I recently upgraded samba on a domain controller from samba3-3.3.4-39.el5 to samba3-3.3.6-39.el5 (from SerNET on a CentOS 5.3 box), and the interdomain trusts between the samba domain and my AD domain quit working. The /var/log/samba/wb-ADDOMAIN file was full of this message: [2009/07/02 09:19:57, 0] libads/kerberos.c:ads_kinit_password(362) kerberos_kinit_password SAMBADOMAIN@ADDOMAIN.UNIVERSITY.EDU failed: Cannot find KDC for requested realm Even though the Samba-HowTo says that configuring your krb5.conf file may be detrimental, I did so anyway. After configuring my krb5.conf, winbind was able to resolve users from the AD domain.