dejasync gets from the Deja.properties file the list of maps managed by Deja for NIS. These are lines that start with the NIS_MAPS token.
For each map in the Deja.properties file, dejasync creates a new map definition by copying the following tokens from the nis.mapping file into the Deja.properties file:
NIS_FILTER
NIS_DOMAIN
NIS_ROOT
NIS_NAMINGATTR
NIS_OCLASS
If these tokens exist in the Deja.properties file, dejasync updates them. If they do not exist, it creates them.