Correct IP setting when two firewalls connected to one ISP.

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Correct IP setting when two firewalls connected to one ISP.

L4 Transporter

We have two PA's connecting to one ISP. One is just being set up.

 

The ISP is "10.10.10.0/27"

Route is "10.10.10.5"

 

Is it correct to have both firewall external vlan interfaces as such

 

FW1 "10.10.10.99/27"

FW2 "10.10.10.122/27"

 Vlan 140

 

Vlan.jpg

 

 

 

And for the NAT

 

NAT.jpg

 

 

FW1 Main Nat "10.10.10.99/27"

FW2 Main Nat "10.10.10.122/27"

 

 

 

 

I ask, because the new firewall is logging packets for the old firewall. I am seeing "x.x.x.99" on the firewall with VIP "x.x.x.122"

 

monitor.jpg

 

 

 

11 REPLIES 11

It's easy to get confused by Palo Alto's various uses of VLAN.

 

A "VLAN" interface is different from a "Layer 3" interface that has 802.1q vlan tags enabled.

 

On a PA device "VLAN" interfaces are used to create a virtual switch using ports on the firewall, and allow them to operate as layer 2 interfaces without routing abilities.  Essentially, it create a bridged interface using all the VLAN interfaces.

 

If you want to enabled tagged (or untagged) 802.1q vlans on interfaces, then configure them as "Layer 3" and create sub-interfaces with the vlan tag set there.

 

Would be nice if PA updated their UI to remove the ambiguous and confusing "VLAN" interface type.  "Bridge" would be more accurate.

I couldn't agree with you more.  This really confused me the first time I used PAN and the documentation explaining this wasn't great.

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