I'm using FreeBSD-6.2 for samba PDC. I'm using tdbsam for password backend. I created some shell script to maintain unix users and groups. My "add group script" prints a gid when a unix group was successfully created. But the gid is not used by samba. So "net rpc vampire" could not map NT groups and Unix groups. I think that following code should be fixed. utils/net_rpc_samsync.c line 616 if ((grp = getgrnam(name)) == NULL){ is if ((grp = getgrgid(gid)) == NULL){ I applied this to my samba, I think it works correctly.