Please mark the reply as an answer if you find it is helpful :-) Once the mailboxes and public folders are migrated to Exchange 2013, then as part of the decommission process, windows NLB can be removed. Make sure to enable the OA on Exchange 2007 for the proxy/redirection to happen from Exchange 2013 to Exchange 2007 mailboxes for the client connectivity. So, it will be a coexistence with all the traffic hitting the Exchange 2013.Įxchange 2007 to updated to the supported version for the coexistence with Exchange 2013. Move the DNS and IP to the new Exchange 2013 servers/VIP in hardware load balancer. Just to iterate, new exchange 2013 server will be setup behind the hardware load balancer. To my knowledge, Yes this is will be better approach and there shouldn't be any issues. So my plan is to move all mailboxes+public folder to Exchange 2013 and take over the Windows NLB IP to the new hardware load balance when we decommission the Exchange 2007.

My question: do you foresee any issue if we still not touch Windows NLB at Exchange 2007 and use the new hardware load balance on Exchange 2013? Since the customer only has limited hardware, we will use half of the server that becomes Exchange 2016 as an interim solution to host Exchange 2013 and we need to replace Windows NLB with the hardware load balance. This Exchange 2007 (CCR+SCR to DR) is using Windows 2003 with Microsoft NLB and I know both already EOL, but we still need to migrate them to Exchange 2016/2019 Mailboxes to Exchange 2013 (all exchange roles on the same box) then another move to Exchange 2016/2019 (all exchange roles on the same box).

As my understanding there no direct path to migrate Exchange 2007 to the newer version Exchange 2016/2019 without any paid tools.

Exchange 2007 outlook 2019