This is because in your old dfm server you have set it to a specify name.
By default the option is empty and pick up the hostname.If you set it to a specify value then that is used.
Below is the example.
[root@lnx ~]# dfm options list | grep -i localHostName
localHostName
[root@lnx ~]#
[root@lnx~]# dfm options list localHostName
Option Value
--------------- ------------------------------
localHostName
[root@lnx~]#
This wouldnt have been in your case.Hope it explains why .
Regards
adai