Nodejs based VMWare VM serial console vSPC Proxy Server =======================================================

Usage no npm install needed!

<script type="module">
  import nodeVspc from '';


Nodejs based VMWare VM serial console vSPC Proxy Server


node-vspc is a Virtual Serial Port Concentrator (also known as a virtual serial port proxy) that makes use of the VMware telnet extensions.


  • Performance: Scales to thousands of VMs. (Tested with 4,000 with a 100 connections per second rate)
  • Persistent telnet port for the same VM


It is inspired by However, that script cannot scale to more than 500 VMs due to the usage of python's build in With NodeJS's async nature, node-vspc can scale to multiple thousands of VMs.


  • NodeJS 10
  • Redis 4

Configure VM to connect serial console to proxy

In order to configure a VM to use the virtual serial port concentrator, you must be running ESXi 4.1+. You must also have a software license level that allows you to use networked serial ports.

First, add a networked virtual serial port to the VM. Configure it as follows:

(*) Use Network
  (*) Server
  Port URI: node-vspc
  [X] Use Virtual Serial Port Concentrator:
  vSPC: telnet://hostname:proxy_port

NOTE: Direction MUST be Server

where hostname is the FQDN (or IP address) of the machine running the virtual serial port concentrator, and proxy_port is the port that you've configured the concentrator to listen for VM connections on.

Running the Concentrator

Before start, create a config.json and set the desired options. See config.sample.json for details.

Then, start the concentrator by using command:

node server.js

Getting the Telnet Port of a VM

When a VM is powered on, it will telnet to the concentrator's proxy listen port. The proxy will create a telnet server listening on a port. Users can telnet to this port, and connect to the VM's serial console.

node-vspc manages the telnet ports in Redis. User can query Redis to figure out which telnet port is mapped to which VM. The following command get the port of a VM named vm1 with id 993329f5-f353-4383-9a29-be60143f20d8:

redis-cli get 'Active:VM:Portvm1 (993329f5-f353-4383-9a29-be60143f20d8)'