Browsed by
Tag: networking

NSX-V VTEP, MAC, ARP Tables content mapping

NSX-V VTEP, MAC, ARP Tables content mapping

It took me a while to figure out what information I see while displaying VTEP, MAC and ARP table on Controller Cluster in NSX. In documentation you can find what information are included in those tables but it might not be seemingly obvious which field contains what kind of data that’s why I decided to make a short reference for myself but maybe it will help also someone else.

To understand those tables I started with Central CLI to display content of each table which was as follows:

tabeleVTEPitp

Now let’s consider what kind of information we’ve got in each table and how they map to particular components in the environment.

VTEP Table – segment to VTEP IP bindings:

VNI – Logical Switch ID based on configured Segment pool

IP – VTEP IP (VMkernel IP) of host on which VM in VNI 6502 is running

Segment – VTEP Segment – in my case that’s only one L3 network which is used

MAC – MAC address of physical NIC configured for VTEP

MAC Table – VM MAC address to VTEP IP (host) mapping:

VNI – Logical Switch ID based on configured Segment pool

MAC – MAC address of VM accessible through VTEP IP displayed in column on the right.

VTEP-IP – IP of a host VTEP on which VM with MAC address from previous column is running.

ARP Table – Virtual Machine MAC to IP mapping:

VNI – Logical Switch ID based on configured Segment pool

IP – IP address of a Virtual Machine connected to that Logical Switch with following VNI

MAC – MAC address of Virtual Machine

 

To make it even easier here you have got a summary diagram with those mappings.

Drawing1

If you want to dig deeper into details how those tables are populated I strongly recommend watching this video from VMworld 2017 which clearly explains it step by step:

Alternative methods to create virtual switch.

Alternative methods to create virtual switch.

Creating virtual switch through GUI is well described in documentation and pretty intuitive using GUI. However, sometimes it might be useful to know how to do it with CLI or Powershell, thus making the process part of a script to automate initial configuration of ESXi after installation.

Here you will find commands which are necessary to create and configure a standard virtual switch using CLI and Powershell. Those examples will describe the process of vSwitch creation for vMotion traffic which involves VMkernel creation.

I. vSwitch configuration through CLI

  1. Create a vSwitch named “vMotion”

esxcli network vswitch standard add -v vMotion

  1. Check whether your newly created vSwitch was configured and is available on the list.

esxcli network vswitch standard list

  1. Add physical uplink (vmnic) to your vSwitch

esxcli network vswitch standard uplink add -u vmnic4 -v vMotion

  1. Designate an uplink to be used as active.

esxcli network vswitch standard policy failover set -a vmnic4 -v vMotion

  1. Add a port group named “vMotion-PG” to previously created vSwitch

esxcli network vswitch standard portgroup add -v vMotion -p vMotion-PG

  1. Add a VMkernel interface to a port group (Optional – not necessary if you are creating a vSwitch just for VM traffic)

esxcli network ip interface add -p vMotion-PG -i vmk9

  1. Configure IP settings of a VMkernel adapter.

esxcli network ip interface ipv4 set -i vmk9 -t static -I 172.20.14.11 -N 255.255.255.0

  1. Tag VMkernel adapter for a vMotion service. NOTE – service tag is case sensitive.

esxcli network ip interface tag add -i vmk9 -t vmotion

Done, your vSwitch is configured and ready to service vMotion traffic.

 

II. vSwitch configuration through PowerCLI

  1. First thing is to connect to vCenter server.

Connect-VIServer -Server vcsa.vclass.local -User administrator@vsphere.local -Password VMware1!

  1. Indicate specific host and create new virtual switch, assigning vmnic at the same time.

$vswitch1 = New-VirtualSwitch -VMHost sa-esx01.vclass.local -Name vMotion -NIC vmnic4

  1. Create port group and add it to new virtual switch.

New-VirtualPortGroup -VirtualSwitch $vswitch1 -Name vMotion-PG

  1. Create and configure VMkernel adapter.

New-VMHostNetworkAdapter -VMHost sa-esx01.vclass.local -PortGroup vMotion-PG -VirtualSwitch vMotion -IP 172.20.11.11 -SubnetMask 255.255.255.0 -vmotionTrafficEnabled $true