FROM: TMG Exchange 2010 -> TO: F5 Exch 2010+2016 Coexistence - Poor Performance

Hey DevCentral,

 

we just made the change from Exchange 2010 which was running on old Microsoft Forefront TMG to F5 iApp Exchange 2010 + 2016 with Load Balancing and Access Policy and everything else. It is still kind of "default" configured. I just have extended the Access Policy to make sure all customers from different WAN Locations and different domains can access to OWA etc.

 

Internal everything does work really fine. But external sources (like a Kindergarten want to Access OWA via the Town Hall infrastructure) are running reaaally slow. How can that be? I tried to research the problems.

 

We have:

 

AP OWA: Deployed Exchange 2016 iApp

 

AP Server 1: 2010 LB with 2 Nodes, 2016 LB with 2 Nodes

 

AP Server 2: Virtual Server "Exchange redirect" with SNAT Auto Map (Is necessary for reaching the right network)

 

What I tried:

 

TCP Profile: Disable Nagle Algorithm, Disabled "Delayed Acks", Disabled "Slow Start"

 

SSO: Method is configured as HTTP basic on both side (Exchange + F5).

 

Double checked if domains/ip's are configured correctly (should be 100% fine, because it is running, but slow from external)

 

Would be thankful for any idea! (Screenshots below: TCP Profile AP OWA, LB Virtual Servers AP Server 1)