How to setup a routing loop using route tables?

Question

I am attempting to setup a network loop using the route tables in Windows. The purpose of this setup is to test the impact that TTL Expired notifications have on a program.

I have the following machines:

• Computer1 - 10.10.120.50
• Computer2 - 10.10.120.60
• Computer3 - 10.10.120.70

I am using the following command to add an entry to the route tables:

route ADD 10.0.0.0 MASK 255.255.0.0 10.10.120.xx METRIC 3

To my understanding this should route any traffic to the 10.0.x.x subnet to 10.10.120.xx.

I have added the command above on Computer1 pointing it at Computer 2. I have added the command above on Computer2 pointing it at Computer 3. I have added the command above on Computer3 pointing it at Computer 2.

My thought is that this should cause a packet targeted at 10.0.0.10 to leave Computer1 (10.10.120.50) and go to Computer2 (10.10.120.60), which should then route the packet to Computer3 (10.10.120.70), and then it should be routed back to Computer2. It will then bounce between Computer2 and Computer3 until the TTL value expires.

The problem I'm having is that with these entries added to my route tables, if I run tracert 10.0.0.6 on Computer1, my tracert just shows stars/asterisks *, and it does not appear to route the packet as I hoped.

I have successfully simulated this test before, but must have tweaked something besides what I've outlined here because I can't recall what else needed to happen to make this work. Am I overlooking something? Also, if there is a better way to simulate a network loop to force a TTL Expired packet, I'm open to that as well.