On 9/25/2012 12:33 PM, Aaron Bennett wrote: > -----Original Message----- > From: owner-postfix-us...@postfix.org > [mailto:owner-postfix-us...@postfix.org] On Behalf Of Ralf Hildebrandt > Sent: Tuesday, September 25, 2012 9:30 AM > To: postfix-users@postfix.org > Subject: Re: sporadic bouts of lost connections to exchange 2010 hub transport > > * Mikael Bak <m...@inbox.lv>: >> Hi Stan, >> >> On 09/25/2012 08:22 AM, Stan Hoeppner wrote: >>> >>> Apparently Linux and Windows TCP window scaling doesn't always work >>> reliably together. Try disabling TCP window scaling on the Linux box(en): >>> >> [snip] >> >> Perhaps off topic, but do you have any links to documents or similar >> that proves that there is a problem between the two operationg systems >> with regard to TCP window scaling. This is the first time I hear about >> this to be honest. > > > I don't know if this is useful, but in our situation the exchange "server" is > actually two boxes with both the CAS and Hub Transport roles on them bound > together via the software-based windows Network Load Balancer. Since we > never had issues relaying to our Exchange 2007 environment (which was based > on 2K3 not 2K8), I suspect that the NLB may be the cause. I'm going to > disable window scaling on one of our three relays and see if it crops up > again on the other two. > > Thanks, >
Regardless if this fixes your problem or not, it's wise to implement the fixes detailed in http://www.postfix.org/QSHAPE_README.html#backlog so that any brief hiccup in delivery doesn't turn into a ~20 minute service interruption. -- Noel Jones
