Re: Windows 2003 Network Load Balancing Problem

Shane:

I wonder if it would be of value to post the question over on the IIS web
site, as well. Maybe they can shed some light
on the behavior. Perhaps its the use of the host headers to perform the
routing to virtual web servers that is causing it,
in particular if you are getting any ancient http 1.0 traffic (which doesn't
support host headers, if memory serves me right -
got to dig out my "better than a sleeping pill" O'Reilly HTTP book).

Ken

"ShaneO" <shane.ogrady@xxxxxxxxx> wrote in message
news:1149806674.858403.219190@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
I hadn't been checking up on this thread actually. Must go through the
blog you posted above. (it's midnight so I'll do it tomorrow)

Sadly my servers websites were configured with specific IPs and host
headers, and not "All Unassigned".

I had intended to set up the servers in the future with all sites load
balanced across two servers, as opposed to just one specific site, but
I will await Rodney's answer to you Ken, first.

I find it very strange why the NLB driver can receive on a virtual IP
but then send on a different IP. If for example I set up (like Ken has
done) servers configured as below, what would the sending (response
from the webserver) IP be:

Server A Server B
-------------
-------------
NIC 1: No "real address" on either, set up through NLB manager to
have 10.10.10.199

NIC 2: 192.168.0.10 192.168.0.11

(I haven't tested this config)

Shane


Ken L wrote:
Rodney:

Just had a epiphany as to what may be the cause of Shane's problem. What
if
he set his IIS website to use ALL UNASSIGNED addresses rather than
specifically pointing it at the single virtual cluster address. I can
see
very easily where one of the other addresses associated with the NIC
would
be used for the response from the web server rather than the virtual
address. The response address is probably the first address associated
with
the NIC - - which would be dependent on order the addresses were added
to
network connection. This would account for the different addresses used
between the two NLB servers. Shane, are you still following this
thread?
Is this how your servers are (were) configured?

I'll take a look at the blog you suggested when I get a chance. Thought
I'd
post the thought above before it flitted out of my poor little brain.

Ken (firm believer in the IT law of unintended consequences - If it can
behave inconsitently for no apparent reason, it will!).


"Rodney R. Fournier [MVP]" <rod@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message news:%23veR%23DviGHA.4572@xxxxxxxxxxxxxxxxxxxxxxx
Are you setup like this -
http://msmvps.com/blogs/clustering/archive/2005/10/21/71893.aspx ?

Cheers,

Rodney R. Fournier

MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering Website
http://www.msmvps.com/clustering - Blog
http://www.clusterhelp.com - Cluster Training
ClusterHelp.com is a Microsoft Certified Gold Partner


"Ken L" <kenl@xxxxxxxxxxxxx> wrote in message
news:ufEFlzniGHA.1508@xxxxxxxxxxxxxxxxxxxxxxx
Rodney:

I'm still confused. What would be the "real/physical" IP associated
with
the NIC's in my example below? The example I cited below is set up
like
the NLB config I am testing. The only IP addresses I see in the
Network
Connections for the NLB NIC (i.e., NLB NIC in unicast mode on a front
rail switch - ONLY virtual IPs) are the multiple NLB virtual cluster
addresses I've set up. The NLB Manager shows 0.0.0.0 (mask 0.0.0.0)
for
the dedicated IP address. My only non-NLB IP (dedicated management
IP)
is on a separate, back rail NIC. There are only virtual IP addresses
associated with the NLB NIC, as far as I can tell. Are you talking
about
the MAC addresses?

Ken


"Rodney R. Fournier [MVP]" <rod@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in
message news:OWaqDUjiGHA.4080@xxxxxxxxxxxxxxxxxxxxxxx
Traffic always comes into the Virtual but always leaves on the
real/physical.

Cheers,

Rodney R. Fournier

MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering Website
http://www.msmvps.com/clustering - Blog
http://www.clusterhelp.com - Cluster Training
ClusterHelp.com is a Microsoft Certified Gold Partner


"Ken L" <kenl@xxxxxxxxxxxxx> wrote in message
news:%23%23OYUSbiGHA.1276@xxxxxxxxxxxxxxxxxxxxxxx
Rodney:

I am confused regarding your answer below. What would happen in the
case where the NIC servicing the cluster ONLY has virtual addresses
on
it. For example

Server A Server B
100.x.x.1 virt clstr addr 100.0.0.1
100.x.x.2 virt clstr addr 100.0.0.2

(and further assume that there is a second, back rail NIC with
dedicated addresses on it for admin purposes).

What would be the "real" IP address in this case, based on your
response to Shane?

Won't the web server respond to the browser through the address the
transaction came in on (i.e., the virtual address). I can see where
the MAC addresses will be mangled, but I don't see why the NLB
intermediate driver would change the IP address of the web server.

Ken

"Rodney R. Fournier [MVP]" <rod@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote
in
message news:ekgFrU9ZGHA.4144@xxxxxxxxxxxxxxxxxxxxxxx
The NLB address is not real, it's a Virtual. NLB sends on the real
network address. That is just how NLB works, sounds like you need
to
accept the real server's IPs in your app.

Cheers,

Rodney R. Fournier

MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering Website
http://msmvps.com/clustering - Blog
http://www.clusterhelp.com - Cluster Training
ClusterHelp.com is a Microsoft Certified Gold Partner


<shane.ogrady@xxxxxxxxx> wrote in message
news:1145619637.106060.30500@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi,
I'm hoping someone can answer my question about Windows Network
Load
Balancing.
Running Windows 2003 Enterprise SP1.

I run many different websites and thus have many different public
IPs.
Usually I have assigned the public IPs to my network interface in
Windows and associated the websites via IPs in IIS and/or using
host
headers.
I want to set up NLB across two servers for one of my main sites
which
can get quite busy.

I set up the site using the NLB manager in Windows 2003 with one
public
IP address for the cluster.
So the setup was thus:

Server A - Public Interface Server B - Public Interface
-------------------------------------
-------------------------------------
100.x.x.1 100.x.x.2
100.x.x.3 (Clustered IP) 100.x.x.3 (Clustered IP)
100.x.x.20 100.x.x.30
100.x.x.15
100.x.x.18

It all seemed to work well with perfmon showing the load was being
shared evenly accross both servers for the specific website. I set
up
rules for port 80 and 443 with affinity set to single host
(Classic
ASP
E-Commerce Application) for both rules.

However a lot of e-commerce transactions failed due to my payment
processor not recognising the IP that the request had come from.

What was happening was that although the NLB cluster was receiving
request correctly on the clustered IP it seemed to send requests
out
on
a different IP, in this instance 100.x.x.1 or 100.x.x.30

Is this normal for NLB? I can't imagine so? Is there any way to
fix
this?














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