A great tool to help figure out the mtu issues is mturoute. It can be found here:
http://www.elifulkerson.com and some tips about using it here: http://blog.ioshints.info/search?q=mturoute The Mxtoolbox is pretty great, but caveat with their new beta all-in-one tool. At least as of last week it seems to have some bugletts specifically with dns reverse lookups. Sounds like I should be glad we're not outsourcing Exchange (yet!). ~JasonG > -----Original Message----- > From: KevinM [mailto:kev...@wlkmmas.org] > Sent: Friday, March 25, 2011 14:41 > To: MS-Exchange Admin Issues > Subject: RE: Mitigating outsourced Exchange performance > > David, In addition to the stuff I sent you offline. > > > > Some fire walls will add too much overhead to a packet and make it larger > then Exchange will accept. Exchange2007 (BPOS) only accepts packets that > are 1492 in size or smaller. Windows has a default MTU of 1500 so windows > to Exchange is normally fine. Toss a Firewall in there doing magic, or > maybe a VPN and you can go over the 1492 size limit. This can lead to > packets being dropped, and or becoming fragmented and stuff. I saw a lot of > Juniper Firewalls do this and MAC clients did this because they don't have > the MTU setting like Windows does. > > > > The recommendation was to set the MTU on the Firewall to 1500 or the MAC to > 1492, of course this should be tested and such. This can help with items > stuck in the outbox. > > > > As for it taking 2 minutes to get emails you really need to look at the > headers. www.Mxtoolbox.com has a great header analyzer you can copy and > paste the headers into to very quickly see where the message delays are > coming from. > > > > Cheers > > Kevinm > > Ex-BPOS Senior Support Engineer - Happily consulting for myself again. > > > > From: David Lum [mailto:david....@nwea.org] > Sent: Friday, March 25, 2011 9:37 AM > To: MS-Exchange Admin Issues > Subject: Mitigating outsourced Exchange performance > > > > We recently outsourced Exchange (we're at 400+ users) and are adjusting to > the responsiveness difference. For those that have outsourced, what kinds > of things have you guys done to improve the performance? In our main office > of ~250 employees we have 75+MBps download/upload speed (yes we're blessed > with a big pipe). > > > > Issues reported: > > 1) Big lags (45 seconds+ ) on loading others' calendars to view, > especially if scheduling a meeting with 5+ others > > 2) E-mail sits in the outbox for minutes > > 3) Minutes for an e-mail to come in > > > > The joyous part is it's not 100% across-the-board like this for everyone. > I'm working on narrowing down if there's a common theme of thousands of > messages in their inbox, dozens of inbox folders, etc. I found this LINK > <http://blogs.technet.com/b/exchange/archive/2007/12/17/3404552.aspx> > which looks helpful but would like to hear your guys' opinions as well. > > > > TIA, > David Lum // SYSTEMS ENGINEER > NORTHWEST EVALUATION ASSOCIATION > (Desk) 503.548.5229 // (Cell) 503.267.9764 > > > > > > --- > To manage subscriptions click here: http://lyris.sunbelt- > software.com/read/my_forums/ > or send an email to listmana...@lyris.sunbeltsoftware.com > with the body: unsubscribe exchangelist > > --- > To manage subscriptions click here: http://lyris.sunbelt- > software.com/read/my_forums/ > or send an email to listmana...@lyris.sunbeltsoftware.com > with the body: unsubscribe exchangelist --- To manage subscriptions click here: http://lyris.sunbelt-software.com/read/my_forums/ or send an email to listmana...@lyris.sunbeltsoftware.com with the body: unsubscribe exchangelist
