Windows Network Load Balancing and routing question

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Guest

Hello:

We have an odd one.
First the set up:
2 separate machines.
Each with 2 network cards each. One built in, one on the PCI bus.
We set these machines up to allow us to access them internally, for
management purposes on a 10.x.127.x network. For the sake of this
conversation the ip's are .1 anb .1 on the above network. The mask is a /24.
We use a single gatewayto the rest of our internal network. We access them
via terminal services ADMIN. This works very well. This is a isolated
internal network.

On the other side we have these machines set for Windows Network Load
Balancing.
The network would be 10.x.126.x and the separate IP's are .1 and .2, the NLB
address is .3. This address is then NAT'ed through our firewall to the
outside world. Again this works well. The page is published and those who
need access to the content can get it. We use a /24 mask and a assign a
gateway. When doing this we get an error message refering to multiple
gateways providing redundancy to a single network, and that multiple gateways
to separate networks can cause performance issues. This is an isolated DMZ
netowrk. With no direct routing to the private network.

The Problem:
We are seeing perfomance issues. From time to time users experience latency
on the pages, latency that is not atributable load or network traffic. Also
the page generates CFMHTTP requests that fail.These requests are to the
outside world. Also any web page requests fail, as do pings and HTTP
requests. The page functions and responds to HTTP requests from any other
hosts.

If we remove the private side gateway, it works properly, however we cannot
manage it as is at a remote site. Well we could, it would just be awkward. If
we remove the public gateway then no pages are served to the outside world,
however pings and HTTP and CFMHTTP requests are handled.

The question boils down to this:
How does Windows handle Multi-Homing?

Windows 2003 server, Web Edition, no servicepack( We have had issues with SP1)

Thanx
GM
 
gmasson said:
The question boils down to this:
How does Windows handle Multi-Homing?

Default Gateways are "global" for the entire machine, don't let the fact
that it is entered in at a specific Nic fool you. Only use one Default
Gateway. Use Static Routes in the routing table for other "paths".

By definition there can only be one active Default Gateway (0.0.0.0 in the
routing table).

159168 - Multiple Default Gateways Can Cause Connectivity Problems
http://support.microsoft.com/kb/159168/EN-US/

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
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