If netconfig didn't ask for an IP adress, it's probably because you selected DHCP (or maybe networkmanager, I don't know how that one works). In that case SERVER_HOST would ask the router (whose ip probably is 192.168.0.1) for an ip, and SERVER_HOST would be given 192.168.0.101.
Putting "192.168.0.101 SERVER_HOST.DN1 SERVER_HOST" in /etc/hosts at "local host" basically tells "local host" that "whenever I want to talk to SERVER_HOST or SERVER_HOST.DN1 I should address my messages to 192.168.0.101." So that `slogin SERVER_HOST` works after this change was to be expected.
However if you're using DHCP there is no guaranty that SERVER_HOST always will have 192.168.0.101 as its ip.
There was a small discussion some time ago on the merits of static ip + /etc/hosts versus dhcp, might be of interest to you: http://www.linuxquestions.org/questi...ip-4175436549/