Bug#652573: /32 netmask

[Conrad Wood <cnw@conradwood.net>]

as the original reporter of the issue, /32 instructs linux (and windows
2000+ and MacOS) to send all traffic to the gateway, never local.
This is actually fairly common in switched & shared datacenters and
avoids the need for private ip-addresses between two hops, or worse
using valuable IPv4 addresses for routing hops.

Noteworthy is that isc-dhcp does The Right Thing in my opinion, by
passing any semantically correct netmask on to the underlying layer
without logical test. That should be up to the network layer wether or
not it can digest it.

uDHCP seems to filter it prematurely.

Whilst setting IP & netmask manually works around this issue it is
inconvenient for users.

And yes... it is a bit of a hack that became common rather than one that
was designed and RFC'ed afaik ;-)