Uma rápida pesquisa no Google retornou este usuário com a mesma pergunta:
O usuário fez uma captura do Wireshark e descobriu que, ao tentar efetuar ping no host, nenhuma consulta DNS estava sendo executada.
A explicação para esse comportamento foi:
I believe that nslookup opens a winsock connection on the DNS port and issues a query, whereas ping uses the DNS Client service. You could try and stop this service and see whether this makes a difference.
Some commands that will reinitialize various network states :
Reset WINSOCK entries to installation defaults :
netsh winsock reset catalog
Reset TCP/IP stack to installation defaults :netsh int ip reset reset.log
Flush DNS resolver cache :ipconfig /flushdns
Renew DNS client registration and refresh DHCP leases :ipconfig /registerdns
Flush routing table :route /f
(reboot required)