I am currently working in an Exchange 2007 Environment which is quite basic - an EdgeSync Server and an CASHUB. Both of which have two NICS, ostensibly for an internal and external interface in the case of the Edgesync server and for the CASHUB to provide a specific ActiveSync/OWA instance to a less trusted subnet.
The Edgesync server works ok with two NICS, provided they are both in the same subnet (the case during initial configuration). However, once the VLAN is set to provide access only to the appropriate subnet and the ip configuration has been updated mail flow stops.
As soon as the second NIC is activated on the CASHUB client connectivity dies, mail flow stops and OWA cannot access exchange.
It seems to be the case of Exchange/Windows deciding to respond/use the second Interface for tasks which start on the first interface and then because of firewall rules having this blocked.
Is there a way to restrict which services exchange sets to which interface? While I might fix the issue of using the wrong NIC with the routing tables, is there a way to prevent client access from being available over the second NIC?