Now that I have my two RPi's up and running and accessible I have come up with a communication problem.
I will use ssh in the following explanation but rlogin and telnet have similar problems.
The wired and wireless parts of my network don't want to communicate with each other.
The raspberries can ssh each other over the wifi part of the network and my two Ubuntu machines can also ssh each other over the wired network.
However, I cannot ssh from Ubuntu to RPi3 when RPi3 is on wifi.
If I wire the RPi3 it can ssh to and from Ubuntu.
All the units can ping each other so some communication is happening.
Also, when Ubuntu (wired) tries to ssh the RPi (wifi) it gets as far as requesting a password. the password is entered and then it hangs. Control c does not escape the condition. I have to kill the terminal session.
I realise that this might not actually be a RPi problem but a more general routing problem.
Maybe there is some obscure setting in /etc/ssh or somewhere which may be causing this but I have no idea where to start looking.
Best Regards, Jack Fearnley