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Palo Alto Firewalls Security Zones – Tap Zone, Virtual Wire, Layer 2 and Layer 3 Zones

Posted in Palo Alto Firewalls

Palo Alto Firewalls Security Zones – Tap Zone, Virtual Wire, Layer 2 and Layer 3 Zones - 4.3 out of 5 based on 6 votes

Palo Alto Networks Next-Generation Firewalls rely on the concept of security zones in order to apply security policies. This means that access lists (firewall rules) are applied to zones and not interfaces – this is similar to Cisco’s Zone-Based Firewall supported by IOS routers.

Palo Alto Networks Next-Generation Firewalls zones have no dependency on their physical location and they may reside in any location within the enterprise network. This is also illustrated in the network security diagram below:

Palo Alto Firewall Security Zones can contain networks in different locations Figure 1. Palo Alto Firewall Security Zones can contain networks in different locations

The above topology illustrated shows VLANs 10, 11 ,12 and 2 managed by a Cisco Catalyst 4507R+E Switch and are all part of OSPF Area 0 and visible as routes in the Palo Alto Firewall. A Layer 3 aggregated link has been created between the Palo Alto Firewall (Interface ae1 on each firewall) and the Cisco 4507R+E Switch (Port-Channel 1 & 2).

When aggregation interface ae1.2 on the Palo Alto Firewall is configured to be part of the DMZ Security Zone, all networks learnt by the OSPF routing protocol on interface ae1.2 will be part of the DMZ Security Zone.

Creating a Security Zone involves tasks such as naming the zone, assigning the interfaces to the new zone created and more. Palo Alto Networks Next-Generation Firewalls won’t process traffic from any interface unless they are part of a Security Zone.

The diagram below depicts the order in which packets are processed by the Palo Alto Firewall:

Initial Packet Processing – Flow Logic of Palo Alto Next-Generation Firewall Figure 2. Initial Packet Processing – Flow Logic of Palo Alto Next-Generation Firewall

It is without doubt Zone based firewalls provide greater flexibility in security design and are also considered easier to administer and maintain especially in large scale network deployments.

Palo Alto Networks Next-Generation Firewalls have four main types of Zones namely as shown in the screenshot below:

  • Tap Zone. Used in conjunction with SPAN/RSPAN to monitor traffic.
  • Virtual Wire. Also known as Transparent Firewall.
  • Layer 2. Used when switching between two or more networks.
  • Layer 3. Used when routing between two or more networks. Interfaces must be assigned an IP address.

Spanning Tree BPDUGuard and Errdisable Interface Automatic Recovery

Posted in Cisco Switches - Catalyst Switch Configuration

Spanning Tree BPDUGuard and Errdisable Interface Automatic Recovery - 4.5 out of 5 based on 8 votes

Running Spanning Tree Protocol (STP) in a large network environment can be a challenging task especially when features/enhancements such as BPDU Filter and BPDU Guard need to be configured to help STP adapt to the network infrastructure requirements.

The key to a successful STP deployment is understanding how each STP feature should be used and implemented.

Understanding and Configuring BPDU Guard

BPDU Guard is an STP enhancement which, when enabled, will place a port in the errdisable mode when it receives any BPDU packet from that port.

BPDU Guard is usually configured on access layer ports where we are not expecting to see any BPDU packets arriving from devices connected to these ports e.g computers, printers, IP phones or other user-end devices.

Ports used as uplinks or downlinks to other switches should not have BPDU Guard enabled as these are more likely to have BPDU packets transmitted and received as switches actively monitor for network loops.

BPDU Guard can be configured either in Global mode or Interface mode.

When configured in Global mode the feature is enabled globally for all switch ports configured with port-fast configuration. Port-Fast is an STP feature configured at each individual port that forces the port to go directly into a forwarding state rather than through the normal STP states (Listening, Learning, Forwarding).

While port-fast is a very handy feature that forces a network port to transition immediately to the forwarding state (similar to an unmanaged switch), it must be used with caution as STP won’t be able to immediately detect a network loop through a Port-Fast enabled port.

To configure BPDU Guard in Global mode use the spanning-tree portfast bpduguard default command in Global Configuration Mode:

SW2(config)# spanning-tree portfast bpduguard default

To configure BPDU Guard in Interface mode use the spanning-tree bpduguard enable command under the interface:

SW2(config-if)# spanning-tree bpduguard enable

Note: It is important to keep in mind that if the interface is configured as an access port, with port-fast enabled, and receives a BPDU packet it will automatically be disabled and placed in an errdisabled state.

