Technical Note: Intermittent connection with two or more FortiGate VM on same hyper V server

[shlee]

Description

Traffic may experience intermittent issues when there are two or more FortiGate-VMs configured in the same physical Hyper V server with the following criteria:

1. Sharing the same virtual switch.
2. Virtual switch is configured as trunk and allowing all VLAN.

Diagram:

Solution

To resolve the issue, the following steps should be following on the hyper V server:

1. Upgrade driver and firmware of Emulex NIC to be driver version 10.2.531.0 and firmware version 10.2.477.10. Release note of this driver mention VMQ issues that caused virtual machine network connection problems have been resolved { Reference Link }.

2. Patch the Hyper-V hosts with KB3031598 { Reference Link }.