[Erwin]

The ssh -W option -- which replaces netcat -- is relatively new. E.g. Redhat 5.x did not have it, nor did Ubuntu 10.04 LTS. Until OpenSSH 5.4 netcat was the way to do this sort of proxying.

[stock_toaster]

I ran into an issue[1] with the combination of -W and control persist -- using openssh versions < 6.0.

netcat worked fine.

  [1]: https://news.ycombinator.com/item?id=4678117