I have two machines in an NLB cluster. If I shut-down one machine (to simulate failure) then the second doesn't take-up the load. I'm looking for help in diagnosing the reason for this.
I have built a test/staging system consisting of two network-load-balanced hosts. The hosts are actually VMs running under VMware Server. Each host is running Windows 2003 Server Enterprise with SP2 applied, and each has two NICs. They are newly-built and have minimal config changes apart from installing IIS6.
IP addresses are as follows:
- Host 1: Dedicated: 192.168.0.140 Cluster: 192.168.0.141
Host 2: Dedicated: 192.168.0.142 Cluster: 192.168.0.143
Cluster IP address: 192.168.0.144
Subnet mask: 255.255.255.0
On each host I have set the connection binding order so that the dedicated connection is first.
The cluster is configured to use unicast because I need communication between hosts using the dedicated NICs and I don't have a suitable router for multicast. Host 1 is priority 1, host 2 is priority 2. Weights are set to "Equal".
There is a single port rule:
- All cluster IP addresses
- Port range 80 to 80
- All protocols
- Multiple host filtering with no affinity
There were no problems creating the cluster and it converges ok. I can ping the cluster address, and http requests to that address return the expected result. I do this from a separate machine, always using the ip address.
Problem: When I shut-down host 1 (to simulate host failure) then I would expect host 2 to respond to pings and http requests on the cluster address, but that isn't happening. It looks like host 2 isn't doing anything.
Question: Can anyone suggest how I can troubleshoot this? What am I missing?
I have checked the following:
- IP addresses and subnet masks are set as above. Dedicated connections have gateway and dns addresses specified, cluster connections don't.
- MAC addresses for the cluster NIC are the same on both machines.
- The Cluster connection is bound to the appropriate local IP address and the cluster IP address.
(I'm a developer, not an IT person, so apologies if my terminology is wrong or inexact)