XFOR: IMC Unable to Resolve Host Addr. Using Raptor Firewall

• Microsoft Exchange Server, version 4.0

SYMPTOMS

When using Raptor Firewall DNS proxy caching, and trying to send mail to a host where the Mail domain is the same as the Address Record domain, the IMC cannot resolve the Fully Qualified Domain Name (FQDN) to an IP address. For example, the Address (A) record and Mail Exchanger (MX) record in the DNS may look like the following:

   microsoft.com.  IN  A  123.123.123.123
   microsoft.com.  IN  MX  10  microsoft.com. 

CAUSE

The IMC buffer that holds the DNS response incorrectly assesses the end of the buffer. If there are no additional resource records, this causes the IMC to fail during host resolution.

WORKAROUND

Change the mail domain so that it is different from the mail exchanger host. This means the SMTP address used by your Microsoft Exchange Server users will also change.

STATUS

Microsoft has confirmed this to be a problem in Microsoft Exchange Server version 4.0. This problem was corrected in the latest Microsoft Exchange 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

S E R V P A C K

Additional query words:

Keywords : kbusage kbbug4.00 kbfix4.00.sp4 XFOR
Version : winnt:4.0
Platform : winnt
Issue type : kbbug