[Dovecot] Multiple LDAP authentication servers

[Romer Ventura]

Hello,

 

We are performing a Domain migration and I was wondering if there was any
way to get Dovecot to authenticate to more than 1 LDAP server? Currently
dovecot is configure to query the "mail" attribute from Active Directory and
when found it binds with the credentials the user provided.

 

This works fine, but when migrating user accounts, they get disabled in the
source domain so that the user can no longer log on to it. But disabling the
account in the source domain, causes the user to be unable to use his email
account. 

 

Is there any way to get dovecot to try a second LDAP server if the first one
fails to authenticate..?

 

~# dovecot -n

# 1.2.11: /etc/dovecot/dovecot.conf

# OS: Linux 2.6.29-xs5.5.0.15 i686 Debian 5.0.4 ext3

log_timestamp: %Y-%m-%d %H:%M:%S

protocols: imaps imap

ssl_cert_file: /etc/ssl/certs/smtpd.crt

ssl_key_file: /etc/ssl/private/smtpd.key

login_dir: /var/run/dovecot/login

login_executable: /usr/lib/dovecot/imap-login

login_user: postfix

mail_privileged_group: mail

mail_uid: vmail

mail_gid: vmail

mail_location: maildir:/srv/mail/vmail/%Ud/%Ln/Maildir

mbox_write_locks: fcntl dotlock

imap_client_workarounds: delay-newmail outlook-idle netscape-eoh

lda:

  postmaster_address: postmaster at h-st.com

  auth_socket_path: /var/run/dovecot/auth-master

  log_path: /var/log/dovecot-deliver.log

  info_log_path: /var/log/dovecot-deliver-info.log

auth default:

  mechanisms: plain login

  passdb:

    driver: ldap

    args: /etc/dovecot/dovecot-ldap.conf

  userdb:

    driver: ldap

    args: /etc/dovecot/dovecot-ldap.conf

  socket:

    type: listen

    client:

      path: /var/spool/postfix/private/auth-client

      mode: 432

      user: postfix

      group: postfix

    master:

      path: /var/run/dovecot/auth-master

      mode: 384

      user: vmail

      group: vmail

 

Thanks

--------

Romer Ventura