Hi,We're currently evaluating server 2008. On our Windows 2003 Server builds we disable netbios and have done the same for 2008.We canconnect from a 2003 machine to a share on a 2008 machine without issue.However when trying to connect from a 2008 machine to a share on a 2003 server it brings up an error stating that the network connection cannot be found.If you enable netbios you can access the share okay.We are connecting using an ip address and there are no firewall rules in place. Any ideas why we have to enable netbios in order for shares to work.Thanks.

hi there,to ans the question. SMB protocol initially tries to establish connection usiing pot 139 or 445 which both fall back to tcp protocol later which means the redirector first check whether it can connect using 139 or 445 which eer port first listen to the request will start the connection you can still disable the port 139 and still have the network shares to talk on tcp port called direct hosting kb 204279 sainath Windows Driver Development

Thanks for that but I still do not know why this isn't working.The Windows 2003 server has netbios disabled so it will not respond to port 139. I have checked and the server is not listening on port 139 so it should be forced to use 445.If I try to connect from a Windows 2000/2003 server with netbios disabed it works fine but not from a 2008 server.Cheers.

hi there,i want to understand why do you want to block netbios ?, if your company is developing any applications,it wuld really be a problem in future / at present to disable netbios .so a best practice would be not to disable netbios .windows 2008 comes with 2 versions of SMB , SMB 1.0 whcih was used along with OS till windows xp, from windows vista and windows 2008 , the smb version it is using is 2.0 . But functionality wise when windows 2008 talks / communicates with windows xp / 2003 it still uses smb 1.0 which you can check through netmon/ ethreal captures.sainath Windows Driver Development

We have been disabling netbios on the vast majority of our builds since windows 2000.Our standard server build that disabled netbios since Windows Server 2000has been approved by MS Premier Support and has not caused us any issues. The only time we enable it is for Windows Clusters.There are also articles out there for hardening windows that include disabling netbios and ports 137,138,139.Our company will not be developing any applications that do require Netbios.Using SMB also means that our firewall team do not have to open upUDP port 137/138 ot TCP port 139.Thanks.