“A referral was returned from the server” exception when accessing AD from C#

Question

DirectoryEntry oDE = new DirectoryEntry(\"LDAP://DC=Test1,DC=Test2,DC=gov,DC=lk\");

using (DirectorySearcher ds = new DirectorySearcher(oDE))
{
    ds.PropertiesToL         


        

Answer 1

A referral was returned from the server error usually means that the IP address is not hosted by the domain that is provided on the connection string. For more detail, see this link:

Referral was returned AD Provider

To illustrate the problem, we define two IP addresses hosted on different domains:

IP Address DC Name Notes

172.1.1.10 ozkary.com Production domain

172.1.30.50 ozkaryDev.com Development domain

If we defined a LDAP connection string with this format:

LDAP://172.1.1.10:389/OU=USERS,DC=OZKARYDEV,DC=COM

This will generate the error because the IP is actually on the OZKARY DC not the OZKARYDEV DC. To correct the problem, we would need to use the IP address that is associated to the domain.