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Lotus Domino cluster / MS outlook

I clustered my domino server using the application clustering. But some of the users are using MS Outlook to send and receive mails using the domino server using the POP3. But when the fail over happens outlook users need to change the IP address of the POP3 and SMTP server in order to connect to the backup domino server in the cluster. Is there any the fail over can be transparent to the user I mean the outlook users can still use same IP for connecting to the backup domino sever,
3 Solutions
when the servers are registered there is no need to change the IP,, especially in cluster environment user will have no idea whether server got down or not,, because another server will support it...
This problem can be solved by implementing round-robin scheduling in the DNS.
Here's a link to a TCP/IP Knowledge base article that explains how DNS works and how round-robin can work. Speak to your network guys if you need more explanation.


In simple terms you would define multiple IP addresses to a single server name. Instead of having Outlook configured with a fixed IP address configure it to use a Name, e.g. pop3 server.domain.com.

In the DNS records you define pop3server.domain.com to have multiple IP addresses, i.e. the IP addresses of the physical servers. So Outlook can connect to both servers, Domino clustering should keep both servers in sync.

Good luck,
Correct me if I'm wrong but round-robin DNS fails when Domino is down but the OS that hosts Domino is still up, right?  In that case, the Outlook client continues to connect to a server even if Domino is down on that server but obviously POP fails.

A solution that would always work would be a network load balancer appliance, such as http://www.barracudanetworks.com/ns/products/balancer_overview.php

These devices check for a test response from the service you're interested in (POP in this case) and redirect to the other server if the first doesn't provide the expected POP response.  This works even when the OS of the first server is still up.
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