NLB

Discussion:

NLB

(too old to reply)

Walid

2007-08-17 01:01:34 UTC

I have an NLB setup in unicast mode with two network cards load balancing an
IIS website. I believe I have NLB configured properly as my site seems load
balanced. I know this by bringing down one server and testing my site. The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
error for the other host:

Host unreachable, error connecting to "host.domain.com"

Any help would be appreciated

Rodney R. Fournier [MVP]

2007-08-17 02:23:07 UTC

Permalink

Are you trying NLB Manager from one of the NLB machines? NLB machines have a
hard time with that. Try using a third admin machine to run the manager
from!

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

Post by Walid
I have an NLB setup in unicast mode with two network cards load balancing an
IIS website. I believe I have NLB configured properly as my site seems load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Walid

2007-08-17 14:42:35 UTC

Permalink

Thank-you very much for responding!
Yes, from my workstation the NLB Manager works and I can see both nodes
showing converged. What is bizarre is that sometimes the NLB manager works
from each node without any issues. Mostly, though, it will see "host
unreachable" error for one of the nodes.

I want to make sure that my TCP/IP settings are correct. Would you please
tell me if this is the correct configuration:

NLB is configured for UNICAST and I have 2 NICS on each node. All
interfaces are on the same subnet.

Node1/NIC1
DIP: 192.168.1.10/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)

Node1/NIC2
IP: 192.168.1.11/24
No default gateway configured
No DNS configured
No WINS configured

Node2/NIC1
DIP: 192.168.1.20/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)

Node1/NIC2
IP: 192.168.1.21/24
No default gateway configured
No DNS configured
No WINS configured

I would really appreciate if you could explain the following as well:
1. What traffic goes through the DIP?
2. How or is NIC2 being used and if so, for what type of traffic?
3. When I RDP to any node, which interface is being used?
4. Is UNICAST mode a proper method for this configuration?
5. Does it matter which interface should have DNS,WINS, DEFAULT GATEWAY in
this case?

Thanks in advance!

Walid

Post by Rodney R. Fournier [MVP]
Are you trying NLB Manager from one of the NLB machines? NLB machines have a
hard time with that. Try using a third admin machine to run the manager
from!
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

Chuck [MSFT]

2007-08-17 15:13:21 UTC

Permalink

So, you intentioanlly put all NICs in the nodes on the same network?
--
Chuck Timon, Jr.
Microsoft Corporation
Windows Server 2008 Readiness Team
This posting is provided 'AS IS" with no warranties, and confers no rights.

Post by Walid
Thank-you very much for responding!
Yes, from my workstation the NLB Manager works and I can see both nodes
showing converged. What is bizarre is that sometimes the NLB manager works
from each node without any issues. Mostly, though, it will see "host
unreachable" error for one of the nodes.
I want to make sure that my TCP/IP settings are correct. Would you please
NLB is configured for UNICAST and I have 2 NICS on each node. All
interfaces are on the same subnet.
Node1/NIC1
DIP: 192.168.1.10/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)
Node1/NIC2
IP: 192.168.1.11/24
No default gateway configured
No DNS configured
No WINS configured
Node2/NIC1
DIP: 192.168.1.20/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)
Node1/NIC2
IP: 192.168.1.21/24
No default gateway configured
No DNS configured
No WINS configured
1. What traffic goes through the DIP?
2. How or is NIC2 being used and if so, for what type of traffic?
3. When I RDP to any node, which interface is being used?
4. Is UNICAST mode a proper method for this configuration?
5. Does it matter which interface should have DNS,WINS, DEFAULT GATEWAY in
this case?
Thanks in advance!
Walid

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site seems load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Rodney R. Fournier [MVP]

2007-08-17 15:24:41 UTC

Permalink

That has to be a problem, I know I have not tested a config that like. Why
would you need 3 IPs on 2 NICs within the same network?

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

Post by Chuck [MSFT]
So, you intentioanlly put all NICs in the nodes on the same network?
--
Chuck Timon, Jr.
Microsoft Corporation
Windows Server 2008 Readiness Team
This posting is provided 'AS IS" with no warranties, and confers no rights.

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site
seems
load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Walid

2007-08-17 15:38:00 UTC

Permalink

On NIC1: One for virtual IP and one for dedicated Ip. Both are required for
Network Load Balancing, correct? I figured we would need this for the
virtual IP and the cluster traffic.

The second NIC and the 3rd IP address, I learned, would be used for other
network traffic other than cluster traffic. Would you please shed some light
into this??

Many thanks!!

Walid

Post by Rodney R. Fournier [MVP]
That has to be a problem, I know I have not tested a config that like. Why
would you need 3 IPs on 2 NICs within the same network?
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

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site
seems
load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Walid

2007-08-17 16:06:00 UTC

Permalink

Thanks. So, how would you configure the NLB given my configuration. It is
an internal website that needs to be load balanced?

