Hi, I am running VMware ESX Server 3i Version 3.5.0 and accessing this server using VMware Infrastructure Client Version 2.5.0 on a Windows XP SP3 machine. I have enabled the Microsoft TCP/IP version 6 stack and assigned an IPv6 address (using the netsh command) to the network adapter. The guest OS'es running on ESX Server (includes Win7, W2K8, WinXP) also have IPv6 addresses enabled on their adapters. The adapters are configured to be in VM Network (Bridged mode) and hence have connectivity to the Internet. The VMs are able to ping each other using IPv6 addresses and are also able to ping a physical Win7 machine using IPv6 addresses. However, the Windows XP SP3 machine on which the Client is running is not able to ping any hosts running on ESX Server while the VMs are able to ping this host. Whenever I try to ping from WXP box I get the "Invalid source route specified." error. The WinXP machine is not able to ping the Win7 physical machine too (the same error as above is thrown). Can someone help me understand why I am receiving this error and what I need to do to resolve this error? Thanks, Vittal