[ExchangeList] Re: is using site link cost a good idea

  • From: Praveen Ramaswamy <ramaswamy_praveen@xxxxxxxxx>
  • To: exchangelist@xxxxxxxxxxxxx
  • Date: Mon, 11 Aug 2008 10:31:04 -0700 (PDT)

Thanks Michael for your inputs, i will try explore more about the possibilities you have mentioned below.
Regarding HT AD communication. I have two child domain separated by firewall. There is already communication between DCs of these two domains, but still i have to open ports from HT to AD of the other child domain. Not sure if this really required but mail flow started working only after opening port 88 & 389. In fact MS consultant asked me to open only port 25 b/w HT but it did not work and then he asked me to open 88 and 389 from HT to AD of other child domain, then it started working. 
Praveen R 
--- On Mon, 8/11/08, Michael B. Smith <michael@xxxxxxxxxxxxxxxxxxxxxxxx> wrote:
From: Michael B. Smith <michael@xxxxxxxxxxxxxxxxxxxxxxxx>
Subject: [ExchangeList] Re: is using site link cost a good idea
To: exchangelist@xxxxxxxxxxxxx
Date: Monday, August 11, 2008, 9:50 PM

The primary reason RGCs were removed is that it’s duplicate code. The AD KCC and ISTG were developed from Exchange’s link-state code.


You can completely duplicate your RGC setup with AD sites. You have the capability to set exchange-specific site costs and you have the capability of defining a specific HT(s) as a bridgehead server to allow you to completely specify your mailflow. You don’t need to involve the AD team. Now, as bandwidth is a shared resource between AD and Exchange – you probably should. And you probably should be involving them in those discussions with Exchange 2003.


The only reason you might need to involve the AD team is if you need a site that doesn’t already exist, but is instead being covered by another site.


Your HT has to talk to AD anyway, to know what mailbox server hosts a mailbox. Saying that it is because of site routing is specious.


If you couldn’t find a mail-flow issue, even when working with PSS, you should have requested escalation.




Michael B. Smith




From: exchangelist-bounce@xxxxxxxxxxxxx [mailto:exchangelist-bounce@xxxxxxxxxxxxx] On Behalf Of Praveen Ramaswamy
Sent: Monday, August 11, 2008 10:21 AM
To: exchangelist@xxxxxxxxxxxxx
Subject: [ExchangeList] is using site link cost a good idea



I want to know how many of you think that exchange 2007 using AD site link to decide the route is a good idea and why do you think so!


I think it is NOT a good idea! Following are the reasons for thinking so:


·         I love exchange 2003, we have quite a big setup and exchange 2003 runs rock solid. More importantly for 99% of the problems we could find root cause.

·         Need to open additional ports through firewall for HT / AD server communications (We have e2k7 sites across firewall due to business reasons).

·         Mail flow troubleshooting is more complicated than just trying “telnet port 25”. We had two mail flow incidents but we could not find root cause even after working with MS PSS team.

·         Most of the big setups will have windows and messaging verticals as separate verticals, even Microsoft recommends the same, given this we need to request windows team for any route modification, also if they modify AD site cost for any reasons without telling us then it will effect mail flow.

·         Trouble shooting can be lot more complicated as we need check authentication with AD in a particular site and also AD site links.

·         Customizing the mail path is not straight forward . At least MS consultant keeps telling me that e2k7 first tries direct connection then checks AD site cost, but never tells how to make e2k7 not to try direct connection and always force it to use a specific path. Is there a solution to this?? I need this to avoid using low end HT server for mail exchange just because it near to the destination, I want mail to flow through other path on which we have high end server, though It increases 1 hop.

·         I don’t see any major benefit in using AD site link cost over RGC cost


I am not an expert on e2k7 hence I am writing this mail thinking someone might prove me wrong by giving some valid reasons. I eagerly waiting to read some interesting inputs.



Praveen R


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