Backing to a null device with Server1 as the gateway was the same result. Almost 1 MBs. HP DP support so far has failed to live up to a standard.
I am thinking of activating another port in the fileserver and assigning it to a different vlan. And use that for the backup instead of the port we are using now. But I will see what the support has to say first (giving benefit of doubt) or if we can have someone else take a look at the case.