Failover Cluster Service for Exchange 2010 DAG over WAN

Whem running an Exchange 2010 DAG over a WAN, you may run into some of the limitations of Microsoft FCS (Failover Cluster Service). This service defaults to fairly low timeouts for fast failover in LAN environments. In a WAN environment, where latency may be higher, and some packet loss may occur, you may need to tweak the timeouts for FCS. I advise to tweak most of the settings via the FCS admin tool. However, there are a few settings to tweak via the command line, and here are the maximum values you can configure to make it "less sensitive":

 

cluster /prop SameSubnetDelay=2000:DWORD

cluster /prop CrossSubnetDelay=4000:DWORD

cluster /prop CrossSubnetThreshold=10:DWORD

cluster /prop SameSubnetThreshold=10:DWORD