What is mandatory is that your LDAP user needs a "role attribute", which is an attribute in LDAP which would indicate whole administration role a user would have when logging into an Airwave instance as an administrator. Without the "role attribute" which contains the role a user will have (typically root), the user cannot be authenticated: https://<ip address of your Airwave Server>/static/UserGuide/UserGuide.htm#AWUserGuide/Chapter2_Config/Configuring_LDAP_Authent.htm#03config_4106802467_1168308
It is much easier doing this with radius, where you would only have to return a radius attribute for management authentication, instead of altering your LDAP schema.