While it is a best practice to have 2 NICs. The two NICs would be on
different subnets and the NLB NIC would be Unicast. You are not doing that.
You second NIC in your current config is simple not needed and confusing me
and probably your traffic/NLB.
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

Post by Walid
On NIC1: One for virtual IP and one for dedicated Ip. Both are required for
Network Load Balancing, correct? I figured we would need this for the
virtual IP and the cluster traffic.
The second NIC and the 3rd IP address, I learned, would be used for other
network traffic other than cluster traffic. Would you please shed some light
into this??
Many thanks!!
Walid

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site
seems
load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Rodney R. Fournier [MVP]

2007-08-17 16:22:44 UTC

Permalink

One NIC on the network configured with Multicast to a hub plugged into your
switch. Disable the second NIC!

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

Post by Walid
Thanks. So, how would you configure the NLB given my configuration. It is
an internal website that needs to be load balanced?

Post by Walid
On NIC1: One for virtual IP and one for dedicated Ip. Both are
required
for
Network Load Balancing, correct? I figured we would need this for the
virtual IP and the cluster traffic.
The second NIC and the 3rd IP address, I learned, would be used for other
network traffic other than cluster traffic. Would you please shed some light
into this??
Many thanks!!
Walid

Post by Walid
Thank-you very much for responding!
Yes, from my workstation the NLB Manager works and I can see both nodes
showing converged. What is bizarre is that sometimes the NLB
manager
works
from each node without any issues. Mostly, though, it will see "host
unreachable" error for one of the nodes.
I want to make sure that my TCP/IP settings are correct. Would you please
NLB is configured for UNICAST and I have 2 NICS on each node. All
interfaces are on the same subnet.
Node1/NIC1
DIP: 192.168.1.10/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)
Node1/NIC2
IP: 192.168.1.11/24
No default gateway configured
No DNS configured
No WINS configured
Node2/NIC1
DIP: 192.168.1.20/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)
Node1/NIC2
IP: 192.168.1.21/24
No default gateway configured
No DNS configured
No WINS configured
1. What traffic goes through the DIP?
2. How or is NIC2 being used and if so, for what type of traffic?
3. When I RDP to any node, which interface is being used?
4. Is UNICAST mode a proper method for this configuration?
5. Does it matter which interface should have DNS,WINS, DEFAULT
GATEWAY
in
this case?
Thanks in advance!
Walid

Post by Rodney R. Fournier [MVP]
Are you trying NLB Manager from one of the NLB machines? NLB
machines
have a
hard time with that. Try using a third admin machine to run the manager
from!
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

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site
seems
load
balanced. I know this by bringing down one server and testing
my
site.
The
problem I have is with NLB Manager. When I launch the NLB
Manager
and
connect to the cluster, I can connect to one host but I get the
following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Rodney R. Fournier [MVP]

2007-08-17 15:45:22 UTC

Permalink

While it is a best practice to have 2 NICs. The two NICs would be on
different subnets and the NLB NIC would be Unicast. You are not doing that.
You second NIC in your current config is simple not needed and confusing me
and probably your traffic/NLB.

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

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site
seems
load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Walid

2007-08-17 15:32:04 UTC

Permalink

Yes. This is an internal web application that is being load balanced. Is
this an issue?

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site seems load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Rodney R. Fournier [MVP]

2007-08-17 15:37:15 UTC

Permalink

My guess (since I have not tested it), YES!!!

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

Post by Walid
Yes. This is an internal web application that is being load balanced. Is
this an issue?

Post by Walid
I have an NLB setup in unicast mode with two network cards load
balancing
an
IIS website. I believe I have NLB configured properly as my site
seems
load
balanced. I know this by bringing down one server and testing my site.
The
problem I have is with NLB Manager. When I launch the NLB Manager and
connect to the cluster, I can connect to one host but I get the following
Host unreachable, error connecting to "host.domain.com"
Any help would be appreciated

Russ Kaufmann [MVP]

2007-08-17 17:52:07 UTC

Permalink

and you are enabling NLB on this NIC, right?

Post by Walid
Node1/NIC2
IP: 192.168.1.11/24
No default gateway configured
No DNS configured
No WINS configured

This NIC should be on a separate network segment that can be routed so you
can use it to connect to the node and manage the node, for example, apply
patches and manage content.

Post by Walid
Node2/NIC1
DIP: 192.168.1.20/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)

and you are enabling NLB on this NIC, right?

Post by Walid
Node1/NIC2
IP: 192.168.1.21/24
No default gateway configured
No DNS configured
No WINS configured

This NIC should be on a separate network segment that can be routed so you
can use it to connect to the node and manage the node, for example, apply
patches and manage content.

Post by Walid
1. What traffic goes through the DIP?

In Unicast - none. See
http://msmvps.com/blogs/clusterhelp/archive/2005/08/07/61965.aspx for more
info.

Post by Walid
2. How or is NIC2 being used and if so, for what type of traffic?

NIC2 is supposed to be used for management. That means, you use this NIC to
connect to a specific node when you need to do work on it.

Post by Walid
3. When I RDP to any node, which interface is being used?

If you RDP to NIC2, then NIC2 is being used. If you RDP to the VIP, then one
of the nodes is being used according to the NLB algorith.

Post by Walid
4. Is UNICAST mode a proper method for this configuration?

