Re: NLB Cluster - Ping fails or long time to reply from outside local subnet

Yes, NIC1 and NIC2 (in each machine) are dual port Broadcom cards. They are
definitely not being teamed and I have tested the locally administered
address is being set correctly on the cluster adapter. ARP reports
everything as expected.

I will set-up the cluster using the DLink card, NIC3 which was added
afterwards.

Regardless, none of this would suggest why it works locally but not from
outside the LAN. It is as if the router is intermittently not accepting the
packets to/from the LAA address or something.


"Chuck [MSFT]" <ctimon@xxxxxxxxxxxxxxxxxxxx> wrote in message
news:ewVUlnC7HHA.1900@xxxxxxxxxxxxxxxxxxxxxxx
Let's simplify this.....disable all but one NIC in each member of the NLB
cluster, setup NLB on it, plug the NICs into a hub, remember those? :{>
then uplink the hub to a switch port and test.

If you have NLB in your environment....keep a spare dumb hub
around....never know when you might need it.

--
Chuck Timon, Jr.
Microsoft Corporation
Windows Server 2008 Readiness Team
This posting is provided 'AS IS" with no warranties, and confers no
rights.

"Bookham Measures" <bookham_measures_no_spam@xxxxxxxxx> wrote in message
news:OlGc7c96HHA.5404@xxxxxxxxxxxxxxxxxxxxxxx
Hello

We have set-up NLB cluster with two servers, ultimately for an IIS
application.

Everything functions perfectly when the clients are on the same subnet as
defined by their IP address.

Hosts outside the subnet, i.e. come via a router, cannot get reliable
ping responses. They get a mixture of "request timed out" or a delayed
reply, between 54ms to 1510ms. The ping summary always reports more than
60% packet loss. This applies to the cluster IP address and the
dedicated IP on the cluster NIC in each server. The mixture of timeouts
and replies come at different times when running simultaneous pings to
the three IP addresses.

All configuration has been performed via the Network Load Balancing
Manager.

As we have plenty of adapters the cluster has been configured in Unicast
mode. We have set-up a VLAN on our switch and plugged the dedicated
cluster NICs in to those ports. The configuration is as follows.


Server 1
---------
NIC1: x.x.16.121 DG x.x.16.1 in VLAN
NIC2: x.x.16.123 DG x.x.16.1
NIC3: 192.168.1.21 DG not set.

Server 2
---------
NIC1: x.x.16.122 DG x.x.16.1 in VLAN
NIC2: x.x.16.124 DG x.x.16.1
NIC3: 192.168.1.22 DG not set.

Cluster
-------
Server 1 NIC1 Priority 1
Server 2 NIC1 Priority 2
Cluster IP x.x.16.125
Equal

NIC3 on each server is numbered so as to communicate with the database
cluster. I have tried removing the default gateway from NIC1/2 to see if
I can different results, but I cannot. Interestingly, when one of the
servers is offline the problem persists. Remember, this problem only
occurs from outside the x.x.16.0 subnet. Hosts on the same subnet (not
in the VLAN), have no problems communicating to the cluster or NIC1 IP
addresses.

When the cluster is deleted via the Manager, the IPs on NIC1 in each
machine start responding to pings normally with good times.

NIC2 in both servers responds to pings from anywhere satisfactorily, the
whole time, (they are not in the VLAN used by NIC1s).

NIC1 and NIC2 in each machine are a "Broadcom NetXtreme Gigabit Ethernet"
dual port adapter and have the latest driver from the IBM website. Both
servers are IBM System-X 3850 M2s running Windows 2003 Server R2 SP2. (32
Bit). Quad Xeon 2.5Ghz with 3 Gb RAM.

The switch is a Foundry EdgeIron 48G.

Where can I go next to troubleshoot this problem? The fact that the IPs
respond normally from everywhere when there is no cluster configured,
must mean that there is something wrong at the NLB driver level.

Many thanks in advance.

David






.

Relevant Pages

  • Re: NLB Cluster - Ping fails or long time to reply from outside local subnet - SOLVED
    ... Windows Server 2008 Readiness Team ... now allows me to ping the cluster and dedicated IP from a remote location. ... Of course, now if I remove the cluster configuration, I will not be able to connect as the permanent MAC address will be assigned back to the dedicated adapter's IP address in the ARP tables. ... I have disabled one of the Broadcom NICs, (NIC1 which had an IP from the same subnet). ...
    (microsoft.public.windows.server.clustering)
  • Re: NLB Cluster - Ping fails or long time to reply from outside local subnet
    ... Windows Server 2008 Readiness Team ... I have disabled one of the Broadcom NICs, (NIC1 which had an IP from the same subnet). ... I should re-iterate that pings respond perfectly when performed from another host on the same subnet/x.x.16.0 network. ... They are definitely not being teamed and I have tested the locally administered address is being set correctly on the cluster adapter. ...
    (microsoft.public.windows.server.clustering)
  • Re: NLB Cluster - Ping fails or long time to reply from outside local subnet
    ... " I have tried removing the default gateway from NIC1/2 to ... MVP - Windows Server - Clustering ... We have set-up NLB cluster with two servers, ... NIC1: ...
    (microsoft.public.windows.server.clustering)
  • Re: NLB Cluster - Ping fails or long time to reply from outside local subnet
    ... With NLB, it is pretty common practice to break the problem down into its simplest components and see if it works, if it works then build up from there. ... Windows Server 2008 Readiness Team ... I will set-up the cluster using the DLink card, ... NIC1: ...
    (microsoft.public.windows.server.clustering)
  • Re: NLB Cluster - Ping fails or long time to reply from outside local subnet - SOLVED
    ... Windows Server 2008 Readiness Team ... cluster on a separate DLink card in multicast mode. ... I thought that the litmus test was that the router functions fine ... member of the NLB cluster, setup NLB on it, plug the NICs ...
    (microsoft.public.windows.server.clustering)