I have just installed ACS 4.2 on two VMware hosts. I've configured database replication but it won't work. The error message is "shared secret mismatch". This error message occurs if a NAT device is in the path (which it isn't in this case) or if the tcp header is otherwise changed during transmission. I'm wondering if VMware is adding something to the TCP header. Has anyone come across this problem before or has anyone successfully implemented ACS replication when both hosts are on VMware?