Hi everyone,
I've "compiled" all your input, here is the output:
The cables are all cat5e, which should be OK. But to be sure I've managed to find a cat6 cable, but as expected, it did not change anything. So the cables are not the problem.
Then I added "speed 1000" and "duplex full" to the two port configuration, but: no change.
Next step: Try "mode on" -> Does not work because "on" is PAGP which is not compatible with LACP.
Go on: Try "switchport nonegotiate" -> No change in behaviour.
When the servers are booting (BIOS, not yet OS) then there is no bonding/etherchannel available. Both ports are independent. That should be no problem for the "mode active/passive" and it works as expected, the server can do DHCP/PXE during boot. But it takes a long time until the server gets an IP from DHCP because it takes so long to get the protocol up.
Is your server supporting LACP?
During BIOS boot: no While running OS: yes
How are is the bonding configured on the interfaces?
During BIOS boot: not configured While running OS: configured with linux bonding (that works fine)
Maybe this will stay a mysterium =)
I wish everyone good luck in finding the easter-eggs. (Maybe this behavior is a cisco-easter-egg and solved after easter, who knows =)
Cheers, Tobias