Re: Convergance of one NLB cluster "takes out" other on same network segment.

Hello,

NLB Fundamentals - FAQ
http://technet2.microsoft.com/windowsserver/en/library/b098ca89-c162-4a60-bf47-eab85203d7f41033.mspx?mfr=true

It has heartbeat:
No, the heartbeat packets, which are emitted every second by each host, consume less than 1,500 bytes.

But it doesn't need a back end network:

Q. Do the Heartbeats Need to Go on a Back-End Network?

A. No, the heartbeat packets are always sent out on the same network interface on which data packets are received and sent. There is no need for an additional back-end network for the control (heartbeat) packets. In fact, in order to be able to detect connectivity failures on the load-balanced network adapter, NLB actually requires that heartbeats traverse the load-balanced network adapter.


cross over cable is NOT supported with NLB:
Using crossover cable causes load balancing not to work
http://support.microsoft.com/kb/242248/en-us
--
Cordialement,
Mathieu CHATEAU
http://lordoftheping.blogspot.com


"Rodney R. Fournier" <rod@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message news:EE87728A-D9EC-449C-A838-7CF775E756A6@xxxxxxxxxxxxxxxx
Ok here are the issues as I see them.

1) NLB DOES NOT have a heartbeat, so your 10.x networks are useless
2) You don't list the # of any of the computers, so I am not sure you have NLB configured properly.
3) From your description, I am not sure yet how Cluster A ever affects Cluster B. Are you connected to a layer 2 or 3 switch? VLANed? Multicast? Unicast?

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

"Craig Gjerdingen" <gjer0005@xxxxxxx> wrote in message news:B1E7BBB7-CBD6-41FD-9CF7-781A490BFC56@xxxxxxxxxxxxxxxx
I have an issue with the config listed below. I'll get the terms wrong here so please forgive me. I think Cluster A runs some sort of heart beat health check. The nodes in Cluster A attempt to converge. When they do they can't find each other and then Cluster A is in an unconverged state. This network activity causes knocks out Cluster B casuing it to reconverge. Which it does, be it is unavailble during this time. The end state is that Cluster B is reconverged and available, and Cluster A's nodes can't see each other as part of the Cluster but appear to function. If you connection locally to a node in Cluster A they only see localhost as a node in the cluster. Any help would be nice.

Thanks,

Craig Gjerdingen

Cluster A - (cluster IP on public network 1 160.94.1.#))
Node 1
Cluster - Nic 1 (public network 1 160.94.1.#) priority 1
Private - Nic 2 (private network 1 10.1.1.#) via private switch segment

Node 2
Cluster - Nic 1 (public network 1 160.94.1.#) priority 2
Private - Nic 2 (private network 1 10.1.1.#) via private switch segment

Cluster B - (cluster IP on public network 1 160.94.1.#))
Node 1
Cluster - Nic 1 (public network 1 160.94.1.#) priority 1
Private - Nic 2 (private network 1 10.0.0.#) via cross over cable

Node 2
Cluster - Nic 1 (public network 1 160.94.1.#) priority 2
Private - Nic 2 (private network 1 10.0.0.#) via cross over cable


.

Relevant Pages

  • Re: NLB on 2 servers with IIS 6, Static replication
    ... tell the web author to publish to the Cluster IP address 192.168.203.70. ... communications will occur over the NLB network. ... When posting to the clustered address, you won't know which server actually ...
    (microsoft.public.windows.server.clustering)
  • Re: Network fails when adding new NLB host
    ... NLB with Teamed NICs is a touchy area. ... Using teaming adapters with network load balancing may cause network ... > We are trying to add a new host too an existing 2 server NIb cluster ...
    (microsoft.public.windows.server.clustering)
  • Re: Subnet error message
    ... I do have have a hub in front of my nlb setup and all 4 nic are connect to ... And the uplink is a Cisco switch with VLAN's. ... > prevents the Network Load Balancing heartbeats of one or more hosts ... > from reaching all of the other hosts in the cluster. ...
    (microsoft.public.windows.server.clustering)
  • Re: NLB with 2 NICs question
    ... the heartbeat only travel over the public network meaning the adapter ... We recommend 2 NICS with Unicast mode so that cluster hosts can communicate ... Please refer to KB "Unicast NLB nodes cannot communicate ...
    (microsoft.public.windows.server.clustering)
  • Re: Local traffic and active/standby NLB configs
    ... part of the NLB cluster? ... On the server side, we use PHP scripts ... then you should configure a management network and set ... sharing a NLB cluster address. ...
    (microsoft.public.windows.server.clustering)