For those who have plans upgrading their environment from vSphere 6.0 to 6.5 Update 1, I would suggest postponing this until VMware resolves issue documented in KB 2151749.

Hosts will be affected if they equipped with 10 Gbps NICs.

The only workaround that the vendor has at the moment is to downgrade ESXi to 6.0 Update 2.

17/10/2017 – Update 1: According to VMware GSS, this issue is going to be “resolved in ESXi 6.5 Patch 02, which is schedule to release this month (The release date may change without notice).” Please refer to the SR #17599111410 when contacting GSS for more information.

08/02/2018 – Update 2: This issue is resolved in VMware ESXi 6.5 P02 (ESXi-6.5.0-20171204001-standard).