We have two Windows Server 2012 machines with Intel NetEffect NE020 RDMA NICs fitted. Previously we had SMB Direct working between these two machine - we just transferred files and SMB Direct was used automatically. However since then one of the machines has been upgraded to Windows Server 2012 r2 and we have made some changes to the network, and now SMB Direct is no longer working.

I've followed all of the setup steps in Jose Barreto's blog: http://blogs.technet.com/b/josebda/archive/2012/07/31/deploying-windows-server-2012-with-smb-direct-smb-over-rdma-and-the-intel-neteffect-ne020-card-using-iwarp-step-by-step.aspx.  I believe I have all of the correct firewall rules, but I've disabled the firewall on both machines to eliminate it. I've also cut out the switch and directly connected the two NICs, with a couple of different cables. None of these changes makes a difference. I've enabled various logs, all of the SMBDirect and SMBClient logs, including ObjectStateDiagnostic as suggested in Jose Barreto's blog, and none of them yields and obviously relevant messages.

Message Analyzer gives a hint at the problem - I can see the SMB Direct negotiate request leave the client, it's received by the server and the server sends a response with success status. However the client never sees the responses, and appears to time out after ~30s, issuing an NDK disconnect. In the interim the file transfer completes over ordinary SMB3.0. I've repeated this many times with the same result. Most of the time the r2 machine has been acting as the client, but it fails in the same way if I swap client and server.

One other quirk I noticed in Message Analyzer was that the SMB Direct sockets on the server have the same local and remote IP addresses, the IP address of the server. On the client the sockets look correct. I've no idea whether this is expected, a bug in Message Analyzer or maybe the root of the problem.

Any ideas on how this problem could be diagnosed further, or what the problem might be?

• Edited by Andrew Royal Monday, February 16, 2015 9:35 AM Wrong link

Hi,

In addition to the firewall rules ,mentioned in Jose Barreto's blog, have you checked other confingurations? Verify the network adapter\SMB configuration and verify the SMB conection. Update or reinstall the drivers for NetEffect NICs, it's recommended to manually look for the driver from its manufacture website.

Some more information and step-by step guide in the link below could also be helpful:

Improve Performance of a File Server with SMB Direct

https://technet.microsoft.com/en-us/library/jj134210.aspx

https://technet.microsoft.com/en-us/library/dn583822.aspx

Please also note that:

• You should not team RDMA-capable network adapters if you intend to use the RDMA capability of the network adapters. When teamed, the network adapters will not support RDMA.
• After at least one RDMA network connection is created, the TCP/IP connection used for the original protocol negotiation is no longer used. However, the TCP/IP connection is retained in case the RDMA network connections fail.