Load balanced web server

I am trying to set up a load balanced web farm. Here is the issue:
I have a server with 2 NIC's one that runs through the load balancer
(192.168.1.xxx) and one that doesn't (172.16.xxx.xxx). I have been unable to
figure out haow to make traffic that comes in on one NIC go back out on the
same. The only thing I have been able to do is send either all or none of
the traffic through the load balancer. Each NIC having it's own gateway
doesn't work. Any help would be greatly appreciated.

"Alan_S" <(E-Mail Removed)> wrote in message
news:32201E91-683D-4A52-A06F-(E-Mail Removed)...
> I am trying to set up a load balanced web farm. Here is the issue:
> I have a server with 2 NIC's one that runs through the load balancer

Run *one* Nic in each machine.
Use Server Clustering.
The "Cluster" will have a "Virtual IP" that is used instead of the actual
literal IP#s of the Nucs.

> (192.168.1.xxx) and one that doesn't (172.16.xxx.xxx). I have been unable
to
> figure out haow to make traffic that comes in on one NIC go back out on
the
> same.

You can't. There is no direct relationship between an incomming session
(incomming packets) and an outgoing session (outgoing packets). Each
involves a separate "routing decision" and the "decision" is dsitinct and
independent from the other.

> The only thing I have been able to do is send either all or none of
> the traffic through the load balancer. Each NIC having it's own gateway
> doesn't work. Any help would be greatly appreciated.

You can only have one Default Gateway.
Default Gateways are *global* for the entire machine. The fact that the GUI
lets you assign one to each Nic is a "fluke". By all rights the Default
Gateway Settings once applied at one Nic should automatically be "greyed
out" on the remaining Nics to avoid redundant or conflicting gateway
settings,....but they didn't ask me before they designed the GUI the way it
is :-).

Let me try to explain the "sessions" thing. I am not going to claim it is a
perfect and pristine explaination, but it should work......

A session has packets going both ways but it is at a different level than
requesting a web page from a web server. Part 1B and 2A are the key reasons
why it does not always use the same Nic it received the original request on.

1. Your request a web page.
A. URL is resolved
B. A routing decision is maded based on destination address.
C. Syn packets and Ack packets are exchanged and a "session" is
established.
D. You send the GET or POST along with accompanying data.
E. Server receives the "package" and acknowledges.
F. The session *ends*

In the interim,...the Webserver processes the request and prepares the
material that it will send back to you.

2. Server sends data back to you
A. A routing decision is maded based on destination address.
B. Syn packets and Ack packets are exchanged and a *new* "session" is
established.
D. Server sends the data.
E. Your machine receives the "data" and acknowledges.
F. The session *Ends*

"Alan_S" <(E-Mail Removed)> wrote in message
news:32201E91-683D-4A52-A06F-(E-Mail Removed)...
> I am trying to set up a load balanced web farm. Here is the issue:
> I have a server with 2 NIC's one that runs through the load balancer
> (192.168.1.xxx) and one that doesn't (172.16.xxx.xxx). I have been unable
to
> figure out haow to make traffic that comes in on one NIC go back out on
the
> same.

In general you can't do this.

The only practically way to get such load
balancing on a single server with NICs on
the same "subnet" (broadcast domain) is to
use a special NIC driver (and maybe special
NICs) called "Teaming NIC" or "Teaming NIC
driver".

> The only thing I have been able to do is send either all or none of
> the traffic through the load balancer. Each NIC having it's own gateway
> doesn't work. Any help would be greatly appreciated.

No since only ONE "default gateway" is ever
active at any one time. (The others are only used
when the first is 'down'.)