Azure – How to run a client-server program on two virtual machines at different locations in Azure

azureazure-networkingclient-serverconnection

I created two virtual machines in Azure. One of them is in Australia South and the other is in Central India. I ran client program in one machine and server program in other machine. There are not able to connect to each other. After a little google search, I created Network Security Group in both VMs and added the following inbound and outbound rule.

Source – Any

Destination – Any

Service – Custom (Any/32000-32200)

Action – Allow

I am connecting to ports in between 32000-32200 in my program, but still the machines are not connecting to each other. I am using Ubuntu Server 16.04 and classic deployment model. I kindly request you to help me out..
I am attaching screenshots of my network security group and output of netstat command.

Network Security Group

netstat

Best Answer

Two Vnets in different regions's communication is just like on-premise to Azure. As Sam said, there is no directly connectivity between the two VNet. According to your description, you use Public IP for VM's communication. I suggest you could check as the following ways:

1.Please use you could connect port 32000-32200 from one Azure VM to another VM, you could use telnet to test.

2.Check the result netstat -ant|grep 32000(Linux), please ensure your port is listening on tcp and 0.0.0.0.

3.Open ports on Azure NSG, according to your said, you have added it. Please pay attention to Azure NSG could be associated to VM's NIC or Vnet's subnet.

4.Check your VMs's firewall. If your VM's are Windows OS, you need open ports on Windows Firewall(Inbound rules).

Update:

For a classic VM, you should open ports on Endpoint, more information please refer to this link.

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Azure virtual machines in the same network can’t see each other

If by "don't seem to recognize each other" you mean you can't send and receive ICMP pings that's because ICMP is disabled on Azure VMs.

Try opening a TCP socket on the desired port running the service to which you want to verify connectivity instead:

PS C:\Windows\system32> New-Object Net.Sockets.TcpClient "192.168.10.10", 8043


Client              : System.Net.Sockets.Socket
Available           : 0
Connected           : True
ExclusiveAddressUse : False
ReceiveBufferSize   : 65536
SendBufferSize      : 65536
ReceiveTimeout      : 0
SendTimeout         : 0
LingerState         : System.Net.Sockets.LingerOption

NoDelay             : False

Azure – the difference between an Azure network security group and a VNET

NSG's could, I suppose have been implemented as part of the vNet, but actually the current approach provides more flexibility, especially if you are using templates to deploy.

vNets are your containers that provide communication between between VM's and a boundary between your environment and the outside world. Inside vNets you will create subnets to organise your network as you like and configure routing rule to define how traffic flows (if you don't like the defaults). vNets also provide the functionality to hook into things like VPN's and Express route.

NSG's are your firewalls that determine what traffic is allowed through. The important thing to note is that NSG's can be applied to individual machines, or to subnets. This distinction means you can apply an NSG to subnet and it can control what traffic is allowed in both from teh outside world, but also from other subnets on your network. Alternatively you can define it at the VM/NIC level and lock things down just for that VM.

Best Answer

Related Solutions

Azure virtual machines in the same network can’t see each other

Azure – the difference between an Azure network security group and a VNET

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