I'm having a rather strange issue with one of our Windows 2008 R2/Exchange 2010 SP2 servers. The machine in questions is a Hyper-V guest with 3 NICs assigned: CAS &HUBManagementReplication The Management and Replication NICs do not have default gateways assigned (DG is 192.168.10.254). The CAS & HUB and Management NICs are on the the same subnet, Replication is different: CAS & HUB (192.168.10.30/24)Management (192.168.10.31/24)Replication (192.168.11.1/24) I want to ensure that all traffic destined for 192.168.12.0/24 routes via the Replication NIC as that will be on our DAG network. I've added a static route using: route add 192.168.12.0 MASK 255.255.255.0 192.168.11.254 IF 15 -p This has resulted in the routing table: When I try a ping from this server to 192.168.12.1 it uses the 192.168.10.30 interface. Extract from firewall: 2012-05-30 10:07:00 Deny 192.168.10.30 192.168.12.1 icmp Any ideas what's going on here?