How to properly configure NLB cluster in Windows 2008

Hi,
 
I have just tried to configure 2 node Windows 2008 NLB cluster and I run into problem.
Until now I have successfully installed Windows Server 2003 NLB clusters. I used 2 nic per node and unicast mode.

For example

    Node1                                                        Node2
                Pub Interface (default)                                Pub Interface (default)
                        IP:192.168.1.11/24                                    IP:192.168.1.12/24
                        GW: 192.168.1.1                                        GW: 192.168.1.1


                NLB Interface*                                                 NLB Interface*
                        IP:192.168.1.12/24                                    IP: 192.168.1.13/24
                        GW:-                                                           GW:-

*DNS registration, File Share client and server, NetBIOS over TCP/IP disabled on this interface.

After configuring IP addresses I would run NLB manager and configure cluster in unicast mode.


When I tried this on Windows Server 2008, I could not access NLB address outside local subnet. Only when I configure DEFAULT GATEWAY on both NIC's, NLB started working.

When I run network monitor I notices that in this configuration, Windows 2003 would always respond using Public LAN (source MAC address would be from public NIC), no matter if i tried to connect to Public or NLB IP address.

In Windows 2008 if I tried to connect to Public IP, response packet would had source MAC address from Public NIC and when I accessed NLB address then source MAC would be from NLB NIC. For me this looks like change from 2003.

So how do we correctly configure unicast NLB cluster with 2 NIC's in Windows Server 2008? Do we just add default gateway to NLB NIC?


Krunoslav

P.S.
When I tried to search for solution I found that other people had this issue.