Testing VXLAN VTEP VMkernel

To verify MTU and connectivity between VTEPs, use vmkping from an ESXi host console session. VTEP VMkernel is provisioned in a dedicated TCP/IP stack name, vxlan. To specify a TCP/IP stack on a vmkping, you can use either of the following formats:

vmkping ++netstack=vxlan <destination VTEP IP address> -d -s <packet size>  

Or:

vmkping -S vxlan <destination VTEP IP address> -d -s <packet size>  

The following are the command arguments:

• -d: Sets the DF (do not fragment) bit on IPv4 packets
• -S or ++netstack=: TCP/IP stack
• -s <packet size>: Sets the number of ICMP data bytes
• -I: Outgoing VMkernel interface

Ping the VTEP VMkernel using the packet size 1572 and the packet size 1472. If there is an MTU mismatch on vDS or the physical network, a ping using the packet size 1572 will fail but succeed on the packet size 1472. VXLAN can also be validated once we create a logical switch. This will be explained later in the Creating NSX Logical Switches recipe.