We recently published a number of blogs (blog1, blog2) about network connectivity problems with our HP ProLiant Gen8 blade servers with Emulex adapters. Via the comment section on those blogs we saw we were not alone and several others were suffering from problems or even BSODs using other adapters than Emulex. Also Broadcom and Chelsio were reported as having issues. We can now also add Intel network adapters to the list (see afterthought at the end of this blog).
I just saw an interesting pointer by Didier van Hoye to a blog by Michael Rueefli aka Dr. MIRU from Switzerland, who suffered from BSODs after installing KB2887595 (November 2013 Update Rollup) on his Windows Server 2012 R2 Hyper-V clusters using Intel 82599 dual-port 10Gbps network adapters. Michael traced the BSOD back to the Mslbfoprovider which is the core driver for the inbox NIC teaming in Windows Server 2012 R2.
Previously I referred to as KB2887595 as as an update containing a stealth update (replacing Windows binaries without documentation). Evidently, this update has changed at least part of the lbfo network adapter teaming subsystem. Instead of fixing some of the network connectivity problems we had already encountered, it seems that in some cases, BSODs may occur on Windows Server 2012 R2 hosts with teamed Intel network adapters.
Like in our case with Emulex network adapters, the temporary workaround was to remove KB2887595 and reinstall the v2 version of KB2887595, then disable VMQ hardware offload. See Michael’s blog for instructions.
The Intel 82599 controller is also used by HP and is known as HP 560FLB Flexible LOM for HP Gen8 blade servers.
Afterthought: if so many different network adapters suffer from serious networking problems, it can be coincidence that all network vendors overlooked something in the testing process. On the other hand we could well face a bug in the NIC teaming subsystem of Windows Server 2012 R2. We will probably not find out before the end of the year.
Despite the trouble you may face, we at Hyper-V.nu wish you a quiet Christmas and a stable 2014!