Multiple External IPs to Multiple Firewalls

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Multiple External IPs to Multiple Firewalls

L0 Member

I am sure this is going to be something simple, but I am admittedly stumped (not hard to do).


I have a block of External IP addresses assigned by our ISP , say


The gateway is . This contains a single physical port . This is connected to a switch to allow distribution of multiple ports. 


I have 2 firewalls attached.  


Firewall one is assigned  

Firewall two is assigned   . 


If I add my new PA 850 with an external interface setting of, it blocks access to  The other firewall on is not affected. 

I have created no static routes or NAT on the 850 at this point.  

If I set the external address of the 850 to it still blocks 15.  

If I swap the IP addresses, that is, set the 850 to and set Firewall2 to, it works.  So then all 3 firewalls are up. 


I could leave it at that. However a) I don't know why its blocking devices further down the IP address list and I would like to and b)  I have some public webservices pointing to the original IP address of so would rather not change that.







Cyber Elite
Cyber Elite


What do the logs on the PAN say as to why the traffic is getting blocked? Might want to put in a policy of something like this for the PAN:

source zone untrust source ip destination zone untrust destination ip any application/any service action is allow


Just a thought.

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