I'll add in that you could run a fairly simple program on Linux that simply blasted out very small UDP packets and point it at a VMS node - any port is fine - you'll drive up the interrupt mode on that box. You won't need much traffic. Smaller packets are better because you want to punch it with lots of packets. It won't be much actual bandwidth. VMS performance here is kind of sad.

As a bonus feature, if your VMS TCP/IP stack is configured to send ICMP replies when there is nothing there at the given port, you'll create even more grief because now the stack is busy trying to receive the blast you give it and send out replies too.