Put Cisco MAC on PAN firewall? / Change interface MAC address

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L0 Member

Put Cisco MAC on PAN firewall? / Change interface MAC address

We're migrating from Cisco ASA to PAN firewalls.

The ASA is default gateway for many subnets & hosts.

 

To achieve a smooth migration, one thought is to put the ASA's MAC address on the PAN firewall, so that the hosts don't need to ARP for the new MAC.

 

Can this be done?

I don't see an option to change the MAC under Network / Interfaces.

 

There's an article that says this cannot be done, but the KB is two years old, and I was wondering if that's changed since then.

https://live.paloaltonetworks.com/t5/Management-Articles/Can-the-Interface-MAC-Address-be-Modified/t...

 

TIA


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L7 Applicator

You can send Gratuitous ARP from Palo after you switch over so that devices would update their ARP table.

 

https://live.paloaltonetworks.com/t5/Management-Articles/Trigger-a-Gratuitous-ARP-GARP-from-a-Palo-A...

Enterprise Architect @ Cloud Carib www.cloudcarib.com
ACE, PCNSE, PCNSI

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L7 Applicator

You can send Gratuitous ARP from Palo after you switch over so that devices would update their ARP table.

 

https://live.paloaltonetworks.com/t5/Management-Articles/Trigger-a-Gratuitous-ARP-GARP-from-a-Palo-A...

Enterprise Architect @ Cloud Carib www.cloudcarib.com
ACE, PCNSE, PCNSI

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Cyber Elite

Even if you could mimic the ASA's MAC address (you can't on PAN) you wouldn't really want to as that would set precidance to keep doing it. Just set it up and have it send out a Gratuitous ARP and get your ARP entries updated. The process won't take long.  

Highlighted
L6 Presenter

Just to add to all comments. We had a similar situation and GARP worked and fixed the problem.

 

dxx@Axxx-FW1> test arp gratuitous ip 1xx.4x.7x.0/24 interface ethernet1/1

2 ARPs were sent


dxx@Axxx-FW1>

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