Time Ago I worked in a service request that our customer reported that their outbound IP has changed without any notice. Working on this issue I have found an interested situation to identify IP of the load balancer of a virtual machine running on Azure.
I created two virtual machines using the same VNet.
The first machine has the Public IP:
The second machine has not a Public IP:
When I try to connect to my Azure SQL Database server xxxx.database.windows.net I have found the following scenarios:
- The machine without public IP is using an IP 126.96.36.199. Searching the outbound connection for Virtual Machines I have found the following URL that explains this IP is coming from : https://docs.microsoft.com/en-us/azure/load-balancer/load-balancer-outbound-connections?toc=%2fazure%2fvirtual-network%2ftoc.json
- Running the nslookup myip.opendns.com resolver1.opendns.com I obtained the same IP
- So, this IP from the Load Balancer may be changed without any notice.