I'm load testing some web services hosted on IIS7. The web services make network calls to underlying services in response to client requests. The client requests are simple HTTP requests but the requests that emanate from the web service layer start with a ping request (ICMP echo). After almost 6-7 days I have noticed multiple ping request failures and when I monitored the traffic on Wireshark I was able to see that these co-related to multiple ICMP Destination unreachable errors. Intermittently some successful ICMP echo are also present.
Can anyone suggest a good starting point for my investigation? The frequency of hits on the server are ~200 http requests/sec.