I have a client that someone in the past setup two NICs on the server to be active on vSwitch0. vSwitch0 has load balancing set for Route based on originating virtual port. Switches are D-Link DGS-3120 series (their enterprise? grade switches). Switches are not stacked, but instead linked through Ethernet ports. Spanning Tree is disabled.
The performance of the guest servers is a little off - When I remotely connect to them for remote control, I deal with pauses up to 45 seconds and disconnects (using an RMM tool). I can connect to physical machines at this client site without issues.
End users report issues also - They lost connectivity to their financial application quite frequently during the day.
I moved one guest server over to a new VMware server with a single NIC and it's performing much nicer. The older server has plenty of compute and RAM, so I'm wondering if there are some MAC table issues on the physical switches due to the load balancing. I was concerned with Spanning Tree until I read https://kb.vmware.com/s/article/2047822 where it states:
Note: VMware vSwitches (Standard and Distributed) cannot form loops as there is no way to join two virtual switches together at layer 2 of the OSI layer. As such, no Spanning Tree Protocol functionality has been incorporated into the virtual switches.
I tried to display the config at the CLI but the switches were not giving it up. sh tech-support worked, dumped out to a log. A huge one. Looked through it and there is nothing Cisco/Dell/HP like with sections pertaining to each port configuration beyond:
MAC Base information : dev_num = 1, phy port = 19, medium = copper ==================================== State:Enable Speed:1000 Auto negotiation:Enable Duplex:FULL Duplex Mdix:fiber Flow control:Disable ==================================== Dump normal register vale: ...
I did verify there is no load balancing setup on the switches.
I'm kind of at a loss as to why there is a network I/O performance difference between servers with the one with a single connected NIC outperforming the one with two connected NICs.