Q149121: XCON: Gateway Address Routing Table Information
Article: Q149121
Product(s): Microsoft Exchange
Version(s): 4.0,5.0,5.5
Operating System(s):
Keyword(s): kbusage exc4 exc5 exc55
Last Modified: 22-OCT-2000
-------------------------------------------------------------------------------
The information in this article applies to:
- Microsoft Exchange Server, versions 4.0, 5.0, 5.5
-------------------------------------------------------------------------------
SUMMARY
=======
Each Connector has an associated address space (or spaces) and a Connected Sites
configuration. Both associations can be defined using the Exchange
Administration program and can be replicated by the directory to or from
adjacent sites. As this information is created by configuration and replicated
by the directory, it is used by the System Attendant and the Message Transfer
Agent (MTA) to generate a routing table called the Gateway Address Routing Table
(GWART). Each server maintains its own GWART within its Directory.
The GWART is stored in the ds (on the site Addressing object in the gateway-
routing-tree attribute); the Ems_rid.dll is the module that generates the GWART
and can be called from admin ("Regenerate Routing" button) and MAD (based on the
schedule). Renaming or deleting the GWART text file will have no impact on the
routing information.
MORE INFORMATION
================
In order to successfully deliver a message, the MTA compares the recipient of
the message to the GWART to determine through which group of connectors the
message can be delivered. The final result of the search provides a group of
Connectors which can deliver the message to the remote site.
The GWART is kept by the Directory. It can be viewed by an Administrator using
the Site Addressing Object. The Routing property page displays the routing table
as it has currently been calculated.
Under normal circumstances, the routing table is rebuilt when changes occur
(changes are refreshed very quickly). If you want to force a re- calculation,
click Recalculate Routing. You can view the contents of the GWART by using a
text editor, such as Notepad. The GWART is located in the EXCHSRVR\MTADATA
directory. Each time the routing of a server is updated, the GWART is updated
and a single backup copy is saved for administrative reference only. The
following is a list of the GWART files and its purposes:
Filename Purpose
---------- ----------------------------------
GWART0.MTA Current Routing table text file
GWART1.MTA Routing table prior to last change
Reading The GWART
-----------------
The GWART can be segmented into three major areas. Each area corresponds with an
address type, which Exchange uses to send mail. These address types are as
follows:
Address Type Description
------------ --------------------------------------------
Distinguised Name The native Microsoft Exchange Server address
(DN) format. These are reflected as type EX.
Domain Defined The format used for custom recipient storage
Attribute (DDA) (for example: MS and SMTP).
O/R Address The Native X.400 address type.
Each line of the GWART indicates an available path which the MTA can use to route
messages to a destination.
[ Address Space ] [ cost ] [ connection 1, connection 2, .......]
EX, /O=ORGNAME/OU=Site-X , 2 , Connector to Site-A, Connector to
Site-B
When the MTA makes a routing decision, it scans through the GWART to find an
address space that matches the address of the message. If an available address
space is identified, the MTA routes the message to the associated connector.
Obtaining details on any GWART entry reveals the associated connector in a
Routing Details dialog box.
Sample GWART Diagram
--------------------
For troubleshooting purposes, it is recommended that you view the GWART. You can
save the GWART as a text file, and open it as a text file using a text editor.
The following diagram graphically represents the connections for the sample
GWART listed below:
To the Internet X400 Cloud (GB, Frisco)
| /
| IMC / X400 Connector
| Cost = 1 / Cost = 1
| /
+ SATURN -----------------------+
| |
| SITEz |
+------------------------ PLUTO +
/ |
/ | MS Mail Connector
/ Site Connector | Cost = 1
/ Cost = 1 |
BSD MSNET/PO1
MSNET/PO2
Sample GWART:
EX,/O=WYNNWARE/OU=FRISCO;,1, Connection to Frisco
EX,/O=MICROSOFT/OU=BSD;,1,Site Connector (BSD),
MS,MSNET/PO1;,1,MS Mail Connector (PLUTO),
MS,MSNET/PO2;,1,MS Mail Connector (PLUTO),
SMTP,*;,1,Internet Mail Connector (SATURN),
X400,c=GB;a=TMAILUK;p=*,1,Connection to Frisco,
X400,c=US;a= ;p=MICROSOFT;o=BSD;,1,Site Connector (BSD),
Additional query words:
======================================================================
Keywords : kbusage exc4 exc5 exc55
Technology : kbExchangeSearch kbExchange500 kbExchange550 kbExchange400 kbZNotKeyword2
Version : :4.0,5.0,5.5
Issue type : kbinfo
=============================================================================
THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.
Copyright Microsoft Corporation 1986-2002.