Here's an article about changing the negative caching: http://windowsitpro.com/article/articleid/48528/controlling-positive-and-negative-caching.html
Jeff On Wed, Apr 29, 2009 at 7:25 PM, Charlie Kaiser <[email protected]>wrote: > I'm running into a problem at one of our clients. W2K3 AD, running E2K3. > When SMTP mail goes out, we're seeing DNS problems that result in NDRs. > This > type of problem has been documented here: > > http://social.technet.microsoft.com/forums/en-US/exchangesvrtransport/thread > /178b88bb-bbdb-4cc2-896b-711fdeeb36d8/<http://social.technet.microsoft.com/forums/en-US/exchangesvrtransport/thread%0A/178b88bb-bbdb-4cc2-896b-711fdeeb36d8/> > > Bottom line is that DNS lookups are failing, and mail is going to the A > record for the remote domain instead of the MX record. Apparently this is > by > design with E2K3/W2K3 when a negative reply comes back. > > What I'm trying to find out is this: Is there a way to prevent server-side > caching of negative replies to remote DNS queries? Or at least reduce their > life to a few seconds? I've seen articles that show how to do it for the > client side, but that doesn't affect the DNS server cache. > > We're using ISP forwarders (ATT). I think there may be a firewall > (watchguard) or other external issue causing the DNS lookup failures. I'm > trying to get the client to authorize that kind of troubleshooting, but in > the meantime, we're looking for a fix from another angle. Right now, I've > created an AT job to clear the DNS server cache every 5 minutes. That's an > ugly workaround, but when the CEO gets NDRs, you get creative. :-) > > Any ideas? > > Thanks... > > *********************** > Charlie Kaiser > [email protected] > Kingman, AZ > *********************** > > > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ > ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ > ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
