Cisco IT Blog Awards 2021 – Finalist..!

It’s a great pleasure to announce that we are selected as one of the finalists in the IT Blog Awards 2021, hosted by Cisco. Can’t explain how it feels to be in the list among leading IT blogs, for the Third Time (2018,2020 and 2021 now).

We would like to Congratulate all the finalists and wish them the best in the competition.

There are 58 entries in the Blogs category and 17 entries in the Vlogs and Podcasts category. There are only these categories this time, unlike previous times (where awards were given in different categories of contents).

You can vote now for the best blogs and vlogs/podcasts, based on the value they are creating, the quality of contents etc… This is your opportunity to vote for the contents which always help you at work or in your studies. Read more

You can select upto 5 Blogs and 5 Vlogs/Podcasts and rank them 1-5. We would be happy if you are having our site as well in your 5.

VOTE NOW

You can find more details/rules in the above voting link. Have a detailed look at the blogs/vlogs/podcasts, and vote NOW..!

Palo Alto Interview Questions and Answers – Part II

Plao Alto Interview Questions and Answers

This post is a continuation to one of our recent post where we discussed a few questions and answers on Palo Alto firewall. Here we are adding another set of Q&A based on our readers interest. Hope this will help you in improving your knowledge of the PA firewall.

1. How to publish internal website to internet. Or how to perform destination NAT ?

To publish internal website to outside world, we would require destination NAT and policy configuration. NAT require converting internal private IP address in to external public IP address. Firewall policy need to enable access to internal server on http service from outside .We can see how to perform NAT and policy configuration with respect to following scenario Read more

Provide the access to 192.168.10.100 through the public IP address 64.10.11.10 from internet

Following NAT and policy rules need to be created.

NAT:-> Here we need to use pre-NAT configuration to identify zone. Both source and destination Zone should be Untrust-L3 as source and destination address part of un trust zone

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Policy-> Here we need to use Post-NAT configuration to identify zone. The source zone will be Untrust-L3 as the source address still same 12.67.5.2 and the destination zone would be Trust-L3 as the translated IP address belongs to trust-l3 zone.

We have to use pre-NAT IP address for the source and destination IP address part on policy configuration. According to packet flow, actual translation is not yet happen, only egress zone and route look up happened for the packet. Actual translation will happen after policy lookup . Please click here to understand detailed packet flow in PA firewall.  Just remember the following technique so it will be easy to understand

In firewall rule,

Zone: Post NAT

IP address: Pre NAT

In NAT rule,

Zone: Pre NAT

Final Configuration looks like below:

2. What is Global Protect ?

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GlobalProtect provides a transparent agent that extends enterprise security Policy to all users regardless of their location. The agent also can act as Remote Access VPN client.  Following are the component

Gateway : This can be or more interface on Palo Alto firewall which provide access and security enforcement for traffic from Global Protect Agent

Portal: Centralized control which manages gatrway, certificate , user authentication and end host check list

Agent : software on the laptop that is configured to connect to the GlobalProtect deployment.

3. Explain about virtual system ?

A virtual system specifies a collection of physical and logical firewall interfaces and security zones.Virtual system allows to segmentation of security policy functionalities like ACL, NAT and QOS. Networking functions including static and dynamic routing are not controlled by virtual systems. If routing segmentation is desired for each virtual system, we should have an additional virtual router.

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4.Explain about various links used to establish HA or HA introduction ?

PA firewall use HA links to synchronize data and maintain state information. Some models of the firewall have dedicated HA ports—Control link (HA1) and Data link (HA2), while others require you to use the in-band ports as HA links.

Control Link :  The HA1 links used to exchange hellos, heartbeats, and HA state information, and management plane sync for routing, User-ID information and synchronize configuration . The HA1 should be layar 3 interface which require an IP address

Data Link : The HA2 link is used to synchronize sessions, forwarding tables, IPSec security associations and ARP tables between firewalls in an HA pair. The HA 2 is a layer 2 link

Backup Links: Provide redundancy for the HA1 and the HA2 links. In-band ports are used as backup links for both HA1 and HA2. The HA backup links IP address must be on different subnet from primary HA links.

Packet-Forwarding Link: In addition to the HA1 and HA2 links, an active/active deployment also requires a dedicated HA3 link. The firewalls use this link for forwarding packets to the peer during session setup and asymmetric traffic flow.

