Get All AD Groups using LDAP in C#

Issue: LDAP Query not pulling all the Active Directory Groups (including subgroups) available in the given domain.

Solution:

To retrieve a set of results that is larger than 1000 items, you must set SizeLimit to its default value (zero) and set PageSize to a value that is less than or equal to 1000.

Concept Source: Click here

public static DataTable GetAllActiveDirectoryGroups(string ldapServer, string ldapUserName, string ldapPassWord)

        {

            DataTable dt = new DataTable();

            DataRow dr;

            DirectoryEntry de = new DirectoryEntry(ldapServer);

            de.Username = ldapUserName;

            de.Password = ldapPassWord;

            DirectorySearcher deSearch = new DirectorySearcher(de.Path);

            SearchResultCollection results;

            dt.Columns.Add("GroupName");

            try

            {

                deSearch.Filter = ("(&(objectCategory=group))");

                deSearch.SearchScope = SearchScope.Subtree;

                //deSearch.SizeLimit = 10000;

                deSearch.PageSize = 1000;

                results = deSearch.FindAll();

                foreach (SearchResult result in results)

                {

                    dr = dt.NewRow();

                    dr["GroupName"] = result.Properties["cn"][0].ToString();

                    dt.Rows.Add(dr);

                }

                de.Close();

            }

            catch (Exception ex)

            {

                throw ex;

            }

            finally

            {

                if (deSearch != null)

                {

                    deSearch.Dispose();

                }

                if (de != null)

                {

                    de.Dispose();

                }

            }

            return dt;

        }

Code can be downloaded here: Download