2X of PA820 Active/ Passive Design question

[craigpaolozzi]

Hi All

After some advice, planning to have 2 X PA820 pairs of Active/ Passives, Inner and outer firewalls protecting some internal networks.

See the diagram, Does the HA2 link pass data plane traffic at all?  Or can it?

There could be a scenario that one set of FW's can failover and the primary unit of one trying to speak to the standby unit of the other.  

Or is the only solution to put a switch in between the green cables FW Connect to stop this issue?

Thanks All

[craigpaolozzi]

Heres a better diagram of the full solution......so this is for an OT environment so sensitive networks.

So there are networks behind the Inner Palo Alto pair.....they will be accessed by the Cisco LAN behind the Outer Pair of Palo Altos

[craigpaolozzi]

Heres another of the situation I want to aviod;

if the active FW in the bottom pair wants to send traffic north, it will send via the passive not - which will fail

And if HA2 doesnt send the traffic to the active pair....then still the traffic is dropped

[BPry]

@craigpaolozzil,

if the active FW in the bottom pair wants to send traffic north, it will send via the passive not - which will fail

And if HA2 doesnt send the traffic to the active pair....then still the traffic is dropped

Why  do you thing this will ever be sent via the passive node? The passive node does not accept or forward any traffic, nothing is "alive" so to speak outside of your management interface. It has absolutely no way to send/receive traffic. 

[craigpaolozzi]

Because the active node in the latest diagram I sent only has a link to the passive node, if that was in active mode it would be fine and would pass traffic.

[BPry]

@craigpaolozzi,

That would be a design flaw then. As I stated previously if you aren't going to use some sort of switch/router in the middle and directly connect these two clusters you would need to have each individual node to have it's own link to both the opposite firewalls. If that isn't done you don't have a route to the active unit and this breaks your entire design.