• RSS
  • Twitter
  • FaceBook

Exchange Server Forums

Forums | Register | Login | My Profile | Inbox | RSS RSS icon | My Subscription | My Forums | Address Book | Member List | Search | FAQ | Ticket List | Log Out

Automatic Redundant Routing in Exchange 2007

Users viewing this topic: none

Logged in as: Guest
  Printable Version
All Forums >> [Microsoft Exchange 2007] >> Message Routing >> Automatic Redundant Routing in Exchange 2007 Page: [1]
Login
Message << Older Topic   Newer Topic >>
Automatic Redundant Routing in Exchange 2007 - 5.Oct.2008 7:56:51 PM   
ponzekap2

 

Posts: 135
Joined: 21.Aug.2007
Status: offline
At my company we have two AD sites, and I have configured our Exchange 2003 routing topology to mimic this setup.  We have also two non-exchange SMTP gateway servers at each site, that all outgoing email flows out of.  Our current setup is we have SMTP connectors in each routing group, that have an address space of * and a cost of 5, that route all mail through their respective gateway servers, in their site. 

To create a redundant enviornment, I have also created another SMTP connector in each routing group, with a cost of 7, that routes email from Site A, out through the gateway server in site B, in case of a server failure in Site A, or loss of internet connection.  This allows outgoing email to automatically start flowing out to remote site, so that there is virtually no downtime for outgoing emails.  This works great for us.

I have begun designing our Exchange 2007 migration, and in my tests, it seems that the same setup with multiple send connectors does not work in Exchange 2007.  From reading Microsofts documentation, it seems that this is by design.  Exchange 2007 does not use link status updates, so it will not re-calculate a route if a server is down, so essentially admin interference is neccessary.  I know that I can create a send connector, and specify both of the gateway servers as smart hosts, and this will work, but I also dont want this to be used in a round robin approach.

What is the best way, and what have you guys used, to create the above enviornment in Exchange 2007.  Essentially each site will have one hub transport and one mailbox role installed.  Each site will have its own dedicated non-exchange smtp gateway server.  If the gateway server in site A fails, how do i get email to route out through the gateway server in site B, besides adding this as a second smart host in the send connector?

Sorry for the lenghty post.
Post #: 1
RE: Automatic Redundant Routing in Exchange 2007 - 6.Oct.2008 8:12:52 PM   
josh

 

Posts: 190
Joined: 1.Oct.2008
Status: offline
http://www.msexchange.org/articles_tutorials/exchange-server-2007/planning-architecture/load-balancing-exchange-2007-sp1-hub-transport-servers-windows-network-load-balancing-technology-part1.html

http://www.msexchange.org/articles_tutorials/exchange-server-2007/planning-architecture/load-balancing-exchange-2007-sp1-hub-transport-servers-windows-network-load-balancing-technology-part2.html

(in reply to ponzekap2)
Post #: 2
RE: Automatic Redundant Routing in Exchange 2007 - 6.Oct.2008 8:16:01 PM   
ponzekap2

 

Posts: 135
Joined: 21.Aug.2007
Status: offline
Josh,

Thanks for the reply, but thats not what I want.  I am not worried about NLB the hub transport servers, but instead want to configure redundant routing topology for External email.

So if the gateway email server in NY site goes down, external email will flow from NY out to the London gateway server.

(in reply to josh)
Post #: 3
RE: Automatic Redundant Routing in Exchange 2007 - 6.Oct.2008 8:22:07 PM   
Elan Shudnow

 

Posts: 897
Joined: 4.Jan.2007
From: Chicago, IL
Status: offline
Something like the following?
Set-SendConnector "Internet Connector to local SMTP Appliance" -AddressSpaces "*;1"
Set-SendConnector "Internet Connector to other site's SMTP Appliance" -AddressSpaces "*;2"

_____________________________

Elan Shudnow
Exchange MVP
http://www.shudnow.net

(in reply to josh)
Post #: 4
RE: Automatic Redundant Routing in Exchange 2007 - 6.Oct.2008 8:24:27 PM   
ponzekap2

 

Posts: 135
Joined: 21.Aug.2007
Status: offline
Yea, but I've tried this.  If the primary connector fails, like the remote smart host is down, it never fails over to the second connector. 

