dynamic configuration of wired network interfaces looks quite broken

[Michal Jaegermann]

Before I will waste more time on that does anybody know what broke
dhclient on _wired_ interfaces?

I was away for quite a while now and upon return I found that although
I can still use DHCP to configure wireless interfaces of my laptops
this is totally different story for _wired_ ones.  In the first case I
see in logs:

 dhclient[2304]: DHCPDISCOVER on ath0 to 255.255.255.255 port 67 interval 20
 dhclient[2304]: DHCPOFFER from 192.168.xx.yy
 dhclient[2304]: DHCPREQUEST on ath0 to 255.255.255.255 port 67
 dhclient[2304]: DHCPACK from 192.168.xx.yy

and an interfaces comes up.  With a wired one I get:

 dhclient[2135]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
 dhclient[2135]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
 dhclient[2135]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
 dhclient[2135]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
 dhclient[2135]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 14
 dhclient[2135]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
 dhclient[2135]: No DHCPOFFERS received.

and no networking.  This happens with my test rawhide installation,
both before and after I applied a big pile of pending updates, and
with Fedora 12 installations with all available updates applied.

In all cases dhclient here talks to the same DHCP server, which
happens to be some version of dnsmasq running on a WRTG router, and on
the same network but only through different network interfaces.  My
test machine does not have a wireless one but only a wired which up to
now was configured to use DHCP, and which I would prefer to keep that
way for various reasons, so you can see the trouble.

Asigning static IPs on wired interfaces makes a network to go "alive"
again but this is quite bad option for laptops which travel from time
to time with "foreign" networks not always wireless and a dynamic
configuration should work anyway.  There is still an option of
wireless breaking the same way on the next update.  Luckily my other
not running Feodra "wired DHCP clients", like a DHCP _requiring_
network interface of my printer - for example, still work just fine as
before (and this shows that my DHCP server in use is fine).

This does not look as a directly dhclient issue as reverting that to
older version did not change anything (and it seems that I went back
far enough).  Also a status of selinux, on which I practically gave up
anyway, is irrelevant.  A search through bugzilla, quite possibly as
unreliable as usual, also did not make me much wiser.  My suspicion
would be some other library doing some "creative things" with IPv6 but
I do not have a smoking gun.  I would file a bugzilla report but I
have not a clue against what.  Maybe this is already a well know
problem?   Hm, iptables?  I did not try that yet.

Again - the breakage may show up any time in the last two months and
I had no way to notice it but only now.

  Michal