Client can't log to OD master

Hi,

I'm setting up a new network and followed the doc to do so as i'm not a specialist.

What I have and which (apparently) works is :

Server1
an internal DNS service - verified with changeip
a DHCP service

Server2
Open Directory master - with kerberos running, authentified binding not activated
afp - share point partaged with automount and group authorisation given

Server3
afp - share point partaged with automount and group authorisation given

In WGM I created two test users,
"U1" member of "grouptest" with home folders located on server2
"U2" member of "grouptest2" with home folders located on server3

I manually created the groups folders. First thing to note, the users home folder did not get created after I clicked the "create start" button in WGM. I suspected it is because I miswrote the path for the home folder in WGM, although I tried to copy the exemple given. E.g. I wrote : afp://FQDN/Hard disk name/folder name.

Client configuration
Regarding client config, I entered server2 FQDN in directory utilitary, it states the server responds normally. I was not able to bind, however, and I ignore if its necessary.

The problem
When I try to log using the client's login window, neither test user (u1,u2) succeed. I get an error message I cannot enter for the moment because an error occured.
On server2, the kerberos app shows it does not give any tickets.

I'd be grateful for any thoughts as I am not seeing which direction to follow.