Bug#652573: busybox-udeb: debian stable busybox udhcp client does not support /32 netmasks

[Conrad Wood <cnw@conradwood.net>]

On 2 Jun 2012, at 20:04, Petter Reinholdtsen wrote:

> 
> [Michael Tokarev]
>> Peter, can you give some more details please, maybe some hints on how
>> to setup the test environment / dhcp server?
> 
> Sorry, I do not have more details any more.  If I remember correctly,
> the problem was with installing Debian on virtual machines where the
> installation environment only provided one IP address to the virtual
> ethernet and used this to set the IP using DHCP.
> 
> Probably better to ask Conrad Wood for more details. Cc to him.
> -- 
> Happy hacking
> Petter Reinholdtsen
> 

Hi Petter,

In some "cloud" environments, including ours, we configure an ethernet device with a single /32 IP Address. Say, for example 5.6.7.8/32. The Default Gateway is, for example, 9.10.11.12. The linux kernel and BSD happily work as desired and send out an arp request out of the ethernet device and route _everything_ to the default gateway. 
Configuring this manually is straightforward and works as desired.
Using the ISC-DHCP client also works as desired. It picks up IP, Netmaks and gateway perfectly well.
However, in the installer, with the busybox dhcp client, it stalls and claims it is unable to configure the network interfaces. Anything _apart_ from /32 (say /31, /30 etc.) works ok. But then the gateway won't be reachable, as the kernel then tries to do 'propper(?)' routing instead of just forwarding the packets.
Please let me know if you need more information. I can provide a remote console to a Virtual Machine where this problem is reproducible, if that helps.

Conrad