LDAP Connection String from the domain

I am not sure if this is the right forum for this but I am having an issue which is related to Active Directory. I have a SharePoint site where I am utilizing LDAP Connection strings for FBA configuration.

When I specify the AD(Domain1) server as "Server1.Domain1.com" in the string it works but if I just point it to the "Domain1.com" it doesn't works. Also the sharepoint server is part of a different domain(Domain2) than the AD referred above.

But if i just use "Domain2.com" in the connection string (server is part of domain2) it works.

/* Working Scenario */<add connectionString="LDAP://Server1.Domain1.com/DC=Domain1,DC=com" name="ADConnString" />

/* Non-Working Scenario */
<add connectionString="LDAP://Domain1.com/DC=Domain1,DC=com" name="ADConnString" />

Also, if i ping either server1.domain1.com or domain1.com I recieve a reply from the same IP.

Any help will be appreciated.

Thanks

Rahul Gupta

Rahul Gupta, MCITP, MCPD - SharePoint 2010