Verify hostswitch configuration on ESXi and KVM

Lets Verify hostswitch configuration on ESXi and KVM hypervisor hosts. Once the ESXi and the KVM are configured as a Transport node, the N-VDS (or previously called as hostswitch ) is created. The primary component involved in the transport nodes is the N-VDS. The N-VDS forwards traffic between components running on the transport nodes or between internal components and the physical network.

The nsx-vswitch module is invoked to create the N-VDS on the ESXi hosts, where as the OVS module is leveraged to implement the N-VDS on KVM. There will be VTEP interfaces on all the transport nodes (ESXi & KVM) for encapsulating and deencapsulating the packets.

So we have all the ESXi, KVM and NSX Edges are configured as a Transport Node. The hypervisor hosts and NSX Edges are part of the Overlay-TZ Transport Zone and the NSX Edges are also part of the VLAN-TZ Transport Zone. While configuring the Overlay-TZ, I have specified the Overlay Hostswitch and for VLAN-TZ, the hostswitch is VLAN-Host-switch

I have discussed about how to configure the Transport Node in my blog post at: http://www.virtualbrigade.com/how-to-create-a-transport-node-in-nsx-t/

Commands to verify hostswitch (N-VDS) configuration on ESXi:

When ESXi hosts are configured as a transport node, you can run the esxcfg-vswitch -l command as shown in the following screenshot to verify the N-VDS.

The N-VDS is a opaque switch, which means the vSphere administrator can only see the hostswitch but can not be managed from the vCenter Server or from the host.

esxcfg-vswitch -l

The Overlay is N-VDS switch that I have created on this host.

To list all the vmkernel interfaces on the esxi hosts, the administrator can run te esxcfg-vmknic-l command. This command will show you the VTEP interface details.

esxcfg-vmknic -l

The vmk10 is VTEP interface name that encapsulating and deencapsulating the GENEVE frame. When the packet is leaving the hypervisor hosts, the packets encapsulated with the GENEVE header and the destination host deencapsulate the packet and forwards it to a destination virtual machine.

Another important command is the esxcli system module list | grep nsx, this wil list all the nsx modules installed on the ESXi host. As I mentioned, the nsx-vswitch module is invoked to configure the hostswitch on the ESXi.

esxcli system module list | grep nsx

These three commands helps you find the hostswitch configuration via the CLI on the ESXi host.

Commands to verify hostswitch (N-VDS) configuration on KVM:

The KVM hypervisor hosts, leverages the OVS to implement the hostswitch.

To check the VTEP details, run the ifconfig -a command.

To verify the hostswitch configuration on KVM run the ovs-vsctl show command. This will show the hostswitch interface port details, ovs version, etc.