Retrospect Backup 7.7 Will Not List Exchange 2007 Mailboxes

Problem: When I went to create a full backup job for the Exchange 2007 server (single server install) thru Retrospect 7.7 I could not "Preview" the mailboxes i.e. ... have Retrospect scan all mailboxes for me and list the contents to be backed up. I received a "error -3408 (Unknown)"

While working with Retrospect Support they found this in-house KB article that basically says an IPv6 Loopback address (::1) in the hosts file causes issues with the Exchange RPCproxy (that Retrospect relies on) communicating with the rest of the Exchange processes. The solution was simple - to create IPv4 addresses in the Hosts file for both the Netbios and FQDN of the Exchange server. See Below.

Solution:

Users with Exchange 2007 on Windows 2008 and Active Directory on a different 2008 Server:
When trying to log into Exchange 2007, Retrospect fails to show the mailbox list, and operation log shows as following when debug log level is set to 6.
T-2: CreateProfileAndSession: ConfigureMsgService(EXCHANGE,=rbu) returned 0x80040115.T-2: TMapiConnection::TMapiConnection: Unable to use profile, win error 0x80040115T-2: TMapiManager::Reinitialize: couldn't intialize mailboxes due to a prior error.Retrospect error code error -3408 (unknown) Cause:
Windows 2008 enables IPv6, however Exchange DSProxy does not listen on IPv6, which leads to failure in profile creation. More info can be found at: http://blogs.msdn.com/stephen_griffin/archive/2008/08/15/mapi-and-ipv6.aspx

RESOLUTION:
Depending on whether RPCRroxy is on the same server as the Mailbox role, there are two cases.

Solution for case 1:
If you're in a single-server configuration with the RPCProxy and Mailbox on the same machine, then the above does not work since the loopback interface still uses IPv6. In this case, you need to make the following changes in the system32\drivers\etc\hosts file:

1. Comment out the line ":::1 localhost"
2. Add the following two lines:
<IPv4 address> <hostname of the computer>
<IPv4 address> <FQDN of the computer>

Solution for case 2:
If you're in a multi-server scenario where the RPCProxy is not on the same server as the Mailbox, then you need to do the following:
1. Unselect IPv6 from the properties of your NIC (on the RPC-over-HTTP Proxy machine); that will force the RPC-over-HTTP Proxy to use IPv4 to talk to Exchange and everything will be fine. In most cases, this step suffices. If it does not, continue with steps 2 and 3.
2. Under the regkey HKLM\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters, add a 32 bit DWORD with the name DisabledComponents and value 0x000000FF
3. Reboot the machine.