tell remote machines what IP is connected in an RDP session.
Going on Harry Johnston's suggestion, I wrote an app which finds who is connected to the xp machine on port 3389, and relays that information by udp to receiving apps. Now we can check if someone is connected and who it is before unwittingly booting them off. Thanks Harry!
I have a program consisting of a server and a client processes. Both run on Windows systems - Windows 2000 or later versions. The two processes can run on the same machine or on two different machines.
How can the client determine if it is run on the same machine as the server? If the server is not running the client can't work anyway and doesn't care where the server possibly is - so this case is out of the question. I've heard that each Windows machine has an UUID - can I obtain it and use for that purpose?
Windows networking requires computer names to be unique, so calling the GetComputerName api and having the client and server swap names (and compare the received name to the name they see) should suffice. If the client and server can start up independently of one another then you'll need some sort of protocol for this process. It seems logical for the client to initiate the exchange, and the server to only send its name when it has received a name from a client. The client can then abort the connection if it sees the same name.
I believe most virtual machine systems will allow the virtual machine to have its own name, so it should still be possible for you to test on virtual machines. However I don't have extensive experience of all the virtualisation technologies out there, so can't say for sure.
Previous question about generating a unique machine id that might help.
Link to previous answer which mentions MachineGUID
It is straightforward to add an API to the server that reports its machine name. The environment variable is COMPUTERNAME. The client could check that, right?
Do you need to deal with any of these cases?
The client is running, but the server is not responding, and you want to know whether the unresponsive server is on a remote machine.
The client and the server are running in two distinct virtual machines on the same host machine, and you want to report that as "running on the same machine."
The client is running in a virtual machine hosted by the same machine as the server is running on, and you want to report that as "running on the same machine."
The client and the server are running on uncoordinated networks and both might have been assigned the same name.
The server is possibly hostile, and will attempt to deceive the client.
The network card will have a unique MAC. If both server and client report the same MAC then they are using the same network card. If both client and server are running in different virtual machines but using the same network card, do you consider them running on the same machine or different machines?
how about trying to establish a loopback tcp connection? or maybe checking for some lock file created by the server in a predefined folder...
I don't know exactly how, but there's for sure something equivalent in Win32 to the /proc filesystem in Unix (I think there are free replacements for the windows taskmanager, maybe you could look at their sources) where you could search for your server process.