Bug#709648: netcfg: rerunning netcfg after preseeding no longer works as expected

[Matt Taggart <taggart@debian.org>]

Package: netcfg
Version: 1.108

As described in the install guide section B.4.2

  http://www.debian.org/releases/wheezy/amd64/apbs04.html.en#preseed-network

if you want to change the network settings after the initial boot and 
preseed loading, then you can use the work-around of

  "kill-all-dhcp; netcfg"

I successfully used this method with squeeze d-i in the past, but in 
attempting to use it with wheezy I have run into problems.

The system in question has multiple NICs plugged into multiple networks. 
The device 'eth0' is the public facing network, while my DHCP/tftp/PXE/http 
server for preseeding is on a private network (in this case 'eth4').

I am using 'interface=eth4' as a boot parameter and d-i successfully boots, 
brings up that interface with DHCP, loads the preseed and early_script and 
runs the work-around.

On the console netcfg restarts. But rather than attempting to configure 
eth4, it configures the first NIC that it detected link for which is eth0. 
So the result is both eth4 and eth0 are up (and on the same subnet, which 
is wrong for eth0).

In squeeze this worked, after netcfg restarted it would prompt me for the 
IP address (which I deliberately did not set) and properly preseeds the 
netmask/gateway/etc (which I did).

Maybe the recent changes for link detection are causing this?

Long term I'd like to see this fixed, but if there is any way to work 
around the problem that would be acceptable for the time being. Maybe there 
is some way of giving netcfg a hint of which device to use, or to disable 
the link detection stuff to prevent it using eth0.

Let me know if I can test anything or help in any other way.

Thanks,

-- 
Matt Taggart
taggart@debian.org