4. What protocol used to exchange heart beat between HA ?

ICMP

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5. Various port numbers used in HA ?

HA1: tcp/28769,tcp/28260 for clear text communication ,tcp/28 for encrypted communication

HA2: Use protocol number 99 or UDP-29281

6. What are the scenarios for fail-over triggering ?

->if one or more monitored interfaces fail

->if one or more specified destinations cannot be pinged by the active firewall

->if the active device does not respond to heartbeat polls (Loss of three consecutive heartbeats over period of 1000 milliseconds)

7. How to troubleshoot HA using CLI ?

>show high-availability state : Show the HA state of the firewall

>show high-availability state-synchronization : to check sync status

>show high-availability path-monitoring : to show the status of path monitoring

>request high-availablity state suspend : to suspend active box and make the current passive box as active

8. which command to check the firewall policy matching for particular destination ?

>test security-policy-match from trust to untrust destination <IP>

9.Command to check the NAT rule ?

>test nat-policy-match

10. Command to check the system details ?

>show system info  // It will show management IP , System version and serial number

11. How to perform debug in PA ?

Following are the steps

Clear all packet capture settings

>debug dataplane packet-diag clear all

set traffic matching condition

> debug dataplane packet-diag set filter match source 192.168.9.40 destination 4.2.2.2
> debug dataplane packet-diag set filter on

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Enable packet capture

> debug dataplane packet-diag set capture stage receive file rx.pcap
> debug dataplane packet-diag set capture stage transmit file tx.pcap
> debug dataplane packet-diag set capture stage drop file dp.pcap
> debug dataplane packet-diag set capture stage firewall file fw.pcap
> debug dataplane packet-diag set capture on

View the captured file

view-pcap filter-pcap rx.pcap

12. What you mean by Device Group and Device Template.?

Device group allows you to group firewalls which is require similar  set of policy , such as firewalls that manage a group of branch offices or individual departments in a company. Panorama treats each group as a single unit when applying policies. A firewall can belong to only one device group. The Objects and Policies are only part of Device Group.

Device Template :

Device Templates enable you to deploy a common base configuration like Network and device specific settings to multiple firewalls that require similar settings.
This is available in Device and Network tabs on Panorama

13. Why you are using Security Profile .?

Security Profile using to scans allowed applications for threats, such as viruses, malware, spyware, and DDOS attacks.Security profiles are not used in the match criteria of a traffic flow. The security profile is applied to scan traffic after the application or category is allowed by the security policy. You can add security profiles that are commonly applied together to a Security Profile Group

Following are the Security Profiles available

  • Antivirus Profiles
  • Anti-Spyware Profiles
  • Vulnerability Protection Profiles
  • URL Filtering Profiles
  • Data Filtering Profiles
  • File Blocking Profiles
  • WildFire Analysis Profiles
  • DoS Protection Profiles

Enjoyed Reading.? If you found the above contents useful and easily understandable, you can download a bundle of most frequently asked interview question and answers via the below link. We are sure it will help you increase your confidence in Palo Alto and will help you in tackling the interviews with positive results.Please click below link (you will be re-directed to the payment gateway  – Instamojo) to Download PDF for less than 6 USD (INR 400). This contains 45 + Most frequently asked PA interview question on the following topics with detailed explanation.

  • Question from VPN setup and troubleshooting
  • Migration of ASA into PA
  • Questions from AppID and Vulnerability Protection
  • PA Best practices
  • Other Hot questions and explanation

Hope this helped in improving your Palo Alto knowledge or clearing some of your doubts. Please let us know if you have any queries/comments.

Palo Alto Interview Questions and Answers – Part I

Plao Alto Interview Questions and Answers

Some of our readers had requested for a post with some of the common questions and answers for the Palo Alto Firewall, after reading our post on PA Firewall. Following are some of the questions normally asked for PA interview. Please use the comment section if you have any questions to add

1. Why Palo Alto is being called as next generation firewall ?

Ans: Next-generation firewalls include enterprise firewall capabilities, an intrusion prevention system (IPS) and application control features. Palo Alto Networks delivers all the next generation firewall features using the single platformparallel processing and single management systems, unlike other vendors who use different modules or multiple management systems to offer NGFW features. Palo Alto NGFW different from other venders in terms of Platform, Process and architecture Read more

2. Difference between Palo Alto NGFW and Checkpoint UTM  ?

PA follows Single pass parallel processing while UTM follows Multi pass architecture process

3. Describe about Palo Alto architecture and advantage ?

Architecture- Single Pass Parallel Processing (SP3) architecture

Advantage: This Single Pass traffic processing enables very high throughput and low latency – with all security functions active.  It also offers single, fully integrated policy which helps simple and easier management of firewall policy

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4. Explain about Single Pass and Parallel processing architecture ?

