Windows 2003 NLB, not accessible from other subnet.

Hi All,
I’ve setup 2 web servers (each with 2 NICs) into one Windows NLB cluster.
I’m able to access this cluster very well from same subnet front-end IP are,
but not from other subnet.
Details-
ServerA-
Front-end-
IP 192.168.40.217
Subnet mask: 255.255.255.0
Gateway: 192.168.40.1

Backend
IP 192.168.13.49
Subnetmask 255.255.255.0
Gateway: Null

ServerB-
Front-end-
IP 192.168.40.218
Subnet mask: 255.255.255.0
Gateway: 192.168.40.1

Backend
IP 192.168.13.50
Subnet mask 255.255.255.0
Gateway: Null

NLB IP – 192.168.40.219
Subnet mask 255.255.255.0

I need to load balance only Front-end NIC and back-end is only for SQL access.

I’m able to access this NLB IP within 192.168.40.x subnet without any
issues, and also able to see the NLB Manager showing all servers “Converged�.
All settings default.
Cluster Operation Mode – Multicast
Defined Port rules: 0-65535
Both,
Multiple Host
Affinity : Single


Please help me in this, not sure what am I missing.

Hello,

Does the router between the 2 subnet accept multicast arp ?

I guess it is rejecting the virtual mac. Is it a layer3 switch ?

Are you in multicast or unicast ?

If the backend doesn't have a gateway as you typed (null), how can this
work ?



Cordialement,
Mathieu CHATEAU
french blog: http://www.lotp.fr
english blog: http://lordoftheping.blogspot.com


Ashutosh a écrit :
> Hi All,
> I’ve setup 2 web servers (each with 2 NICs) into one Windows NLB cluster.
> I’m able to access this cluster very well from same subnet front-end IP are,
> but not from other subnet.
> Details-
> ServerA-
> Front-end-
> IP 192.168.40.217
> Subnet mask: 255.255.255.0
> Gateway: 192.168.40.1
>
> Backend
> IP 192.168.13.49
> Subnetmask 255.255.255.0
> Gateway: Null
>
> ServerB-
> Front-end-
> IP 192.168.40.218
> Subnet mask: 255.255.255.0
> Gateway: 192.168.40.1
>
> Backend
> IP 192.168.13.50
> Subnet mask 255.255.255.0
> Gateway: Null
>
> NLB IP – 192.168.40.219
> Subnet mask 255.255.255.0
>
> I need to load balance only Front-end NIC and back-end is only for SQL access.
>
> I’m able to access this NLB IP within 192.168.40.x subnet without any
> issues, and also able to see the NLB Manager showing all servers “Converged�.
> All settings default.
> Cluster Operation Mode – Multicast
> Defined Port rules: 0-65535
> Both,
> Multiple Host
> Affinity : Single
>
>
> Please help me in this, not sure what am I missing.
>

"Ashutosh" <> wrote in message
news:7346EE5F-CADA-42D5-B947-...
> Hi All,
> I’ve setup 2 web servers (each with 2 NICs) into one Windows NLB cluster.
> I’m able to access this cluster very well from same subnet front-end IP
> are,
> but not from other subnet.
> Details-
> ServerA-
> Front-end-
> IP 192.168.40.217
> Subnet mask: 255.255.255.0
> Gateway: 192.168.40.1
>
> Backend
> IP 192.168.13.49
> Subnetmask 255.255.255.0
> Gateway: Null
>
> ServerB-
> Front-end-
> IP 192.168.40.218
> Subnet mask: 255.255.255.0
> Gateway: 192.168.40.1
>
> Backend
> IP 192.168.13.50
> Subnet mask 255.255.255.0
> Gateway: Null
>
> NLB IP – 192.168.40.219
> Subnet mask 255.255.255.0
>
> I need to load balance only Front-end NIC and back-end is only for SQL
> access.
>
> I’m able to access this NLB IP within 192.168.40.x subnet without any
> issues, and also able to see the NLB Manager showing all servers
> “Converged�.
> All settings default.
> Cluster Operation Mode – Multicast
> Defined Port rules: 0-65535
> Both,
> Multiple Host
> Affinity : Single

The issue is probably that you are using Multicast. Many routers/switches
are not able to multicast non-multicast addresses.

You will need to switch to Unicast if you want to be able to access the NLB
from other network segments.

--
Russ Kaufmann,
MVP, MCSE: Messaging and Security, MCT, MCITP, MCTS and other stuff

ClusterHelp.com, a Microsoft Certified Gold Partner
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