Microsoft KB Archive/292293

= XCON: @ Disappears When Exchange 2000 Recalculates Routing in Mixed Mode =

Article ID: 292293

Article Last Modified on 2/27/2007

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APPLIES TO


 * Microsoft Exchange 2000 Server Standard Edition

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This article was previously published under Q292293





SYMPTOMS
In a mixed Exchange Server 5.5 and Exchange 2000 Server site with the Internet Mail Service installed on the Exchange Server 5.5 computers, if Exchange 2000 is set as the routing calculation (Recalc) server, any at signs (@) that you enter in the Internet Mail Service address spaces on the connectors may disappear from the routing table after Exchange 2000 recalculates routing.

More specifically, after Exchange 2000 recalculates routing, the routing table in the Site Addressing object on the Exchange Server 5.5 computers no longer reflects routes that contain @. All of the *@ .com routes are displayed as * .com, without @. If you check the address spaces on all of the Internet Mail Services, the address spaces are correct (*@ .com).

If Exchange 2000 is set as a Recalc server in a mixed site and the site contains Internet Mail Service servers, routing may not work correctly. Messages may be sent all over the organization, messages may loop, and messages may even generate non-delivery reports (NDRs).



CAUSE
This problem can occur if an Exchange 2000 server is selected in the Routing Calculation Server box on the General tab in the Site Addressing Properties dialog box.

When Exchange 2000 reads connector information, Exchange 2000 discards everything up to and including @, so that Exchange 2000 is left with only the domain. Exchange 2000 matches the addresses so that Exchange 2000 has the same semantics, but when Exchange 2000 writes to the Gateway Address Resolution Table (GWART), this causes problems with Exchange Server 5.5 routing.



RESOLUTION
To resolve this problem, in the Exchange Server 5.5 Exchange Server Administrator program, select an Exchange Server 5.5 computer as the routing calculation server, and then recalculate the routing. Microsoft recommends that you make sure that an Exchange Server 5.5 computer is your Recalc server until you upgrade all of the Internet Mail Service servers to Exchange 2000.



STATUS
Microsoft has confirmed that this is a problem in Microsoft Exchange 2000 Server.



MORE INFORMATION
In a mixed-mode site, use Exchange Server 5.5 computers to generate GWARTs if at all possible. The GWART generation code is very complicated. In most topologies, you can use an Exchange 2000 server to generate GWARTs without any problems, but it is safer to use Exchange Server 5.5 to generate GWARTs. Exchange Server 5.5 needs the route to be precisely *@microsoft.com, not *microsoft.com, as the route is written to GWART. For example, the route *microsoft.com matches ilikemicrosoft.com, as well as all of the subdomains of &quot;microsoft,&quot; which is not the way that the configuration is designed to work.

Additional query words: ims

Keywords: kbbug kbnofix KB292293

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