Windows 7 RC1 64-Bit joined to an Active Directory Domain (Dell Optiplex 745) Windows Server2003 32-Bit (HP DL360 G3) (BDC, Exchange, Symantec AV) Single Subnet Cisco Routing Windows 2003 Server DNS I can ping every server in my domain except for 1 server. The server is a Windows 2003 Server running Exchange 2003, it is also abackup domain controller it ofcourse has a Static IP. I am unable to ping the server nor am I able to connect to it's shares or connect an Outlook client to it from a client running Windows 7 RC1 64-Bit. The IP address resolves from the DNS server correctly. All other Windows 2003 servers respond from ping commands. Virtual Windows XP from within Windows 7 cannot ping that server either. All other workstations on the domain are Windows XP witha few Windows 2000 Pro straglers. I ran Wireshark Packet sniffer and I am not skilled enough to find any errors. I have tried an Alternate Intel server NIC in the workstation I have disabled IPv6 I have manually entered the DNS servers. I have pinged the IP of the server Server has been rebooted, and all updates (not including August 2009) have been applied. I have setup a second workstation with Windows 7 and have the same problem. None of the Above has worked thus far. If there are any other suggestions from the community please help. I am willing to give it a shot. As this is vital to getting Windows 7 adoption my company.

Is there anything in between 7 and the server? Try tracert command.tracert "ip address" or "Hostname" at command prompt.It works like ping, but if there is somthing in between the 7 and server that is not working, tracert (trace route) will show what device it passes though to get to the server. Tracrt will timeout out on the failed device. It will list it's ipaddress and hostname (if any).

There is nothing between the workstation running windows 7 and the server running Windows 2003 Server.Lets throw in another odd piece to the puzzle.approximately 1 out of 10 times the Ping will get a reply from the server on the first request. Which means at chance there is bidirectional communications.I am seeing the same anomaly with tracert.

I was able to solve this issue by determining the packets were getting stopped at the Router level. Cisco's Proxy Arp was stopping the packets. To resolve this issue I had to disable the proxy-arp on the inside interface of the router. This must have to do with Vista and Win7 addition of IPv6 packet structure. I hope this helps others out here that have the same issue.