To help illustrate how BPDU Guard works, we’ve configured port G1/0/1 on our 3750-X as an access link with port-fast and BPDU Guard enabled:

Spanning Tree BPDU Guard configuration and example

Figure 1. Spanning Tree BPDU Guard configuration and example

interface GigabitEthernet1/0/1
 switchport mode access
 switchport access vlan 2
 spanning-tree portfast
 spanning-tree bpduguard enable

Next, we connect another switch (rogue switch) running spanning tree protocol to port G1/0/1 on SW2. As soon as a BPDU packet is received on G1/0/1, here’s how SW2 reacted:

Cisco Press Review for “Cisco Firepower and Advanced Malware Protection Live Lessons” Video Series

Posted in Cisco Technologies

Cisco Press Review for “Cisco Firepower and Advanced Malware Protection Live Lessons” Video Series - 4.3 out of 5 based on 8 votes

Title:              Cisco Firepower and Advanced Malware Protection Live Lessons
Authors:        Omar Santos
ISBN-10:          0-13-446874-0
Publisher:     Cisco Press
Published:     June 22, 2016
Edition:         1st Edition
Language:     English

cisco-firepower-and-advanced-malware-protection-live-lessons-1The “Cisco Firepower and Advanced Malware Protection Live Lessons” video series by Omar Santos is the icing on the cake for someone who wants to start their journey of Cisco Next-Generation Network Security. This video series contains eight lessons on the following topics:

Lesson 1: Fundamentals of Cisco Next-Generation Network Security

Lesson 2: Introduction and Design of Cisco ASA with FirePOWER Services

Lesson 3: Configuring Cisco ASA with FirePOWER Services

Lesson 4: Cisco AMP for Networks

Lesson 5: Cisco AMP for Endpoints

Lesson 6: Cisco AMP for Content Security

Lesson 7: Configuring and Troubleshooting the Cisco Next-Generation IPS Appliances

Lesson 8: Firepower Management Center

Lesson 1 deals with the fundamentals of Cisco Next-Generation Network Security products, like security threats, Cisco ASA Next-Generation Firewalls, FirePOWER Modules, Next-Generation Intrusion Prevention Systems, Advanced Malware Protection (AMP), Email Security, Web Security, Cisco ISE, Cisco Meraki Cloud Solutions and much more. Omar Santos has done an exceptional job creating short videos, which are a maximum of 12 minutes, he really built up the series with a very informative introduction dealing with the security threats the industry is currently facing, the emergence of Internet of Things (IOT) and its impact and the challenges of detecting threats.

Understanding, Avoiding & Protecting Against Cross Site Request Forgery Attacks

Posted in Web Application Vulnerability Scanners

Understanding, Avoiding & Protecting Against Cross Site Request Forgery Attacks - 5.0 out of 5 based on 4 votes

This article explains what a web browser cookie is and examines how Cross Site Request Forgery work by allowing hackers to intercept and access web browser cookies from unaware users trying to logon to a website to continue their online shopping or access personal online files e.g Dropbox etc. We also explain how we can avoid Cross Site Request Forgery attacks and best security practices to keep our web applications and users safer.

What is a Cookie?

When visiting a website, a cookie (small file) from the website is usually stored on your computer containing information such as login details, items you had in your shopping basket etc. Each cookie is unique to your web browser and website visited, so that the website can retrieve or read the contents of its cookie when revisiting it. What most people are unaware of is that any malicious attacker with access to your computer can use the cookies stored therein to exploit access to websites you have visited earlier.

A malicious attacker may take advantage of this situation by latching on to the authentication cookie the user is sending to the website for initiating an action and then using the credentials to impersonate the user. The attacker uses Cross Site Request Forgery (CSRF) for initiating the attack.

Mechanism of a CSRF Attack

The Open Web Application Security Project (OWASP) Top 10 lists Cross Site Request Forgery which is an attack whereby an attacker uses his or her website to send malicious code to a vulnerable web application in which a user is already authenticated.

Illustration of how CSRF attacks workFigure 1. Illustration of how CSRF attacks work

How to Disable or Enable the Password Recovery Procedure on Cisco Catalyst Switches. Enhance Your Catalyst Switch Security – Protect Configuration Files

Posted in Cisco Switches - Catalyst Switch Configuration

How to Disable or Enable the Password Recovery Procedure on Cisco Catalyst Switches. Enhance Your Catalyst Switch Security – Protect Configuration Files - 5.0 out of 5 based on 2 votes

disable or enable password recovery on Cisco Catalyst switchesOur previous article shows how to perform a password recovery on the Cisco Catalyst switches. This article will now explain how to disable or enable the Cisco password recovery service allowing network engineers and administrators to further secure their Cisco equipment.

The password recovery mechanism is enabled by default which means anyone with physical access to the switch is able to initiate the process and gain access to the switch or stack’s configuration. In some environments this might be a major security concern which is why Cisco provides the option to disable the password recovery mechanism.

In cases where the mechanism is disabled the only option available to gain access to the switch is to delete its startup configuration.

How to Disable or Enable the Password Recovery Service on Cisco Catalyst Switches

Disabling the password recovery mechanism is achieved by using the no service password-recovery command in global configuration mode as shown below:

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