apt-get install ldap-utils

====== Basic query ======

Check if anonymous bind was accepted by server:

<code bash>
$ ldapsearch -H ldap://server -x

# extended LDIF
#
# LDAPv3
# base <dc=grinn-global,dc=com> (default) with scope subtree
# filter: (objectclass=*)
# requesting: ALL
#

# search result
search: 2
result: 32 No such object

# numResponses: 1
</code>

List root entries:
<code bash>
$ ldapsearch -H ldap://server -x -LLL -s base -b '' namingContexts
dn:
namingContexts: dc=example,dc=org
</code>


====== .ldaprc ======

<file | ~/.ldaprc>
BASE    dc=example,dc=org
URI     ldap://server
BINDDN  cn=admin,dc=example,dc=org
</file>

and verify if it works. First command will ask for password for user "cn=admin" or password can be specified by argument (second one):
<code bash>
ldapsearch -x -W
ldapsearch -x -w admin
</code>


====== cn=config =====

<code bash>
$ ldapsearch -x -W -LLL -s base -D 'cn=admin,cn=config' -b 'cn=config' dn
Enter LDAP Password: 
dn: cn=config
</code>

<code bash>
$ ldapsearch -x -W -LLL -D 'cn=admin,cn=config' -b 'cn=config' dn
Enter LDAP Password: 
...
dn: olcDatabase={1}mdb,cn=config
...
</code>

<code bash>
$ ldapsearch -x -W -LLL -D 'cn=admin,cn=config' -b 'cn=config' 'olcDatabase={1}mdb'
Enter LDAP Password: 

dn: olcDatabase={1}mdb,cn=config
objectClass: olcDatabaseConfig
objectClass: olcMdbConfig
olcDatabase: {1}mdb
olcDbDirectory: /var/lib/ldap
olcSuffix: dc=example,dc=org
olcAccess: {0}to attrs=userPassword,shadowLastChange by self write by dn="cn=admin,dc=example,dc=org" write by anonymous auth by * none
olcAccess: {1}to * by self read by dn="cn=admin,dc=example,dc=org" write  by * none
olcLastMod: TRUE
olcRootDN: cn=admin,dc=example,dc=org
olcRootPW: {SSHA}abcdef...
olcDbCheckpoint: 512 30
olcDbIndex: uid eq
olcDbIndex: mail eq
olcDbIndex: memberOf eq
olcDbIndex: entryCSN eq
olcDbIndex: entryUUID eq
olcDbIndex: objectClass eq
olcDbMaxSize: 1073741824
</code>


====== SASL ======

<code bash>
$ ldapsearch -x -LLL -s base -b "" supportedSASLMechanisms

dn:
supportedSASLMechanisms: SCRAM-SHA-1
supportedSASLMechanisms: GS2-IAKERB
supportedSASLMechanisms: GS2-KRB5
supportedSASLMechanisms: GSSAPI
supportedSASLMechanisms: GSS-SPNEGO
supportedSASLMechanisms: DIGEST-MD5
supportedSASLMechanisms: OTP
supportedSASLMechanisms: CRAM-MD5
supportedSASLMechanisms: NTLM
</code>




<code bash>
ldapsearch -x -W -D 'cn=admin,dc=example,dc=org'
ldapsearch -x -W -D 'uid=nextcloudsystemuser,ou=it,dc=grinn-global,dc=com'
</codE>