LDAP usuage

To see if a user has access to a servers, and to check to which groups he belong, you can use ldapsearch:
ldapsearch -x uid=username

#extended LDIF
#LDAPv3
#base <> with scope subtree
#filter: uid=USERNAME
#requesting: ALL
#USERNAME, Users, People, dom.be
dn: uid=USERNAME,ou=Users,ou=People,dc=dom,dc=be
memberOf: cn=somethingie,ou=hostaccess,ou=groups,dc=dom,dc=be
memberOf: cn=exmaple,ou=sudousersgroups,ou=groups,dc=dom ,dc=be
sshPublicKey: ssh-rsa ADFDBVDFCBDLo016Q1IquxZ0we9xW2Y+QF5oVqh6C5dJWrvoPSk4E4dg
d6ArGigJZV6Ea+LcreBRnxtmEJhdqimqlksjdfiKLJFDSIODHEu9TrA7Jol0Bm8RlpOuV+7M4
kQhOZSWyW4xSWI8+/qoS8ItQ6DyqC/gnP8MVt73aSRCOcn+JgfScpgjcVIXU9JCQujtGpCR7RRrwB
CKbml9vxo9CN1qimLM/e3awzHN/AZwOcw7GSDFFSSDFp5apTStAjeiKcWJXo4nJtvMBit+yHVC8
UjDYdbXL USERNAME@PC.dom.net
objectClass: inetOrgPerson
objectClass: organizationalPerson
objectClass: person
objectClass: top
objectClass: posixAccount
objectClass: ldapPublicKey
objectClass: shadowAccount
objectClass: inetUser
cn: USERNAME
preferredLanguage: en
gidNumber: 20599
gecos: Bob De Bouwer
uid: USERNAME
homeDirectory: /home/USERNAME
loginShell: /bin/bash
uidNumber: 987456985
displayName: Bob De Bouwer 20599
sn: Bob
mail: debouwer.Bob@dom.com
givenName: debouwer

#search result
search: 2
result: 0 Success

#numResponses: 2
#numEntries: 1