On a Windows 2016 Server, I need to set a custom route, so that connections to a specific destination ip address always use a specific source ip. But while the
route add command allows me to specify the interface, it does not allow me to specify a source IP.
The server has one network interface with multiple IP addresses, e.g. both
10.0.0.20 are bound to this network interface, and the server is reachable by either IP:
c:>ipconfig Ethernet adapter myAdapter: IPv4 Address. . . . . : 10.0.0.10 Subnet Mask . . . . . : 255.255.255.0 IPv4 Address. . . . . : 10.0.0.20 Subnet Mask . . . . . : 255.255.255.0 Default Gateway . . . : 10.0.0.1
By default, all outgoing connections use
10.0.0.10 as the source IP.
I need a route, so that all connections to one specific remote address (
10.123.123.123) always come from the second local ip (
10.0.0.20), because the device at
10.123.123.123 is configured to only accept connections from
10.0.0.20, not from
c:>telnet 10.123.123.123 111 This tcp connection should use 10.0.0.20 as the origin IP
I can add a route with
route ADD 10.123.123.123 MASK 255.255.255.255 10.0.0.1 METRIC 1 IF 1
However this does not change the source IP address
10.0.0.20. Outgoing connections still originate from the IP
How can I specify which IP address the route should use, when both IPs have the same interface number?
Only connections to the IP
10.123.123.123 should be affected by this route.
All other connections should continue to use the origin IP
Since this is a complicated legacy system mess, I am looking for a solution with minimal risk of affecting other connections, and without changes to existing software.
Therefore I would prefer not to change the global metrics for this interface, or split up the interfaces, if at all possible. A specific route affecting only ip
10.123.123.123 would be ideal.