problem LOAD SHARING Multicast

[Sharky]

Dear Sirs:

I request assistance with the following item:

I am installing a cluster in LOAD SHARING Unicast and it works OK, and I tried to make the switch to LOAD SHARING Multicast, but at the moment to implement it crashes, I may not send or receive mail.

The configuration at the different devices:

1. Parameters used in SW.

A. Disabling IGMP Snooping

To disable IGMP snooping run:

No IP IGMP snooping



B. Disabling Multicast Limits

To disable multicast limits run:

no storm-control multicast level (On all the interface the SW)

1. Parameter used on the Router

a. Configuring a Static ARP Entry on the Router

arp _._._._ (ip cluster) 01:00:5E:__:__:__ (mac multicast) arpa

Between the cluster check point and the mail server there is a pix, but in this PIX y not set no parameter.

Please, I request your help for find if there is some other parameter, that I need to set up on the Switch, router and/or PIX, thanks for your help.

[chillyjim]

Just use Unicast mode, it will save you a lot of problems. Multicast mode is very switch dependent and many will not work with it no matter what you do.

[Routerkid1]

I agree new mode ha or unicast load share aka pivot mode will work well.

[BarryStiefel]

Originally Posted by Sharky

Dear Sirs:

I request assistance with the following item:

I am installing a cluster in LOAD SHARING Unicast and it works OK, and I tried to make the switch to LOAD SHARING Multicast, but at the moment to implement it crashes, I may not send or receive mail.

The configuration at the different devices:

1. Parameters used in SW.

A. Disabling IGMP Snooping

To disable IGMP snooping run:

No IP IGMP snooping



B. Disabling Multicast Limits

To disable multicast limits run:

no storm-control multicast level (On all the interface the SW)

1. Parameter used on the Router

a. Configuring a Static ARP Entry on the Router

arp _._._._ (ip cluster) 01:00:5E:__:__:__ (mac multicast) arpa

Between the cluster check point and the mail server there is a pix, but in this PIX y not set no parameter.

Please, I request your help for find if there is some other parameter, that I need to set up on the Switch, router and/or PIX, thanks for your help.

What I keep hearing is that the more expensive your switch is, the less likely it's able to support Multicast mode. Buy a cheap switch or use Unicast mode.

[Sharky]

Thanks for help. But now I need your help for What is the difference between unicast and multicast conections and pros and cons between both.
Very grateful for your collaboration

[sebastan_bach]

hi sharky in multicast load sharing mode. in clusterXL deployments the internal devices will have their default gateway pointing to the cluster virtual ip address and similarly on the external interface.

so lets say ur internal users are trying to get to the internet. in this case when the internal router or host does a arp request for the mac address of the virtual ip address any of the active cluster members will respond with a multicast mac to the host. so when the host sends the traffic to the multicast address all the cluster members will receive the frame at layer 2. then each cluster will make a decision whether to process or drop the packet. making sure that no firewalls are processing the same packet and atleast one firewall is processing the packet.

in load sharing unicast mode. in this mode only a single cluster member also called pivot mac address is associated with the cluster virtual ip address.

so here when the host request the mac address of the virtual ip address the pivot responds with his interface mac address. once the pivot receives the frame then only the pivot makes the decision function as to whether forward the packet by himself or forward it to other cluster members. the other members when they receive the packet by the pivot they simply just forward it they don;t make any decision.

the difference in the mode is only how the cluster members receive the packet for load sharing. rest the working on clusterXL remains the same.

hope this help u out.

regards

sebastan

[Sharky]

Thanks for your collaboration

regards