Zone based firewall configuration concept in Palo Alto is similar to any other firewall. In this lesson, we will learn to configure Palo Alto Zone Based Firewall. We will be using PAN OS 8.1.0, and our firewall management is already configured. If you are new in Paloalto firewall, then you are recommended to check Palo Alto Networks Firewall Management Configuration.

LAB Goals:

  • 3 zones for External, Internal and DMZ network and bind with appropriate interfaces
  • Internal zone (LAN users) can reach Internet
  • DMZ WEB server access from Internal Zone
  • External people will be able to access WEB server only through NAT

LAB Diagram:

Palo Alto Zone Based Firewall Configuration LAB

After completing this LAB, we will develop some knowledge to configure Zone, Virtual Routers, Interface Configuration, Policies, NAT and Routing (Static).

In policy section, we will allow every application and services (any) to make article short and easier for new comers. Later we will discuss in detail. So, let’s get started with Palo Alto Zone Based Firewall Configuration.

Configuration:

Zone creating and binding to appropriate interfaces

Creating Zone:

To create the zone, we need to go to Network >> Zones and then click Add.

Zone Section

Now, name the Zone and select zone type. Below image shows External zone, creating with L3 type. Similarly, we also created other two zones named Internal and DMZ with L3 zone type.

Creating Zone

Creating Virtual Routers:

To create virtual routers, we have to go Network >> Virtual Routers and then click Add.

Virtual Routers Section

You will find lots of options here, including all the routing configuration. Just name the Virtual Router, rest will be configured later. In our example, we are creating Virtual Routers name OUR_VR.

Creating Virtual Routers

Interface Configuration:

For interface configuration, first of all we need to go Network >> Interfaces and then click on the interfaces.

In our example, Ethernet 1/1 is our outside interface. So, after clicking Ethernet 1/1, we are giving comment (description), Interface type as Layer3. Then, we will assign the virtual router OUR_VR and zone External.

Interface Config 1

On the same page, we have to add IP address. We are using IPv4, so we are clicking on IPv4 and adding the IP address for external interface by clicking Add.

Interface Config 2

Similarly, we need to do the same steps for Internal and DMZ zone to add IP addresses for them. In our LAB 10.1.1.1/24 is Internal interface IP and 192.168.1.1/24 is DMZ interface IP.

Finally, commit all the configuration by clicking Commit from right top corner.

Reaching Internet from Internal Zone

First of all, we need to add routing configuration. To do so, we need to go to Network >> Virtual Routers and then click newly created virtual router named OUR_VR.

Adding Static Route

Below are the configuration of our LAB setup.

Adding Static Route 2

Now, we need to configure the policy for Inside to Outside communication. By default, interzone communication is blocked.

In policy, we need to configure minimum 4 section. We are configuring according below listed information.

Policy for Inside to Outside 2

General:
Name: INTERNAL_TO_EXTERNAL
Rule Type: interzone

Source:
Source Zone: Internal
Source Address: 10.1.1.0/24

Destination:
Destination Zone: External
Source Address: any

Action:
Action: Allow

Now, we need to create NAT rule. To create go to Policies >> NAT and click Add to add the NAT rule.

We use below information to create the NAT rule.

General
Name: INTERNAL_TO_INTERNET

Original Packet
Source Zone: Internal
Destination Zone: External
Destination Interface: ethernet 1/1
Source Address: 10.1.1.0
Destination Address: Any

Translated Packet
(Source Address Translation)
Translation Type: Dynamic IP And Port
Address Type: Interface Address
Interface: ethernet 1/1
IP Address: 172.16.100.201/24

NAT Rule

Now, we need to commit all the configuration by clicking Commit.

Verification:

Let’s have a http request to www.paloaltonetworks.com from Internal network.

C:\>ipconfig

Windows IP Configuration

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::6cf7:1072:c575:5
   IPv4 Address. . . . . . . . . . . : 10.1.1.10
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.1.1.1

INSIDE CHECK

Sure enough, our Internal LAN users BOB can access the internet.

WEB Server configuration on DMZ

DMZ server is connected to ethernet 1/3 interface which belong to DMZ zone. Our WEB server IP is 192.168.1.10. Now, let’s create policies for communication between INTERNAL and DMZ zone.

INTERNAL to DMZ:

General:
Name: INTERNAL_TO_DMZ
Rule Type: interzone

Source:
Source Zone: Internal
Source Address: 10.1.1.0/24

Destination:
Destination Zone: External
Source Address: 192.168.1.0/24

Action:
Action: Allow

DMZ to INTERNAL

General:
Name: DMZ_TO_INTERNAL
Rule Type: interzone

Source:
Destination Zone: External
Source Address: 192.168.1.0/24

Destination:
Source Zone: Internal
Source Address: 10.1.1.0/24

Action:
Action: Allow

We can verify the result by hitting WEB server IP http://192.168.1.10 from Internal LAN PC (10.1.1.10).

WEB SERVER Hit

Now, time for External users. We will configure Destination NAT for outside users. To create destination NAT, we have to go Policies >> NAT and then click Add to add the NAT rule.

Below are our NAT configuration.

General
Name: DESTINATION_NAT

Original Packet
Source Zone: External
Destination Zone: External (it's because we will hit external IP)
Destination Interface: ethernet 1/1
Source Address: any
Destination Address: 172.16.100.199 (this is our Outside IP :P )

Translated Packet
(Destination Address Translation)
Translation Type: Static IP
Translated Address: 192.168.1.10

Destination NAT

Verification:

To verify, let’s do a http request to http://172.16.100.199 which is our WEB server external IP.

DNAT External IP Test

Result looks perfect. Finally, we can reach WEB server from External Zone.

Written by Rajib Kumer Das

I am Rajib Kumer Das, a network engineer with 7+ years of experience in multi-vendor environment. In my current company, I am responsible to take care critical projects and it's support cases. I do have several vendor certificates and have plans to go further.

This article has 2 comments

  1. Junix Reply

    Hello Rajib,

    Very helpful post for a PAN neophyte like me.

    Thanks for sharing.

    Kind regards,

    Junix

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