Hi
We recently installed our second HPE BLC7000 bladeserver chassis. We have 6 ESXi G9 bladeserver that we want to balance between the two chassis. We have moved one of the servers to the new chassis and it works as it should. But when we use vMotion between the chassis we get a disrupt in the network traffic on the virtual machine that got moved, sometimes up to 3 minutes. VMotion of virtual servers within the same HPE BLC7000 chassis works without problems.
In the 2 HPE BLC7000 chassis we have 2 Virtual Connect FlexFabrics switches in each, they are connected to 2 Cisco Nexus 93180YC switches through port-channels that runs VPC.
When we use vMotion and moves a virtual server from an ESXi in one chassi to the other we see that it takes time before the MAC address of that server is updated on the correct port-channel in the Nexus switches. Our guess is that we have an ARP table that needs to be updated.
In VMware we have chosen "Yes" on the option "Notify switches" it was default as far as we know. And thus the ESXi host should send a gratuitous ARP or RARP to update the ARP data on the nearest switch. Though, could it be that the nearest switch in this case is the Virtual Connect FlexFabrics and that they dont update the Nexus switches?
We have read that there have been a old bug in Cisco Nexus switches regarding this and VPC. Our Nexus switches are running version 7.0(3)I5(1).
I know other companies that have a similar configuration as we have, eg. running HPE C7000 chassis with HPE Gen9 servers as ESXi hosts and Nexus switches and they dont have any issue with this.
Below is an example from one of the port-channels from the Nexus switch to the HPE BLC7000 chassi.
interface port-channel12
description BLC7000 VC1
switchport
switchport mode trunk
vpc 12
Thanks.
Olof