(in reply to Elan Shudnow)
Post #: 5
RE: Automatic Redundant Routing in Exchange 2007 - 6.Oct.2008 8:29:43 PM   
Elan Shudnow

 

Posts: 897
Joined: 4.Jan.2007
From: Chicago, IL
Status: offline
Hm, should work.  I'm assuming you have SP1 and Rollup 3 for SP1 installed?  Have you tried turning up diagnostic logging (Set-EventLogLevel) and maybe it'll give some clues as to why it's not failing over to the next connector?  Or maybe run BPA and it'll elude as to some misconfiguration?

If none of the above really work, it really sounds like a bug otherwise there'd be no point to those costs.  A call to PSS probably would be needed.

_____________________________

Elan Shudnow
Exchange MVP
http://www.shudnow.net

(in reply to ponzekap2)
Post #: 6
RE: Automatic Redundant Routing in Exchange 2007 - 7.Oct.2008 12:04:45 AM   
ponzekap2

 

Posts: 135
Joined: 21.Aug.2007
Status: offline
See, this is the documentation I was referring to.  It seems that this specific type of situation wont allow the message to be re-calculated.

Message delivery failures that are caused by network connectivity problems are not detected by the routing component of the categorizer. When an SMTP connection cannot be established to the next hop target, SMTP Send retries the queue. The MaxIdleTimeBeforeResubmit parameter, which is located in the EdgeTransport.exe.config file, has a default value of 12 hours. After the configurable retry interval (MaxIdleTimeBeforeResubmit) has expired without successfully establishing a connection, all messages from the delivery queue are resubmitted to the Submission queue. If the connectivity problem still exists, this process is repeated. If the connectivity problem is resolved, messages are delivered as soon as message retry is successful. Or, a configuration change that modifies the next hop destination may resolve the problem. For example, if the problem is caused by all the Hub Transport servers in a destination site being offline, and you move mailboxes to a server in a different site, the next hop would change to the new site.
Note: The auto resubmission from the message delivery queue to the Submission queue only happens for non-connector queues. Connector queues remain in retry mode until the problem is fixed, or the messages expire and a non-delivery report (NDR) is sent.

(in reply to Elan Shudnow)
Post #: 7
RE: Automatic Redundant Routing in Exchange 2007 - 7.Oct.2008 2:42:10 AM   
Exchange_Geek

 

Posts: 1287
Joined: 31.Dec.2006
Status: offline
All this sums up to one line - (correct me if i am wrong) Exchange 2007 has removed the concept of link-state update technology which was present in Exchange 2003.

This means that if a connector has been specified to send emails - Exchange WOULD NOT try to send email over any other connector if the specified connector goes down.

We had a concept to re-categorize messages even if messages were stuck for a particular queue in Exchange 2003. This i believe has been removed in Exchange 2007.

So, if we are expecting the redundancy in mail flow by creating second connector for the same RG - this wont work.

(in reply to ponzekap2)
Post #: 8
RE: Automatic Redundant Routing in Exchange 2007 - 7.Oct.2008 9:39:35 AM   
ponzekap2

 

Posts: 135
Joined: 21.Aug.2007
Status: offline
Exactly, which is what I said previously. 

you can always specify the smart host in the same connector, but then you get load balance, which may not be ideal.

(in reply to Exchange_Geek)
Post #: 9

Page:   [1] << Older Topic    Newer Topic >>
All Forums >> [Microsoft Exchange 2007] >> Message Routing >> Automatic Redundant Routing in Exchange 2007 Page: [1]
Jump to:

New Messages No New Messages
Hot Topic w/ New Messages Hot Topic w/o New Messages
Locked w/ New Messages Locked w/o New Messages
 Post New Thread
 Reply to Message
 Post New Poll
 Submit Vote
 Delete My Own Post
 Delete My Own Thread
 Rate Posts


Follow TechGenix on Twitter