RTT and Hop Count

Sample code

The following sample code shows how to use GetRTTAndHopCount().

#include <stdio.h>

#include <winsock2.h>
#include <iphlpapi.h>

int
main()
{
 IPAddr ipaddr = inet_addr("127.0.0.1");
 ULONG hopCount = 0;
 ULONG maxHops = 64;
 ULONG rtt = 0;

 if (GetRTTAndHopCount(ipaddr, &hopCount, maxHops, &rtt) == TRUE) {
   printf("Hops: %ld\n", hopCount);
   printf("RTT:  %ld msec\n", rtt);
 } else {
	 printf("GetRTTAndHopCount failed : %d\n", GetLastError());
 }

 return 0;
}

Sample code output

The sample will output an message like the following.

The destination host in this sample is 127.0.0.1 (localhost). Therefore, the Hops is 1 in the sample result. The RTT value 0 is also because the sample destination is localhost. RTT is 0 because the round trip time to itself does not take any time.

Please note that, if you change the destination host to an other IP address, these values will change. The RTT and Hops will be a more higher value.

C:> a.exe
Hops: 1
RTT:  0