As an experiment, I'd like to get responses from a few different 8.8.8.8 servers (per anycast, multiple physical machines are grouped as one IP address, and I believe inspection of the request/response packet bits alone can not tell me which physical machine was actually used).
(Why the experiment? I imagine that there are brief moments when the responses are different due to network updating. And I imagine responses are often just intentionally different; e.g., 8.8.8.8 is a DNS server, so if I ask it for CNN's IP address, the response probably depends on whether I am in Europe or USA. Further, I could do this experiment with USA CNN's 151.101.1.67, instead of 8.8.8.8, to see if anycast still changes the responding machine when I source a "direct-151.101.1.67-labelled" packet in Europe...I am probably misunderstanding a lot of this, so would simply like to do some experiments.)
So, is there a way for me to modify the packet header/body to force an abnormal 8.8.8.8 server?
If not, it seems I would need multiple worldwide internet source injection points to make the requests (easily done with proxy or VPN, though I am hoping I could inject all packets from one point). I could then use tracert to deduce which 8.8.8.8 server responds. Or, is there a general direct/supported anycast method to distinguish which physical server responded?