NLB cLuster on 9702E

[strelok]

Hello,

We are trying to setup NLB cluster, and we faced with some issues.
So, I attached network scheme.

We have OmniSwithces 9702E
AOS 6.4.6.340.R01
boards OS9-GNI-C24E

The main problem is that client cannot reach NLB cluster from another network via another router.
Please, look at network scheme for detatils.


If all nodes of nlb cluster is available, client can reach nlb cluster via router 1 without problem.
In case of one of node nlb cluster down (Server1) client cann't reach nlb cluster (new active node Server2) via router 2.
Moreover we can see that client send ARP requests to router 1 and no any arp requests from router 1 towards router 2.

Also we don't see arp requests in vlan 100 from Router 1 to Router 2, when all nodes of NLB cluster is UP.

[strelok]

Here is attached network scheme.

[alexC]

Hi strelok,

It happens because Omniswitch, through which NLB cluster is working, should act only as L2 device. Otherwise it will use ARP table to make a decision, which have an association only with a single port. The key of NLB is that we have cluster MAC address (VMAC) in answers from NLB nodes, which will never learn in Omniswitch MAC address table. Using this trick NLB cluster causes Omniswitch to make broadcast delivery to all nodes. If Omniswitch will work as L3 device and use ARP table, it will send traffic only to a single node.

[strelok]

Hello, alexC.

Thank you very much for explanation !

Are there any workarounds in our case ?

[strelok]

Hello, alexC.

Thank you very much for explanation !

Are there any workarounds in our case ?

[alexC]

Check this topic

viewtopic.php?f=191&t=15911&start=10

I hope this helps.

[narasimha928]

Hello

can you share the cluster configuration on router 1 and router 2 on erp ring.