[Samba] error

[sandy.napoles at eccmg.cupet.cu]

First commands in BDC
host -t SRV _kerberos._udp.eccmg.cupet.cu.
Host _kerberos._udp.eccmg.cupet.cu. not found: 3(NXDOMAIN)

Second commands in BDC
host -t A server.eccmg.cupet.cu.
server.eccmg.cupet.cu has address 10.10.10.1

/etc/krb5.conf

[libdefaults]
       dns_lookup_realm = true
       dns_lookup_kdc = true
       default_realm = ECCMG.CUPET.CU


PD: My dns is not integrate to my samba4