Hi Guys!
I don't know if it is possible, but.......

What I do:
sudo apt-get install slapd ldap-utils

ldapadd -Y EXTERNAL -H ldapi:/// -f /etc/ldap/schema/cosine.ldif
ldapadd -Y EXTERNAL -H ldapi:/// -f /etc/ldap/schema/nis.ldif
ldapadd -Y EXTERNAL -H ldapi:/// -f /etc/ldap/schema/inetorgperson.ldif
ldapadd -Y EXTERNAL -H ldapi:/// -f backend.example.com.ldif
ldapadd -x -D cn=admin,dc=felipemeirelles,dc=com,dc=br -W -f frontend.example.com.ldif

backend Base felipemeirelles:

# Load dynamic backend modules
dn: cn=module,cn=config
objectClass: olcModuleList
cn: module
olcModulepath: /usr/lib/ldap
olcModuleload: back_hdb

# Database settings
dn: olcDatabase=hdb,cn=config
objectClass: olcDatabaseConfig
objectClass: olcHdbConfig
olcDatabase: {1}hdb
olcSuffix: dc=felipemeirelles,dc=com,dc=br
olcDbDirectory: /var/lib/ldap
olcRootDN: cn=admin,dc=felipemeirelles,dc=com,dc=br
olcRootPW: 123456
olcDbConfig: set_cachesize 0 2097152 0
olcDbConfig: set_lk_max_objects 1500
olcDbConfig: set_lk_max_locks 1500
olcDbConfig: set_lk_max_lockers 1500
olcDbIndex: objectClass eq
olcLastMod: TRUE
olcDbCheckpoint: 512 30
olcAccess: to attrs=userPassword by dn="cn=admin,dc=felipemeirelles,dc=com,dc=br" write by anonymous auth by self write by * none
olcAccess: to attrs=shadowLastChange by self write by * read
olcAccess: to dn.base="" by * read
olcAccess: to * by dn="cn=admin,dc=felipemeirelles,dc=com,dc=br" write by * read
   


Frontend Base felipemeirelles:

# Create top-level object in domain
dn: dc=felipemeirelles,dc=com,dc=br
objectClass: top
objectClass: dcObject
objectclass: organization
o: Example Organization
dc: felipemeirelles
description: LDAP SIJ

# Admin user.
dn: cn=admin,dc=felipemeirelles,dc=com,dc=br
objectClass: simpleSecurityObject
objectClass: organizationalRole
cn: admin
description: LDAP administrator
userPassword: 123456

dn: ou=people,dc=felipemeirelles,dc=com,dc=br
objectClass: organizationalUnit
ou: people

dn: ou=groups,dc=felipemeirelles,dc=com,dc=br
objectClass: organizationalUnit
ou: groups

dn: uid=contato,ou=people,dc=felipemeirelles,dc=com,dc=br
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
uid: contato
sn: Contato
givenName: Contato
cn: Contato Contato
displayName: Contato
uidNumber: 1000
gidNumber: 10000
userPassword: 123456
gecos: Contato Contato
loginShell: /bin/bash
homeDirectory: /home/contato
shadowExpire: -1
shadowFlag: 0
shadowWarning: 7
shadowMin: 8
shadowMax: 999999
shadowLastChange: 10877
mail: contato@felipemeirelles.com.br
postalCode: 31000
l: Toulouse
o: Example
mobile: +33 (0)6 xx xx xx xx
homePhone: +33 (0)5 xx xx xx xx
title: System Administrator
postalAddress:
initials: JD

dn: cn=felipemeirelles,ou=groups,dc=felipemeirelles,dc=com,dc=br
objectClass: posixGroup
cn: felipemeirelles
gidNumber: 10000


Ok ? This is my first base.

Now, i try added more:

ldapadd -Y EXTERNAL -H ldapi:/// -f backend_sij_com.example.com.ldif
ldapadd -x -D cn=admin,dc=sij,dc=com,dc=br -W -f frontend_sij_com.example.com.ldif
ldap_bind: Invalid credentials (49)


BASE SIJ.COM.BR ( Other backend: backend_sij_com.example.com.ldif )

# Load dynamic backend modules
dn: cn=module,cn=config
objectClass: olcModuleList
cn: module
olcModulepath: /usr/lib/ldap
olcModuleload: back_hdb

