This section discusses the following additional network services that you can use to further increase the availability of your network:
Consider setting up primary and secondary servers according to RFC2182.
Email dispatch is the most important aspect to consider. You can set up a separate mail host, for which the addressing is controlled using a corresponding Mail Exchange (MX) record.
You can use primary and secondary domain controllers in a Windows NT domain.
For example, you can use a server with Lightweight Directory Access Protocol (LDAP). You can either replicate LDAP servers (for example, using zone replicas) or protect them against failure with cluster solutions.