Server Update/replication

It sounds like a great idea! I assume that each of your 21 servers are already set up to be multi-homed, and that the routing service is correctly configured. In that case, each service needs to be configured to replicate with a particular host, using a particular interface. I haven't tried such a setup, but I really like the idea. The key is getting the Routing Service set up correctly, so that replication/update requests go out over the backdoor network. What needs to be done to make that work is to set all of the servers' secondary interfaces to use a separate subnet from the primary network to which they belong. Then the routing service can be configured to redirect packets appropriately. The individual replication/update services can then be set to use the 'other' network to do their jobs.

This sounds like a fun project, and I'd like to see you post more detail about your setup.

I only have a couple possible ideas to throw out. NIC's can be assigned more than one address. It should be under one of the tabs when you go into the TCP/IP settings. I forget exactly which tab it is so you'd have to poke around a little, but it's pretty obvious once you find it. Secondly, you said you wanted to not tie up network bandwidth with the replications. My instructors always talked about scheduling backups, replications, etc. during off-peak hours (ie at night when everybody's home asleep) when the network usage is going to be at a minimum. It's not much but I hope I brought a couple things up that hadn't been thought of.

Why not just load balance the two Nic's in each server?
Depending upon the switch or NIC's ,this seems to be the easiest way to accomplish what you want to do.

Hi,
Why dont u try giving ip of different class or subnet to second NIC. So that u can join them separately by a different switch.

There is one more option, u forget about second NIC and configure VLAN for that group of ip's. U do the inter VLAN routing config on router. IF it is a layer 3 switch u can do it on switch itself.
So that all the server update related stuff will be separated from actual network. When users want to access server they go by vlan routing. this reduces the network traffic.

this does sound interesting but i have to wonder if it is necessary. have you done any monitoring of the network traffic or the percent of bandwidth being used on the network interfaces? if you are running a fully routed 100 mb network i would not be surprised to see your network interfaces running about 10%. it just seems that the network interface is not a bottleneck any more these days.