Cadence and tunneling ports

Cadence periodically changes ports. There is a "base" connection port, and then some client ports. I recently helped a friend tunnel their license server connection so that he could push rectangles in the coffee shop.

As an example, the license port is specified:

CDS_LIC_FILE=5280@ecelinsrv3.ece.gatech.edu

However, Cadence opens a bunch of client ports, so you need to forward more than just the primary port. In the end, the forwarding script (tun.sh) looked like:

#!/bin/sh
ssh -C -2 -f -N -g \
-L 5280:ecelinsrv3.ece.gatech.edu:5280 \
-L 32801:ecelinsrv3.ece.gatech.edu:32801 \
-L 32815:ecelinsrv3.ece.gatech.edu:32815 \
ecelinsrv9.ece.gatech.edu

The higher number ports you need to find with:

netstat -tulpn

It will list groups of TCP ports, and add those to the script until you get a successful tunneling of the license. In my case, 32801 and 32815 where the secondary ports to forward that day. It is also worth noting that these seem to change every once in awhile, so if you cannot get a license, you will need to update the port list.