OK, this is all just fine! We should be able to get you through this pretty easily. While typing a response to your first post, the second showed up. What you found is what I suspected. I will give you a brief explanation later...
The one that I used was meant to convert HDMI signal to D-SUB, not the other way round. I ordered one that will do just that, just in case.
Hopefully we won't need it as we will try to use the remote control feature. We may have to fight a bit with Java - we'll see.
Update on DHCP stuff:
Yes, indeed the new MB shows different MAC address. But strangely, even though I have connected two LAN cables into the server and on both the LEDs are flashing, the router only shows one MAC address from the MB. I know this because I ruled out all other MAC addresses on the DHCP server of my router. And the MAC addresses of the MB start with specific set of alphabet/numbers, but on the DHCP server there is only one such thing.
So there is no other IP address. There is just one. It was 192.168.0.110 when I posted the screenshot, but now it is 192.168.0.106.
By default our MB's IPMI is bound to LAN1 - the board has in fact three MAC addresses, but both LAN1 and the BMC can be accessed through a single connection to LAN1. A connection to LAN2 is not advised if it is not on a different subnet from LAN2, (something a typical consumer router setup will not provide) - if you make such a connection on the same subnet it may appear to work but in fact be doing nothing (not carrying any traffic). So, I suggest you proceed from here with only one connection to LAN1 - through which you will access the BMC (IPMI) and FreeNAS once we find its IP and you can see the MAC address of the LAN1 interface in your router (at which time you'll have both MACs and can then reserve/assign IP addresses for them).
As soon as you are ready to make a trial run, from your laptop client (BTW I'm in windowze-land and don't know how Ubuntu behaves) open up the IPMI screen, click on "Remote Control" and select "Console Redirection", then press the "Java Console" button. Then will have some interaction with Java (maybe even requesting updates to it) but hopefully you will arrive at a point where you have the FreeNAS console window which will contain the web GUI interface IP address... if FreeNAS has indeed booted up successfully.
If it's not there it's likely that your boot device was not selected in BIOS. In that case, leave the console window open and go back to the "Remote Control" tab, but this time select "Server Power Control" and select "Reset Server" radio button (the default) and hit "Perform Action".
Watch the console window as the server reboots and when prompted access the BIOS to adjust the boot order as necessary. Once that is done the server should boot up successfully and the console screen should appear, and you can find the GUI address for FreeNAS.
Once you access it you can capture the MAC addresses and set up the IP's - and you should be good to go.
Let us know how you get on.
I don't really think you need a "Good Luck" wish now as you are so close, but I'll give you one anyway - "Good Luck!" - just in case.
EDIT: Here's a screenshot of what you'll see under "Remote Control, Console Redirection":