PMDF System Manager's Guide

By definition, centralized naming is only useful if it is consistently used. This in turn means that the flow of messages within the organization may need to be altered or controlled to insure that the proper name translations are applied at the proper times.

In many cases this happens automatically. For example, suppose PMDF is serving both as a centralized naming authority and as the only gateway between the Internet, a cc:Mail postoffice and an ALL-IN-1 installation. In this situation any message travelling between systems has to flow through PMDF and name translations will always be applied.

However, things are not always so simple. Suppose that PMDF is acting as a centralized naming authority for several hundred UNIX workstations, all using SMTP based mail and all with direct Internet access. In this situation messages are likely to escape to the Internet without passing through PMDF and hence without having proper name translations done.

There are two ways to solve this problem. One is to adjust message routing to force all messages to pass through the central naming authority. The other is to distribute the centralized naming functionality, in effect making all the systems into central naming authorities. A combination approach is also possible, where a number of systems act as centralized naming authorities and other systems route mail through an appropriate authority.