Given that the local machine has multiple interfaces and I connect to a remote machine, the OS will choose the interface through which the remote IP address is reachable. If my client doesn't explicitly bind to a specific IP and if the remote machine is reachable via more than one interface, is there a way to detect which local IP address will be used for the communication or is it purely random?
In Linux at least, it needs to have the route specified in the routing table, it is not random.
Related
For a machine with multiple IP addresses and has a hostname, how does the WMI remote query choose which IP address to connect to? I know that if we set the IP address of a machine in "hosts" file, the ping command will resolve to that IP address.
The reason I have this question is because one of the proprietary app
that I used had WMI query to get remote info, but it used different IP
to connect to the target machine than the one supplied in "hosts"
file.
I created two Qt apps: one client and one server.
I use them to send some data for handle a remote device.
If I am in localhost I haven't issues about them, but when i search to connect them by internet i don't know how to find correct Ip server to connect Socket Client.
How i can find this ip node?
Is there a class to find It?
you cannot find it automatically, if this is what you're asking about.
In real life you would deploy your server on some publicly accessible host, give it a domain name (important part as your host can change the IP address at any time) and connect the client via the DNS domain.
However if you're just playing around and you want to show to the world that your app works, specifying the IP address of the server in your client code would be perfectly fine (assuming you're running both the server and the client in the same network).
In that case, if you're running mac/linux run the command ifconfig (or just ip depending on the distribution). On Windows you can run the command ipconfig. Both windows and linux will give you a similar output resembling this:
Pay attention to the network adapters. There can potentially be many of them. You may have some emulated adapters if you have docker or VMWare, you may have the wireless adapters if you have a WiFi card, and then the ethernet adapters if your computer can connect to the the internet with an ethernet cable. Each of these adapters specifies a different IPv4 address. You want to pick the one that is connected to the same network as your client. So for instance if both your server machine and your client running machine are connected to the same wifi, you pick the address from the Wireless LAN adapter
I am facing a strange issue these days. I have a list of IP addresses which I want to connect to during the deployment using Jenkins. Now what is happening is, if I am deploying at one IP address (remote machine but in same location) in my local location server, I can successfully do that. But If I am trying to deploy to an IP address (remote machine in other country/region) It is throwing the error, saying
Error : Ip address XYZ is not reachable or is invalid.
Please be notified that I am able to get the response from the machine when I ping it using:
ping XYZ
But while trying to deploy on it using Jenkins, I am not.
Please let me know if there's any solution for this problem.
There isn't enough data points but you can look for these things
1. IP address, Check if all three machines are in same n/w (Jenkins Server, target and your machine)
You can check it with IP address of each machine
2. check Gateway set for Jenkins server
3. Best way if feasible is to ssh / rdp to your Jenkins server and try running your command manually that will give you
Local machine get loopback address(127.0.0.1), so it will be reachable or any local machine having IP address with same subnet mask thats called LAN.
When you are reaching out to remote machine, either it should be public IP address(visible to everyone in the world) or you must have connect to that Area-Network via VPN, this is called tunnelling to remote over the WAN (wide area network). Their(remote location) again, you will notice that all the IP address have same subnet mask as you have on the local machine.
So their could be be IP address duplication case in VPN scenario, where you are bale to ping but not able to reach. This is because, IP address is assigned to other machine but not you yours and ping responses are coming from that other machine. That means your machine is in failed to resolve ARP and in dormant state.
I'm having a static IP address, say:127.254.x.x
Is it possible to access my web application from some other place by just replacing the local host with my IP???
Also, what will I replace the local host with if Ithe server is on a wifi network.? I.e. The router assigns a different ip to my server(because of dhcp) other than my original static ip. In this case should it be
192.x.x.2:8090
Or
127.254.x.x
Any help is appreciated.
I'm having a static IP address, say:127.254.x.x Is it possible to access my web application from some other place by just replacing the local host with my IP???
Yes, provided you configure it correctly.
Normally, you have a broadband modem/router which talks to the outside world, and provides a NAT network range to your devices. So you have an external IP address (the one the modem/router uses to talk to the outside world), and probably several internal IP addresses (for your phone, your laptop, your other laptop, your Kindle, etc.).
So to access a web server on your internal network from the outside world, you have to do two things:
Configure your modem/router to "forward" traffic it receives on the desired port (port 80 for HTTP) to the server on your network. How you do this depends on your modem/router. Look for "port forwarding."
When trying to access the app from the outside world, use your external, not internal, IP address.
So for instance, if your external IP address is 222.111.222.12, and the IP address of the machine you're using as your web server is 127.154.0.23, then you tell your modem/router that whatever traffic it receives on port 80 it should forward to 127.154.0.23 (this configuration may be by IP address, or may be by the MAC address of the network card in your web server machine; it depends on the modem/router). Then to view your app from outside your network, you go to http://222.111.222.12 (or whatever name you assign that IP address to in DNS).
How can a Linux VM work out the IPaddress of the host node?
I need to connect to the IP address of the host node. I also need to know when it changes as it could be a dynamic IP. I need it to connect to a service there.
Is there some way to check this, irregardless of the type of VM, VMWare, Xen, Virtual Box?
It needs to be a Linux script, and should work regardless of the host operating system, whether Linux or Windows
My solution is to bridge a network adapter in the VM with one on the host, making it a dymanic IP address. As such it will always be on the subnet as the host adapter.
Next thing is to run an HTTP service on the host IP, that the VM will scan its network range on. The IP the service responds on will be the IP of the host. Having an IP service on the host is not ideal, but it is the best I can come up with.