Multicast MAC

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Feb 21st, 2008
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Hey folks,

We have 2 new Sidewinder firewalls that we plan on using in an active/active HA cluster.

From what I've read, the virtual IP (VIP)adapter uses a multicast MAC address, so I must make a static arp entry which will

"connect" my multicast L2 (MAC) address with your virtual IP address.

I've done this with this command:

arp xxx.yyy.235.10 0100.5e49.eb0a ARPA

After I did this, I was still unable to ping the VIP (xxx.yyy.235.10).

I can ping the IP's of the firewall interfaces just fine...just not the VIP.

Any other hints/tips anyone can provide?

thanks, SM

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smahbub Fri, 02/29/2008 - 07:19
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The workaround is to identify the end station that is generating frames with a multicast source MAC address. Typically, such frames are transmitted from a traffic generator (for example, SmartBits) or third party devices that share a multicast MAC address, such as a load balancing firewall or server product.

Use a sniffer to identify the device generating the frames with multicast MAC addresses as source MAC addresses. This must be done at the time the messages are being logged. Start the trace at the port indicated in the error message.

blong Fri, 05/02/2008 - 04:02
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Steve, we also have sidewinder FW's and I ran into the same thing. Along with the arp entry, you also have to add a static mac entry to add the multicast mac to the sidewinder ports. otherwise, the switch does not know where to send the packets so it will send it to all ports.

rc5295509 Thu, 12/20/2012 - 06:54
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We have the same problem..  but I try to configure the mac, and not is posible... this is the message...

6509(config)#mac address-table static 0100.5e0d.0225 vlan 13 inter giga 1/24

IP-based forwarding is enabled, can't accept group DMAC configuration

I try with : ARP XX.XX.2.37 0100.5e0d.0225 ARPA interface Gi1/24  !!!   Is the same result...

Some ideas for this solution...


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