# Database settings
dn: olcDatabase=hdb,cn=config
objectClass: olcDatabaseConfig
objectClass: olcHdbConfig
olcDatabase: {1}hdb
olcSuffix: dc=sij,dc=com,dc=br
olcDbDirectory: /var/lib/ldap
olcRootDN: cn=admin,dc=sij,dc=com,dc=br
olcRootPW: 123456
olcDbConfig: set_cachesize 0 2097152 0
olcDbConfig: set_lk_max_objects 1500
olcDbConfig: set_lk_max_locks 1500
olcDbConfig: set_lk_max_lockers 1500
olcDbIndex: objectClass eq
olcLastMod: TRUE
olcDbCheckpoint: 512 30
olcAccess: to attrs=userPassword by dn="cn=admin,dc=sij,dc=com,dc=br" write by anonymous auth by self write by * none
olcAccess: to attrs=shadowLastChange by self write by * read
olcAccess: to dn.base="" by * read
olcAccess: to * by dn="cn=admin,dc=sij,dc=com,dc=br" write by * read



Other FrontEnd: frontend_sij_com.example.com.ldif
# Create top-level object in domain
dn: dc=sij,dc=com,dc=br
objectClass: top
objectClass: dcObject
objectclass: organization
o: Example Organization
dc: sij
description: LDAP SIJ

# Admin user.
dn: cn=admin,dc=sij,dc=com,dc=br
objectClass: simpleSecurityObject
objectClass: organizationalRole
cn: admin
description: LDAP administrator
userPassword: 123456

dn: ou=people,dc=sij,dc=com,dc=br
objectClass: organizationalUnit
ou: people

dn: ou=groups,dc=sij,dc=com,dc=br
objectClass: organizationalUnit
ou: groups

dn: uid=caho.lopes,ou=people,dc=sij,dc=com,dc=br
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
uid: caho.lopes
sn: caho
givenName: Caho
cn: Caho Lopes
displayName: caho
uidNumber: 1000
gidNumber: 10000
userPassword: testecahosij
gecos: Caho Lopes
loginShell: /bin/bash
homeDirectory: /home/caho.lopes
shadowExpire: -1
shadowFlag: 0
shadowWarning: 7
shadowMin: 8
shadowMax: 999999
shadowLastChange: 10877
mail: caho.lopes@sij.com.br
postalCode: 31000
l: Toulouse
o: Example
mobile: +33 (0)6 xx xx xx xx
homePhone: +33 (0)5 xx xx xx xx
title: System Administrator
postalAddress:
initials: JD

dn: cn=sij,ou=groups,dc=sij,dc=com,dc=br
objectClass: posixGroup
cn: sij
gidNumber: 10000


root@PythonAPP:~# ldapadd -d 65535 -x -D cn=admin,dc=sij,dc=com,dc=br -W -f frontend_sij_com.example.com.ldif
ldap_create
Enter LDAP Password:
ldap_sasl_bind
ldap_send_initial_request
ldap_new_connection 1 1 0
ldap_int_open_connection
ldap_connect_to_host: TCP localhost:389
ldap_new_socket: 4
ldap_prepare_socket: 4
ldap_connect_to_host: Trying ::1 389
ldap_pvt_connect: fd: 4 tm: -1 async: 0
ldap_open_defconn: successful
ldap_send_server_request
ber_scanf fmt ({it) ber:
ber_dump: buf=0x7f75c3f32540 ptr=0x7f75c3f32540 end=0x7f75c3f32570 len=48
  0000:  30 2e 02 01 01 60 29 02  01 03 04 1c 63 6e 3d 61   0....`).....cn=a 
  0010:  64 6d 69 6e 2c 64 63 3d  73 69 6a 2c 64 63 3d 63   dmin,dc=sij,dc=c 
  0020:  6f 6d 2c 64 63 3d 62 72  80 06 31 32 33 34 35 36   om,dc=br..123456 
ber_scanf fmt ({i) ber:
ber_dump: buf=0x7f75c3f32540 ptr=0x7f75c3f32545 end=0x7f75c3f32570 len=43
  0000:  60 29 02 01 03 04 1c 63  6e 3d 61 64 6d 69 6e 2c   `).....cn=admin, 
  0010:  64 63 3d 73 69 6a 2c 64  63 3d 63 6f 6d 2c 64 63   dc=sij,dc=com,dc 
  0020:  3d 62 72 80 06 31 32 33  34 35 36                  =br..123456      
ber_flush2: 48 bytes to sd 4
  0000:  30 2e 02 01 01 60 29 02  01 03 04 1c 63 6e 3d 61   0....`).....cn=a 
  0010:  64 6d 69 6e 2c 64 63 3d  73 69 6a 2c 64 63 3d 63   dmin,dc=sij,dc=c 
  0020:  6f 6d 2c 64 63 3d 62 72  80 06 31 32 33 34 35 36   om,dc=br..123456 
ldap_write: want=48, written=48
  0000:  30 2e 02 01 01 60 29 02  01 03 04 1c 63 6e 3d 61   0....`).....cn=a 
  0010:  64 6d 69 6e 2c 64 63 3d  73 69 6a 2c 64 63 3d 63   dmin,dc=sij,dc=c 
  0020:  6f 6d 2c 64 63 3d 62 72  80 06 31 32 33 34 35 36   om,dc=br..123456 
ldap_result ld 0x7f75c3f2a2b0 msgid 1
wait4msg ld 0x7f75c3f2a2b0 msgid 1 (infinite timeout)
wait4msg continue ld 0x7f75c3f2a2b0 msgid 1 all 1
** ld 0x7f75c3f2a2b0 Connections:
* host: localhost  port: 389  (default)
  refcnt: 2  status: Connected
  last used: Wed Jul 20 17:53:53 2011


