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Chris_103447's avatar
Chris_103447
Icon for Altocumulus rankAltocumulus
Jun 23, 2015

Issues with Exchange 2013 load balancing through LTM (v11.6)

I have a support case open for this as well, but since no one has truly engaged in spite of a Sev1 classification, I'm hoping someone in the community can help. Thank you ahead of time.   We have ...
application delivery
exchange 2013
LTM
microsoft
Chris_103447's avatar
Chris_103447
Icon for Altocumulus rankAltocumulus
Jul 20, 2015

The issue here was a conflict between Auto Last Hop and our virtual environment. For some reason, traffic through our QLogic converged network adapters would carry the host MAC rather than the virtual NIC MAC, and Auto Last Hop would try to return traffic to the host rather than the guest.

 

We suspect that this may be related to the QLogic CNAs, as they have exhibited strange behavior in other situations and are renowned for bad driver issues (on both Hyper-V and vSphere). For now, we've worked around it by disabling Auto Last Hop globally. We aren't losing anything by that action compared to our prior setup on Kemp VLMs, which didn't have an Auto Last Hop feature.

 

Thanks,

 

Chris