Server 2003 no puede conectarse a dominio NT

Hola,

A conectar un Server 2003 (MARIA)(IP privada)a dominio NT (MAMA_NT)de
distinta red (IP publica) me sale el siguiente error. Creo que la
configuracion esta bien.
Alguna pista de que pasa?

11/16 13:34:46 NetpDoDomainJoin
11/16 13:34:46 NetpMachineValidToJoin: 'MARIA'
11/16 13:34:46 NetpGetLsaPrimaryDomain: status: 0x0
11/16 13:34:46 NetpMachineValidToJoin: status: 0x0
11/16 13:34:46 NetpJoinDomain
11/16 13:34:46 Machine: MARIA
11/16 13:34:46 Domain: MAMA_NT
11/16 13:34:46 MachineAccountOU: (NULL)
11/16 13:34:46 Account: MAMA_NT\Administrador
11/16 13:34:46 Options: 0x27
11/16 13:34:46 OS Version: 5.2
11/16 13:34:46 Build number: 3790
11/16 13:34:46 NetpValidateName: checking to see if 'MAMA_NT' is valid as
type 3 name
11/16 13:34:46 NetpValidateName: 'MAMA_NT' is not a valid Dns domain name:
0x2554
11/16 13:34:46 NetpCheckDomainNameIsValid [ Exists ] for 'MAMA_NT' returned
0x0
11/16 13:34:46 NetpValidateName: name 'MAMA_NT' is valid for type 3
11/16 13:34:46 NetpDsGetDcName: trying to find DC in domain 'MAMA_NT',
flags: 0x1020
11/16 13:34:48 NetpDsGetDcName: failed to find a DC in the specified domain:
0x54b
11/16 13:34:48 NetpDoDomainJoin: status: 0x54b

Un saludo
Roberto