Replication to Import Computers in a WAN Environment

• Microsoft Windows NT Workstation version 3.5 and 3.51
• Microsoft Windows NT Server version 3.5 and 3.51
• Microsoft Windows NT Server version 4.0

SUMMARY

This article discusses directory replication to a domain name in a Wide Area Network (WAN) environment, why import computers located across a router or bridge may not receive notification, and the procedures for configuring these computers to receive replicated data.

MORE INFORMATION

Page 459 of the Windows NT "Server System Guide" (in the Managing Directory Replication section) states that replication to a domain name does not always succeed when some or all of the replication import computers are located across a wide area network (WAN) bridge from an export server. When adding names to the export list on an export server, and when adding names to the import list on an import computer, for those computers separated by a WAN bridge you should specify the computer names (instead of or in addition to specifying the domain name).

The details of why this is documented and how replication works in this situation are as follows:

When the option to export directories is chosen, and no entries exist in the "To List", the export server defaults to exporting to the local domain. From the export server, mailslots addressed to "\MAILSLOT\NET\REPL_CLI" are broadcast to a multicast address, and if in a TCP/IP environment, a broadcast is sent to the subnet on which the export server resides. Included in the Server Message Block (SMB) is the name of the domain the export server is broadcasting for. An import computer listening for this broadcast responds and sets up a replication session if the import computers domain name equals that of the destination domain name included in the packet. However, import computers that are configured to import from the domain, but are across routers or bridges from where these broadcasts are not forwarded do not receive notification from the export server, and do not receive replicated data.

To replicate directories to import computers across the router or bridge, add the NetBIOS name of the computer to the "To List" on the export server. When the replication interval occurs, the NetBIOS name is resolved and a mailslot addressed to "\MAILSLOT\NET\REPL_CLI" is directed at the import computer specified.