Trouble assigning user to group in OpenLDAP

Hello,

I am working on setup LDAP Server and facing issue related to assigning user to a group. Below is the LDAP structure i am using.

I have created Users,Groups and Servers ou's and sub ou's added to the same [bugbase,ftp,samba,svn,tcms,wiki] or Users as well as Groups OU.

Logged in as: cn=Manager,dc=bebolabs,dc=net

+--> dc=bebolabs,dc=net (3)
+--> ou=Groups (6)
| ---> ou=bugbase
| ---> ou=ftp
| ---> ou=samba
| ---> ou=svn
| ---> ou=tcms
| ---> ou=wiki
---> ou=Systems
+--> ou=Users (6)
| ---> ou=bugbase
| ---> ou=ftp
| ---> ou=samba
| ---> ou=svn
| ---> ou=tcms
| ---> ou=wiki

Now i created a user under Users->FTP->username ou and group created under Groups->FTP->groupname ou.

I assigned username under Users->FTP to group under Groups->FTP.

But on login from client machine below error is throwing and user is n

[root@ldapclnt ~]# su - sunny
id: cannot find name for group ID 500
[sunny@ldapclnt ~]$ id
uid=500(sunny) gid=500 groups=500
[sunny@ldapclnt ~]$

Please help me on this how to fix this.

Below is my ldapgroup.ldif and ldapuser.ldif

ldapgroup.ldif
dn: cn=sunny,ou=ftp,ou=Groups,dc=bebolabs,dc=net
objectClass: posixGroup
cn: sunny
gidNumber: 500
memberuid: sunny

ldapuser.ldif

dn: uid=sunny,ou=ftp,ou=Users,dc=bebolabs,dc=net
objectClass: inetOrgPerson
objectClass: posixAccount
objectClass: shadowAccount
uid: sunny
sn: sunny
givenName: sunny
cn: sunny
displayName: sunny
uidNumber: 500
gidNumber: 500
userPassword: {crypt}$1$tayZSy59$DcPHe6xQC3IvlNLE5u1ix1
gecos: sunny
loginShell: /bin/bash
homeDirectory: /home/sunny
shadowExpire: -1
shadowFlag: 0
shadowWarning: 7
shadowMin: 0
shadowMax: 99999
shadowLastChange: 15240