topic Using HA without a virtual mac possible? in General Topics

Using HA without a virtual mac possible?

Tim_Reckling — Wed, 08 Nov 2023 10:16:52 GMT

Hello,

as the title says: I want to implement an HA active-passive setup on a virtualization platform that doesn't support MAC address changes on the VM side. Therefore, a newly generated virtual MAC is unfortunately not an option.

So, is there a way to disable virtual MAC for HA?

Thanks
Tim

Re: Using HA without a virtual mac possible?

TomYoung — Wed, 08 Nov 2023 12:06:25 GMT

Hi @Tim_Reckling ,

Could you provide more information? Here is a good link for HA on VM-Series -> https://docs.paloaltonetworks.com/vm-series/9-1/vm-series-deployment/about-the-vm-series-firewall/vm-series-in-high-availability. For example, the original HA document for Azure does not use virtual MACs. However, the Azure deployment guide https://www.paloaltonetworks.com/resources/reference-architectures/azure recommends using the Azure Load Balancer with 2 independent NGFWs for faster failover, in which case the virtual MAC is not required.

PANW has reference architectures for AWS, GCP, etc. https://www.paloaltonetworks.com.au/resources/reference-architectures

So, there may be some good documents for your virtualization platform to help solve your issue.

With regard to normal HA configuration, you must use the virtual MAC address.

Thanks,

Tom

Re: Using HA without a virtual mac possible?

Raido_Rattameister — Wed, 08 Nov 2023 13:43:25 GMT

In VMware environment you need to use firewall own IPs not virtual to avoid setting virtual switch into promiscuous mode.

This setting can be adjusted at

Device > Setup > Management > Use Hypervisor Assigned MAC Addresses

Be aware that in this case firewall failover will cause gratuitous arp to be sent out and not every device accepts it.

For example Palos themselves don't update arp table if gratuitous arp is received.

So assuming you have physical Palo at the perimeter and virtual Palos in HA inside.

Virtual Palo failover will cause outage because perimeter Palo don't care about gratuitous arp.