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Excahnge 2003 Bridgehead question/help


I was hoping that someone here could help us with an issue that were having.

My Exchange environment consists of 4 Local Exchange Servers. Exchange Servers A, B, C and D for ease of explanation. Currently we have Exchange server A set up as a Bridgehead connected to a Smarthost which is also local to the network that Exchange Servers A, B, C and D are on. We are trying to set up redundancy for mail routing should Server A go down. Presently, we have the 2nd Bridgehead server located "offsite"- lets call that Server E. We also have a 2nd smarthost to which Exchange Server E is connected to. The connection between sites is very Fast and reliable so there should be no "slow-link" issues here.

What i've done:
Created a second SMTP Connector identical to the 1st except that i have increased the cost on the 2nd connector to "2" and obviously added Server E in as the "Bridgehead" on this connector- per this article http://technet.microsoft.com/en-us/library/bb124455(EXCHG.65).aspx.

With this set up as is- mail successfully flows through either connector (provided i adjust cost manually to effectively force it) but doesnt "fail-over" like we need it to.

To test this i have tried "freezing" the queue and physically disconnecting Server A from the LAN.

If i "freeze" the SMTP connector, rather than failing over the mail just queues. I have to manually adjust the cost on Server E to a lower cost than that of Server A to allow for mail-flow.

If i "disconnect" Server A from the LAN the mail queues on Server(s) B C and D regardless of the cost on Server E's routing connector.

the only other thing that i can see is that in the list of servers under the "Members" folder- Server A shows up as the Master and the rest of the servers show up as Members.

Hopefully one of you guys have seen this before and can help out!!

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1 Solution
Costs of 1 and 2 are wayy too close.  Make the secondary connector something like 20 or 50 and the primary connector a cost of 1.
Which server is the Routing Group Master; is it Server A?
  Don't arbitrarily change this because of the failure of the bridgehead.  This can create link state problems (you can view these in winroute and fix them with remonitor)

Chances are you are seeing the messages queue up because of link state traffic not recognizing that Server A is down.  The remote system will not start routing the messages until it believes that Server A, the bridgehead for the SMTP connector with * and a cost of 1 is actually down.

AGCITAuthor Commented:
Yes, Server A is the Master. So you're saying that i should change the cost to a high number on the "failover" server to something like 50?. At that point, when the mail queue's on Server A as it has in the past how does that mail get routed back over to Server E (failed over scenario)?? I thought i read somewhere that once mail hits a bridgehead thats where it stays until it becomes available again.

So my scenario is this- Server A (the master and current Bridgehead) completely crashes- how do i make mail route to Server E the secondary Bridgehead- I have already used a cost of 1 and 2, 1 and 3 and 1 and 5 in my attempts to configure- in all instances mail ends up queueing on the servers that arent bridgeheads (Servers B, C and D)??

Let me try and get a bigger picture
   First Adminstrative Group
      Routing Group One
         Server A (Exchange FrontEnd; Routing Group Master
         Server B (Exchange BackEnd; Mailbox Server or MB and Public Folder Server)
         Server C (Exchange BE; MB and/or PF Server)
         Server D (Exchange BE; MB and/or PF Server)
       SMTP Connector One (Local Bridgehead; Server A; * Address Space; Cost: 1; Scope: Entire Org)

      Routing Group Two
         Server E (Exchange FrontEnd; Routing Group Master; mailbagging outbound mail)
               SMTP Connector One (Local Bridgehead; Server A; * Address Space; Cost: 1; Scope: Entire Org   (--Recommend raising the cost to 40 or 50)

What it appers that you need is a Routing Group Connector between Routing Group One and Routing Group Two with A and E designated as the appropriate bridgehead servers.  Without this in place then B, C, and D do not have a route to Server E.

Caveat -
If E is part of Routing Group One then why not just add it to the SMTP connector and let Exchange make the choice of which server to leverage using a higher MX for E's DNS A record on the external DNS   servers so that remote systems don't use it unless A is down? This makes things a little simpler in the fact that you know E works and you don't have to scramble to fix A records, PTR records, SPF records and possibly MX records that were missing since A was functioning properly.



AGCITAuthor Commented:

We are planning some downtime later this week to work on the issue. The way we have it set up is that all the exchange servers are in the same Routing Group. Im going to change the Routing Group Master from server A to Server E and set the cost on server E to 10. If that doesnt work, i will give your "caveat" solution a shot.

thanks for your help!

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