I wanted to simulate the situation when the server doesn't respond, without changing much. A friend of mine suggested I use any of the unassigned IPs on our LAN. Exactly what I was looking for! The request timed-out and I was able to see how my application would act in this case. We may also add an entry in the hosts file to name this black-hole-server, so it can be used later as needed. The hosts file will also enable us to override the DNS look-up and route the requests to the black hole, in case the host name was hard-coded/fixed in a binary, and we don't want to/can't modify the code.