** ld 0x7f75c3f2a2b0 Outstanding Requests:
 * msgid 1,  origid 1, status InProgress
   outstanding referrals 0, parent count 0
  ld 0x7f75c3f2a2b0 request count 1 (abandoned 0)
** ld 0x7f75c3f2a2b0 Response Queue:
   Empty
  ld 0x7f75c3f2a2b0 response count 0
ldap_chkResponseList ld 0x7f75c3f2a2b0 msgid 1 all 1
ldap_chkResponseList returns ld 0x7f75c3f2a2b0 NULL
ldap_int_select
read1msg: ld 0x7f75c3f2a2b0 msgid 1 all 1
ber_get_next
ldap_read: want=8, got=8
  0000:  30 0c 02 01 01 61 07 0a                            0....a..         
ldap_read: want=6, got=6
  0000:  01 31 04 00 04 00                                  .1....           
ber_get_next: tag 0x30 len 12 contents:
ber_dump: buf=0x7f75c3f33920 ptr=0x7f75c3f33920 end=0x7f75c3f3392c len=12
  0000:  02 01 01 61 07 0a 01 31  04 00 04 00               ...a...1....     
read1msg: ld 0x7f75c3f2a2b0 msgid 1 message type bind
ber_scanf fmt ({eAA) ber:
ber_dump: buf=0x7f75c3f33920 ptr=0x7f75c3f33923 end=0x7f75c3f3392c len=9
  0000:  61 07 0a 01 31 04 00 04  00                        a...1....        
read1msg: ld 0x7f75c3f2a2b0 0 new referrals
read1msg:  mark request completed, ld 0x7f75c3f2a2b0 msgid 1
request done: ld 0x7f75c3f2a2b0 msgid 1
res_errno: 49, res_error: <>, res_matched: <>
ldap_free_request (origid 1, msgid 1)
ldap_parse_result
ber_scanf fmt ({iAA) ber:
ber_dump: buf=0x7f75c3f33920 ptr=0x7f75c3f33923 end=0x7f75c3f3392c len=9
  0000:  61 07 0a 01 31 04 00 04  00                        a...1....        
ber_scanf fmt (}) ber:
ber_dump: buf=0x7f75c3f33920 ptr=0x7f75c3f3392c end=0x7f75c3f3392c len=0

ldap_msgfree
ldap_err2string
ldap_bind: Invalid credentials (49)


In the slapd -D, the log:

.....
  0000:  30 2e 02 01 01 60 29 02                            0....`).         
ldap_read: want=40, got=40
  0000:  01 03 04 1c 63 6e 3d 61  64 6d 69 6e 2c 64 63 3d   ....cn=admin,dc= 
  0010:  73 69 6a 2c 64 63 3d 63  6f 6d 2c 64 63 3d 62 72   sij,dc=com,dc=br 
  0020:  80 06 31 32 33 34 35 36                            ..123456         
ldap_read: want=8 error=Resource temporarily unavailable
ldap_write: want=14, written=14
  0000:  30 0c 02 01 01 61 07 0a  01 31 04 00 04 00         0....a...1....   
ldap_bind: Invalid credentials (49)





Help ?

Thanks!
ldap_read: want=8, got=0