Hello @Thayumanaswamy, Naresh ,
I understand that you are trying to connect to an Azure Virtual machine from a whitelisted IP address but it's not connecting since yesterday. And this was working fine earlier.
To connect to an Azure VM from Internet, you would need to allow the access from the NSG (Network Security Group) which can either be associated to the VM's NIC or the VM's subnet.
Network security group is used to filter inbound and outbound network traffic to and from Azure resources in an Azure virtual network.
Network security groups contain security rules that filter network traffic by IP address, port, and protocol. When a network security group is associated with a subnet, security rules are applied to resources deployed in that subnet.
Refer the below document which describes how to connect, via SSH, to a VM that has a public IP and also shows the exact NSG rule that you need to add:
https://learn.microsoft.com/en-us/azure/virtual-machines/linux-vm-connect?tabs=Linux
To learn more about NSG (Network Security Group), you can refer the below documents:
https://learn.microsoft.com/en-us/azure/virtual-network/network-security-groups-overview
https://learn.microsoft.com/en-us/azure/virtual-network/network-security-group-how-it-works
Additional troubleshooting documents that you may refer:
https://learn.microsoft.com/en-us/azure/virtual-network/troubleshoot-vm-connectivity
SSH related troubleshooting documents:
Kindly let us know if the above helps or you need further assistance on this issue.
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