When upgrading machines from hardy to lucid, I always get asked about /etc/dhcp3/dhclient.conf. I don't believe we modify dhclient.conf (the only time we use dhcp is during install, we use manual network configuration after that), so I don't think we should be getting this prompt.
Setting up dhcp3-client (3.1.3-2ubuntu3) ...
Installing new version of config file /etc/dhcp3/dhclient-enter-hooks.d/debug ...
Installing new version of config file /etc/dhcp3/dhclient-exit-hooks.d/debug ...
Configuration file `/etc/dhcp3/dhclient.conf'
==> Modified (by you or by a script) since installation.
==> Package distributor has shipped an updated version.
What would you like to do about it ? Your options are:
Y or I : install the package maintainer's version
N or O : keep your currently-installed version
D : show the differences between the versions
Z : background this process to examine the situation
The default action is to keep your current version.
*** dhclient.conf (Y/I/N/O/D/Z) [default=N] ? d
--- /etc/dhcp3/dhclient.conf 2009-10-07 12:09:22.000000000 +0100
+++ /etc/dhcp3/dhclient.conf.dpkg-new 2010-04-01 23:55:44.000000000 +0100
@@ -1 +1,53 @@
-request subnet-mask, broadcast-address, time-offset, routers, domain-name, domain-name-servers, host-name, ntp-servers;
+# Configuration file for /sbin/dhclient, which is included in Debian's
+# dhcp3-client package.
+#
+# This is a sample configuration file for dhclient. See dhclient.conf's
+# man page for more information about the syntax of this file
+# and a more comprehensive list of the parameters understood by
+# dhclient.
+#
+# Normally, if the DHCP server provides reasonable information and does
+# not leave anything out (like the domain name, for example), then
+# few changes must be made to this file, if any.
+#
+
+option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
+
+send host-name "<hostname>";
+#send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
+#send dhcp-lease-time 3600;
+#supersede domain-name "fugue.com home.vix.com";
+#prepend domain-name-servers 127.0.0.1;
+request subnet-mask, broadcast-address, time-offset, routers,
+ domain-name, domain-name-servers, domain-search, host-name,
+ netbios-name-servers, netbios-scope, interface-mtu,
+ rfc3442-classless-static-routes, ntp-servers;
+#require subnet-mask, domain-name-servers;
+#timeout 60;
+#retry 60;
+#reboot 10;
+#select-timeout 5;
+#initial-interval 2;
+#script "/etc/dhcp3/dhclient-script";
+#media "-link0 -link1 -link2", "link0 link1";
+#reject 192.33.137.209;
+
+#alias {
+# interface "eth0";
+# fixed-address 192.5.5.213;
+# option subnet-mask 255.255.255.255;
+#}
+
+#lease {
+# interface "eth0";
+# fixed-address 192.33.137.200;
+# medium "link0 link1";
+# option host-name "andare.swiftmedia.com";
I can't reproduce that, installing hardy dhcp3-client and upgrading to the version in lucid.
The contents of the file shipped in hardy is longer than what you posted in your diff, and starts with:
# Configuration file for /sbin/dhclient, which is included in Debian's
# dhcp3-client package.
So it looks like something modified it... Or maybe there is a deeper issue when the contents in hardy actually comes from a dapper -> hardy upgrade. Would those affected boxes also have been upgraded from dapper ?