Have you ever experienced a hardware or link failure in your network? If so, you know that without high availability, the consequences can be catastrophic. Firewalls, in particular, play a critical role in managing connections to the Internet and ensuring network security.
In this article, we will explore how high availability works on Palo Alto firewalls and how it can be implemented to ensure uninterrupted network connectivity. Palo Alto firewalls offer two options for high availability: active-passive and active-active.
Contents
Active-Passive High Availability
The active-passive configuration is the simplest way to deploy high availability. In this model, one firewall is actively analyzing and passing traffic, while the second firewall remains in a passive state, ready to take over in the event of a failure. The passive firewall synchronizes information, such as firewall configuration and session data, from the active firewall.
If the active firewall fails, the passive firewall seamlessly takes over, ensuring uninterrupted network connectivity. This configuration is ideal for scenarios where the passive firewall does not need to process a significant amount of traffic.
Active-Active High Availability
In the active-active configuration, both firewalls actively process traffic simultaneously, sharing the load between them. This configuration requires both firewalls to be powerful enough to handle the entire network traffic load. If one firewall fails, the other firewall takes on the additional traffic.
Implementing active-active high availability requires careful consideration of how traffic is distributed between the firewalls and how network pools are managed on each device. It is essential to ensure that traffic is evenly balanced between the firewalls to avoid overwhelming one firewall with traffic.
Configuring High Availability on Palo Alto Firewalls
To configure high availability on Palo Alto firewalls, specific links called control links and data links are established between the firewalls. These links enable the synchronization of control plane and data plane traffic, ensuring seamless failover in case of a failure.
Control links facilitate the exchange of control plane traffic, including heartbeat messages, state information, and routing table synchronization. Data links are used for sharing data plane traffic, such as session synchronization, forwarding tables, IP set, and other operational information.
It is also important to set priority levels for each firewall in both active-passive and active-active configurations. The firewall with the higher priority level becomes the active firewall. Preemption can be enabled to automatically switch to a firewall with a better priority if a failed firewall is replaced.
FAQs
Q: Can I use regular ports for high availability if my firewall does not have dedicated control and data links?
A: Yes, you can configure regular ports for control and data links if your firewall model does not have dedicated ports for high availability. It is also possible to use the management port for control links in some cases.
Q: How can I ensure traffic is evenly balanced between the firewalls in an active-active configuration?
A: There are several methods to evenly distribute traffic between firewalls in an active-active configuration. Options include layer three routing, layer two floating IP addresses with load sharing, or using an external hardware load balancer. Choose the method that best suits your network requirements.
Q: What happens if a packet arrives at the wrong firewall in an active-active configuration?
A: In an active-active configuration, a three link is used to redirect packets to the correct firewall. The three link is only necessary for active-active configurations.
Conclusion
High availability is a critical aspect of network infrastructure, especially for firewalls. Palo Alto firewalls offer both active-passive and active-active high availability configurations to ensure uninterrupted network connectivity. By understanding the options and configuring high availability correctly, you can protect your network from failures and ensure smooth operations.
To learn more about Palo Alto firewalls and their high availability features, visit the official Techal website.
Note: This article provides a general overview of high availability on Palo Alto firewalls. For specific configuration details and implementation guidelines, refer to Palo Alto Networks’ official documentation.
Image Source: Palo Alto Networks
