upgrade to precise required a change in /etc/network/interfaces

[Adam Funk]

Yesterday I upgraded my home desktop, which has been using a static
LAN IP address for years, to Precise, and it had no DNS after
restarting.  The /etc/network/interfaces file contained this stanza:

#v+
auto eth0
iface eth0 inet static
      address 192.168.123.4
      netmask 255.255.255.0
#v-

which had previously worked without any problem.  I figured out after
some fiddling that adding a dns-nameserver line to the stanza made
everything work again.  But I'm curious: why did this upgrade suddenly
require that change?

Thanks,
Adam