[NickPGSmith]

Thanks for your suggestions.

> Why not just make your life easy and use Booterizer?

My general approach is to make my life as complicated as possible; that way I learn more. Or get frustrated. ;-) So I have learned some Docker in this process as well as about SGI...

So I am aware that the SGI needs to talk IPv4, but was somewhat thrown off my netstat showing IPv6. In fact this seems to be a Linux artefact, see here: https://www.ajfriesen.com/netstat-shows-...only-host/

I am not quite sure what I have changed, but currently I got a response from BOOTP server in Docker, and loaded up sash and fx.64 on the Octane.

One blocker was not realising how the Docker container was working with regards to which bootptab it was reading: I didn't know I had to create my own image and copy my settings over into it.

Also I didn't help by not using the correct tcpdump command. This is what I should have used:
tcpdump -i 2 -n "src 10.0.0.2 or portrange 67-68

So, now I got to running:
bootp()/inst/dist/miniroot/unix.IP30

where it transfers a bunch of stuff over the network, seems to start a kernel and then falls over with an error... a problem for another day