Single Pass : The single pass software performs operations once per packet. As a packet is processed, networking functions, policy lookup, application identification and decoding, and signature matching for any and all threats and content are all performed just once.  Instead of using separate engines and signature sets (requiring multi-pass scanning) and instead of using file proxies (requiring file download prior to scanning), the single pass software in next-generation firewalls scans content once and in a stream-based fashion to avoid latency introduction.

Parallel Processing :   PA designed with separate data and control planes to support parallel processing. The second important element of the Parallel Processing hardware is the use of discrete, specialized processing groups to perform several critical functions.

  • Networking: routing, flow lookup, stats counting, NAT, and similar functions are performed on network-specific hardware
  • User-ID, App-ID, and policy all occur on a multi-core security engine with hardware acceleration for encryption, decryption, and decompression.
  • Content-ID content analysis uses dedicated, specialized content scanning engine
  • On the controlplane, a dedicated management processor (with dedicated disk and RAM) drives the configuration management, logging, and reporting without touching data processing hardware.

5. Difference between PA-200,PA-500 and higher models ?

In PA-200 and PA-500, Signature process and network processing implemented on software while higher models have dedicate hardware processer

6. What are the four deployment mode and explain ?
  1. Tap Mode : Tap mode allows you to passively monitor traffic flow across network by way of tap or switch SPAN/mirror port
  2. Virtual wire : In a virtual wire deployment, the firewall is installed transparently on a network segment by binding two interfaces together

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  1. Layer 2 mode : multiple interfaces can be configured into a “virtual-switch” or VLAN in L2 mode.
  2. Layer 3 Deployment : In a Layer 3 deployment, the firewall routes traffic between multiple interfaces. An IP address must be assigned to each interface and a virtual router must be defined to route the traffic.

7. What you mean by Zone Protection profile ?

Zone Protection Profiles offer protection against most common flood, reconnaissance, and other packet-based attacks. For each security zone, you can define a zone protection profile that specifies how the security gateway responds to attacks from that zone. The following types of protection are supported:

-Flood Protection—Protects against SYN, ICMP, UDP, and other IP-based flooding attacks.

-Reconnaissance detection—Allows you to detect and block commonly used port scans and IP address sweeps that attackers run to find potential attack targets.

-Packet-based attack protection—Protects against large ICMP packets and ICMP fragment attacks.

Configured under Network tab -> Network Profiles -> Zone protection.

8. What is u-turn NAT and how to configure ?

U-turn NAT is applicable when internal resources on trust zone need to access DMZ resources using public IP addresses of Untrust zone.

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Let’s explain based on below scenario.

In above example, the website company.com (192.168.10.20) statically NAT’ed with public IP address 81.23.7.22 on untrusted zone. Users in the corporate office on the 192.168.1.0/24 segment need to access the company webpage. Their DNS lookup will resolve to the public IP in the Internet zone. The basic destination NAT rules that provide internet users access to the web server will not work for internal users browsing to the public IP .

Following are the NAT rule and policy definition.

  Next Page

Enjoyed Reading.? If you found the above contents useful and easily understandable, you can download a bundle of most frequently asked interview question and answers via the below link. We are sure it will help you increase your confidence in Palo Alto and will help you in tackling the interviews with positive results.Please click below link (you will be re-directed to the payment gateway  – Instamojo) to Download PDF for less than 6 USD (INR 400). This contains 45 + Most frequently asked PA interview question on the following topics with detailed explanation.

  • Question from VPN setup and troubleshooting
  • Migration of ASA into PA
  • Questions from AppID and Vulnerability Protection
  • PA Best practices
  • Other Hot questions and explanation

Click Here for Part 2 of this post, another set of questions for you.