Problem: Source IP address on Windows 7 / 2008 / Vista will always be the lowest numbered IP address on a NIC, no matter what order they are in your NIC configuration.
May cause issues with L2TP VPNs and some firewalls. IT Support Brisbane
NIC has multiple addresses:
Source address used for that interface will always be 10.1.1.1 because it is the lowest number, e.g. 10 vs 172.
Need to use netsh skipassource command to get correct functionality.
Show existing skipassource configuration:
netsh int ipv4 show ipaddresses level=verbose
When adding an address that you don’t want to be the source address:
netsh int ipv4 add address “Local Area Connection 3” 10.1.1.220 skipassource=true
May need these two KB hotfixes:
KB2386184 – Add skipassource functionality to Windows 2008 R2.
KB2554859 – Prevent skipassource flag from being cleared when you use the GUI.