Unicast with two NICs is the best practice for NLB.

Post by Walid
5. Does it matter which interface should have DNS,WINS, DEFAULT GATEWAY in
this case?

All interfaces should have DNS, WINS, but only the VIP should have a default
gateway. Your management NIC might need to have a route added for it, but it
should not need a default gateway.
--
Russ Kaufmann
MVP - Windows Server - Clustering
ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp

The next ClusterHelp classes are:
Sep 3 - 6 in Copenhagen
Oct 8 - 11 in New York

Walid

2007-08-17 21:54:13 UTC

Permalink

Thank-you. Would you please look at my responses below. I want to make sure
I will achieve a correct configuration.

Regards,
Walid

Post by Russ Kaufmann [MVP]

and you are enabling NLB on this NIC, right?

That is correct.

Post by Russ Kaufmann [MVP]

Post by Walid
Node1/NIC2
IP: 192.168.1.11/24
No default gateway configured
No DNS configured
No WINS configured

This NIC should be on a separate network segment that can be routed so you
can use it to connect to the node and manage the node, for example, apply
patches and manage content.

Does it have to be on a separate network? Couldn't I use this NIC on the
same network for management purposes?

Post by Russ Kaufmann [MVP]

Post by Walid
Node2/NIC1
DIP: 192.168.1.20/24
VIP: 192.168.1.50/24
Default Gateway: 192.168.1.1
DNS: (dns IP addresses)
WINS: (WINS IP addresses)

and you are enabling NLB on this NIC, right?

That is correct.

Post by Russ Kaufmann [MVP]

Post by Walid
Node1/NIC2
IP: 192.168.1.21/24
No default gateway configured
No DNS configured
No WINS configured

This NIC should be on a separate network segment that can be routed so you
can use it to connect to the node and manage the node, for example, apply
patches and manage content.

Does it have to be on a separate network? Couldn't I use this NIC on the
same network for management purposes?

Post by Russ Kaufmann [MVP]

Post by Walid
1. What traffic goes through the DIP?

In Unicast - none. See
http://msmvps.com/blogs/clusterhelp/archive/2005/08/07/61965.aspx for more
info.

Post by Walid
2. How or is NIC2 being used and if so, for what type of traffic?

NIC2 is supposed to be used for management. That means, you use this NIC to
connect to a specific node when you need to do work on it.

My server name is currently registered with the DIP in the DNS. Do I need
to re-register the name to resolve to the second NIC IP?

Post by Russ Kaufmann [MVP]

Post by Walid
3. When I RDP to any node, which interface is being used?

If you RDP to NIC2, then NIC2 is being used. If you RDP to the VIP, then one
of the nodes is being used according to the NLB algorith.

My server name is currently registered with the DIP in the DNS. Do I need
to re-register the name to resolve to the second NIC IP?

Post by Russ Kaufmann [MVP]

Post by Walid
4. Is UNICAST mode a proper method for this configuration?

Unicast with two NICs is the best practice for NLB.

Can I achieve UNICAST with two NICs within the same network??

Post by Russ Kaufmann [MVP]

Post by Walid
5. Does it matter which interface should have DNS,WINS, DEFAULT GATEWAY in
this case?

Russ Kaufmann [MVP]

2007-08-20 19:04:53 UTC

Permalink

Post by Walid

Post by Russ Kaufmann [MVP]

Post by Walid
Node1/NIC2
IP: 192.168.1.11/24
No default gateway configured
No DNS configured
No WINS configured

This NIC should be on a separate network segment that can be routed so you
can use it to connect to the node and manage the node, for example, apply
patches and manage content.

Does it have to be on a separate network? Couldn't I use this NIC on the
same network for management purposes?

It is not a good practice, but it should work. You do need to provide
routing information for this NIC, though.

Post by Walid

Post by Russ Kaufmann [MVP]

Post by Walid
Node1/NIC2
IP: 192.168.1.21/24
No default gateway configured
No DNS configured
No WINS configured

This NIC should be on a separate network segment that can be routed so you
can use it to connect to the node and manage the node, for example, apply
patches and manage content.

Does it have to be on a separate network? Couldn't I use this NIC on the
same network for management purposes?

It is not a good practice, but it should work. You do need to provide
routing information for this NIC, though.

Post by Walid

Post by Russ Kaufmann [MVP]

Post by Walid
1. What traffic goes through the DIP?

In Unicast - none. See
http://msmvps.com/blogs/clusterhelp/archive/2005/08/07/61965.aspx for more
info.

Post by Walid
2. How or is NIC2 being used and if so, for what type of traffic?

NIC2 is supposed to be used for management. That means, you use this NIC to
connect to a specific node when you need to do work on it.

My server name is currently registered with the DIP in the DNS. Do I need
to re-register the name to resolve to the second NIC IP?

It can have its own name or not even use a name. After all, you can connect
using IP.
--
Russ Kaufmann
MVP - Windows Server - Clustering
ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp

The next ClusterHelp classes are:
Sep 3 - 6 in Copenhagen
Oct 8 - 11 in New York

n***@gmail.com

2017-01-04 00:43:48 UTC

Permalink