12.04 PXE installation - "not connected to internet" but it is: how to debug?

[henrylaw]

Installing 12.04.4 via TFTP/PXE from a local server. I get the language selection screen, but at the point where it says you need such-and-such disk space and you must be connected to the internet there's an X on the latter; i.e. the installer thinks there's no internet connection.

But if I switch to a TTY session with Ctrl-F1 I can see that eth0 is configured properly, and I can use wget to retrieve (for example) the text of BBC home page, thus showing that the connection is working fine.

How does the installer decide whether or not it's internet-connected? What can I do to get it to recognise the connection?

[grahammechanical]

Is the server machine connected to the internet? The installer is running from the server machine. Right?

Regards.

[henrylaw]

Is the server machine connected to the internet? The installer is running from the server machine. Right?

Correct; the server is connected to the internet (via an ADSL router in the usual way); it in turn provides DHCP, DNS forwarding and NAT to the clients, and it's one of those clients that I'm trying to build. The installer image comes via PXE and TFTP from that same server.

But as I said what puzzles me is that by shifting to a TTY on the client (Ctrl-Alt-F1 from the screen which is telling me that the machine isn't connected to the internet) I can do a successful nslookup on (say) bbc.co.uk, and then run wget successfully to get (say) bbc.co.uk/index.htm.