NLB Multicast on A7506

[dcampregher]

Hi,

I've configured NLB multicast on HP A7506 but not works fine. After to connect the links of the servers on the HP switch and then configure the the syntax:

mac-address multicast 03bf-0afc-02fa interface Bridge-Aggregation10 vlan 10

The IP os the cluster is stop to reponse.

The others comands are tested:

undo arp check enable

arp static mac ip

But not works. In the Cisco switch, if i entry of the commands:

arp 10.253.3.253 03bf.0afc.02fa ARPA

The cluster response again, anyway the links are in the HP Switch, but the arp multicast

and the router of the vlan is the cisco...  :-|

Thks

[dcampregher]

HI, nothing ?

[manuel.bitzi]

Hi

MS NLB is only supported on SD or EA-Blades. Not on SC or SA. Its a hardware issue.

You can make a workaround like that, works great:

http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?lang=en&cc=us&taskId=120&prodSeriesId=4177876&prodTypeId=12883&objectID=c02656362

br

Manuel

[dcampregher]

Thanks for the reply. 

7506 are SD. I've  03 cluster  NLB in my network, if apply the solution in workarround, i've high cost per port in the 02 chassis.

Other solution for this case ? I think wich the problem is very cases in the world, all the clients apply this work arround ?

What HP says for this ?

Thks..

Diogo

[dcampregher · Accepted solution]

HI,

The problem is: The supervisor is a SA, where only EB and SD card supports Multicast ARP.

[manuel.bitzi]

Fabrics (Cisco call them supervisor) don't have a ASIC-Typ. Only when the Fabric have Ports, these ports are SD ... but not the Fabric itself.

[dcampregher]

Hello Manuel,

Is there a way for the Multicast ARP NLB  in the 7506 ? Or the solution is use other switch (e.g 5120) for this role ?

Do you talk about "Fabrics don't have a ASIC-Typ" ?

Regards

[manuel.bitzi]

Let me draw your design (simplified):

7506 (Router) ------ ciscoswitch ---- NLB1

                                              |

                                          NLB2

correct?

Then it works with all types of ASIC-Blades on the 7500. Only set "undo arp check enable". No static arp nor static mac-multicast needed. Works without.

ASIC-Types: 7500 has different ASIC-Types on the Blades (SA, SC, SD, EA, ED) with different memory (Routing-, MAC-Table-Size, etc) and differenz featuressets (MPLS, VRF, Tunneling, etc). But this has nothing to do with the Fabric (MPU), it is "neutral".

br

Manuel

[dcampregher]

Draw of the network:

7506 ( Router )---- NLB01/NLB02 Don't work ( undo arp check enable applied )

 NLB01/NLB02-------7506 --------5120 ( Router ) Works fine ( Only the undo arp check enable applied )

I don't understand what reason the first solution don't work. The HP L3 and R&D purpose the second solution.

[Tomas_Kubica]

Reason is I believe the following:

L2 switch and multicast NLB - no problem, you may just want to limit where traffic goes by having smaller VLAN, statically apply multicast MAC on ports or use IGM

L3 device and mulicast NLB - you need to have unicast IP associated with mulicast MAC. Comware can do this as explain in this thread, other vendor may not support dynamic mode, but will let you set ARP enry manually.

Problem comes with combination of both - so you connect NLB to L3 switch. When switch is installing unicast routing rule into TCAM it needs to specify to ports (your nodes) - and that is problem with some ASICs - like on SD card, but not on SC card.

Note that scenario which works for you is that your routing device needs to asociate only one physical port (downlink) with cluster IP.

Tomas