Stops booting after DHCP Request

Hi everyone,
I've got the following Problem with my OMV Installation:

Yesterday I let the Update Manager do it´s Job an made the following Updates:

libgd2-xpm openmediavault
openssh-client openssh-server tzdata

While doing the Updates I just got a Coffee and after coming Bad I got the Error Message:

Bad Gateway

Since then I can´t open the WebGui or an SSH Connection. Now I attached a Monitor to my System an while booting it just stops after the DHCP Request.

Anyone an Idea what to do now?

Hi,
sorry for late answer. I'm moving to a new flat at the moment

Here are the answers for the questions:

Hardware:
The System runs on an HP Proliant Microserver Gen 7 N36l. Did it for a year or so...

IPv6 not as I know. I didn't changed anything on the Adapter as I remeber.

Recovery Kernel:

Same behavior as befor. Tried it without a Network Cable doesn't change it. It just stops with the Message No DHCPOFFERS recieved.

Ping:

Yes, I can do a Ping, and I got an Answer from the System but it doesn't start SSH or anything.

No one an idea?

No, anyway I installed OMV new but ran into an different Problem while mounting my Raid 1...
Well, I opend a new Thread..New Problem, new Thread i think