Enabling Performance Mode or Lite Mode

vMX can be configured to run in two modes depending on the use case.

• Lite mode—Needs fewer resources in terms of CPU and memory to run at lower bandwidth.

• Performance mode—Needs higher resources in terms of CPU and memory to run at higher bandwidth.

  Note:

  Starting in Junos OS Release 15.1F6 and later releases performance mode is enabled implicitly by default.

  When you enable performance mode, make sure you have configured the proper number of vCPUs (four or more VPCUs) and memory for your VMs based on your use case.

You can explicitly enable lite-mode. If you are using paravirtualized network interfaces such as virtio (for KVM) or VMXNET3 (for VMware) for lab simulation use cases, you can disable performance mode by including the lite-mode statement at the [edit chassis fpc 0] hierarchy level.

You can explicitly enable performance mode by including the performance-mode statement at the [edit chassis fpc 0] hierarchy level.

Starting with Junos OS Release 17.3R1, the show chassis hardware command displays the mode in which vMX is running in the part number field for the FPC. RIOT-PERF indicates performance mode and RIOT-LITE indicates lite mode. For example, this output indicates that vMX is running in lite mode.

Table 1 highlights some of the challenging features which are supported in the Fast Path and some which are not supported. Features which are not supported in the Fast Path still work but they get less than 100K PPS per worker vCPU.