No ethernet link with port replicator

[Stefan Renner]

The wired ethernet connection works properly in the common way. But with the use of a port replicator this becomes weird.

When I dock-in while the computer is running, I get no ethernet link.

/var/log/syslog shows for this:

Oct 30 13:06:44 srenW540 NetworkManager[18816]: <info> Activation (eth0) Beginning DHCPv4 transaction (timeout in 45 seconds)
Oct 30 13:06:44 srenW540 dhclient: Internet Systems Consortium DHCP Client 4.2.4
Oct 30 13:06:44 srenW540 NetworkManager[18816]: <info> (eth0): DHCPv4 state changed nbi -> preinit
Oct 30 13:06:44 srenW540 dhclient: DHCPREQUEST of 9.152.205.151 on eth0 to 255.255.255.255 port 67 (xid=0x3d811fa9)
Oct 30 13:06:50 srenW540 dhclient: message repeated 2 times: [ DHCPREQUEST of 9.152.205.151 on eth0 to 255.255.255.255 port 67 (xid=0x3d811fa9)]
Oct 30 13:06:57 srenW540 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x5e7a1a94)
Oct 30 13:07:00 srenW540 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7 (xid=0x5e7a1a94)
Oct 30 13:07:07 srenW540 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8 (xid=0x5e7a1a94)
Oct 30 13:07:15 srenW540 dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 21 (xid=0x5e7a1a94)
Oct 30 13:07:29 srenW540 NetworkManager[18816]: <warn> (eth0): DHCPv4 request timed out.
Oct 30 13:07:29 srenW540 NetworkManager[18816]: <info> (eth0): canceled DHCP transaction, DHCP client pid 20276

The ONLY possible way to get an ethernet link with the port replicator is this:

1. Shut down notebook and dock-out
2. Plug off the port replicator's AC (!)
3. Wait a few seconds
4. Dock-in and plugin-in the replicator's AC
5. Boot

Now, the ethernet link will be established. BUT: If you dock-out and dock-in now, the link gets not established as well.
This is extremely uncomfortable and the use of a port replicator is a mess with this.

Interface DownUp when the link can not be established does not work as well.
Please help!