Two Palos (not paired) on the same LAN have duplicate MAC addresses

TomElkins — Tue, 14 Jul 2020 17:14:17 GMT

I have two datacenters each with independent Palo Alto setups

Each site is configured Active/Passive, there is no peering of the Palo's at one site, with the Palos at the other site.
My Cisco L3 configured switches are reporting a duplicate MAC address ( on the ports connected to the Palo) and on a connection to my nexus switches.
The nexus switches at each datacenter have a dedicated fiber between them; at 1st I thought there was a loop.
Then I did a show interface all on the palo's at each site, and they are using some of the same MAC addresses.

The only thing thats not duplicated are unused interfaces and the HA interfaces.

See below results of Show Interface All.
I same a technical doc that states you can't change the MAC, there has to be a way to correct this.

Site 1				Site 2			all

name	id	speed/duplex/state	mac address	name	id	speed/duplex/state	mac address
----------------	-----------	-----------------------------	------------------------	----------------	---	-------------------------------------	------------------------
				ethernet1/1	16	1000/full/up	00:1b:17:00:0b:10
				ethernet1/2	17	ukn/ukn/down(autoneg)	00:1b:17:00:0b:11

ethernet1/4	19	1000/full/up	00:1b:17:00:0b:13
ethernet1/5	20	1000/full/up	00:1b:17:00:0b:14	ethernet1/5	20	1000/full/up	00:1b:17:00:0b:14
ethernet1/6	21	ukn/ukn/down(autoneg)	00:1b:17:00:0b:15
ethernet1/7	22	1000/full/up	00:1b:17:00:0b:16

ethernet1/9	24	10000/full/up	00:1b:17:00:0b:18	ethernet1/9	24	10000/full/up	00:1b:17:00:0b:18
				ethernet1/10	25	10000/full/up	00:1b:17:00:0b:19
ethernet1/11	26	ukn/ukn/down(autoneg)	00:1b:17:00:0b:1a
ethernet1/12	27	10000/full/up	00:1b:17:00:0b:1b	ethernet1/12	27	10000/full/up	00:1b:17:00:0b:1b
ae1	48	[n/a]/[n/a]/up	00:1b:17:00:0b:30	ae1	48	[n/a]/[n/a]/up	00:1b:17:00:0b:30
ae2	49	[n/a]/[n/a]/up	00:1b:17:00:0b:31	ae2	49	[n/a]/[n/a]/up	00:1b:17:00:0b:31
ae3	50	[n/a]/[n/a]/up	00:1b:17:00:0b:32	ae3	50	[n/a]/[n/a]/up	00:1b:17:00:0b:32
ae4	51	[n/a]/[n/a]/up	00:1b:17:00:0b:33
ae5	52	ukn/ukn/down(unknown)	00:1b:17:00:0b:34	ae5	52	[n/a]/[n/a]/up	00:1b:17:00:0b:34
ae6	53	[n/a]/[n/a]/up	00:1b:17:00:0b:35	ae6	53	[n/a]/[n/a]/up	00:1b:17:00:0b:35
dedicated-ha1	5	1000/full/up	e8:98:6d:8f:ab:05	dedicated-ha1	5	1000/full/up	84:d4:12:19:48:05
dedicated-ha2	6	1000/full/up	e8:98:6d:8f:ab:06	dedicated-ha2	6	1000/full/up	84:d4:12:19:48:06
vlan	1	[n/a]/[n/a]/up	00:1b:17:00:0b:01	vlan	1	[n/a]/[n/a]/up	00:1b:17:00:0b:01
loopback	3	[n/a]/[n/a]/up	00:1b:17:00:0b:03	loopback	3	[n/a]/[n/a]/up	00:1b:17:00:0b:03
tunnel	4	[n/a]/[n/a]/up	00:1b:17:00:0b:04	tunnel	4	[n/a]/[n/a]/up	00:1b:17:00:0b:04

Re: Two Palos (not paired) on the same LAN have duplicate MAC addresses

Vikram511 — Wed, 15 Jul 2020 09:39:29 GMT

@TomElkins

The Virtual mac in HA setup is calculated using group-id from HA configuration. Can you check what group-id is used in HA configuration of both pairs. Its recommended to use different group-id for HA pairs on the same LAN to avoid such issues.

Re: Two Palos (not paired) on the same LAN have duplicate MAC addresses

TomElkins — Wed, 15 Jul 2020 12:36:30 GMT

Thanks that's exactly what it was. A colleague copied my firewall config onto the other one to speed up the build, and didn't change the HA ID.

topic Re: Two Palos (not paired) on the same LAN have duplicate MAC addresses in General Topics

Two Palos (not paired) on the same LAN have duplicate MAC addresses

Re: Two Palos (not paired) on the same LAN have duplicate MAC addresses

Re: Two Palos (not paired) on the same LAN have duplicate MAC addresses