Asymmetric routing is a common occurrence in network communication where the inbound and outbound traffic flows through different network paths. This usually happens with complex network configurations that have multiple routers, firewalls and other network devices in sequence. In some cases, asymmetric routing is intentional and desirable, while in others, it is an unwanted situation that can cause serious network issues. Asymmetric routing can potentially affect the performance, stability, and security of your network infrastructure. Palo Alto Networks provides numerous advanced security features to help you mitigate asymmetric routing issues. In this article, we’ll explore the key considerations and solutions to mitigate asymmetric routing on Palo Alto Networks.
Key Considerations for Asymmetric Routing on Palo Alto Networks
Assuming you have a complex network architecture, preventing asymmetric routing may be challenging. Consider the following factors that influence the performance and security of your network when designing measures to mitigate asymmetric routing:
Firewall State Information: Firewalls are at the core of network security and help identify, filter and block malicious traffic. However, firewalls rely on state tables to efficiently track the state of incoming and outgoing packets. The state tables map information regarding communication lines in and out of the network. When asymmetric routing occurs, the state tables may generate false positives, discard legitimate packets, or lead to packet drops, causing significant disruptions to network operations.
Traffic Management: Traffic management is an essential aspect of network security and performance. When traffic is distributed unevenly across multiple paths, congestion or packet loss can occur, leading to performance issues. Managing your traffic to ensure load balancing and redundancy across multiple network paths is critical if you must use asymmetric routing.
Firewall Policy Order and Configuration: Palo Alto Networks firewalls are designed to process inbound and outbound traffic according to their policy order. The firewall rules can either permit or deny specific traffic based on IP address, port, service, or application. If the policies are wrongly configured, your Palo Alto Networks firewall may end up blocking legitimate traffic, providing a false sense of security, or allow malicious traffic access to your network.
Mitigation Solutions for Asymmetric Routing on Palo Alto Networks
Palo Alto Networks offers various solutions to mitigate the effects of asymmetric routing. Here are some practical measures you can take to ensure optimal security and performance on Palo Alto Networks:
Route-Based VPNs: VPN tunnels are vital for secure communication across different networks. Palo Alto Networks provides route-based VPNs which are configured to work with multiple dynamic network paths, mitigating asymmetric routing when set up correctly.
Session Pickup: Palo Alto Networks session pickup feature helps manage stateful connections that are lost when asymmetric routing occurs. The feature enables the Palo Alto Networks firewall to track the state of lost connections and quickly resume them when the connection path becomes available.
Destination NAT: Destination Network Address Translation (DNAT) allows you to route or redirect traffic from an external IP address to an internal IP address. DNAT can help optimize traffic and mitigate congestion on multiple network paths.
Conclusion
Asymmetric routing can significantly impact network security and performance, but Palo Alto Networks provides comprehensive security solutions to mitigate its impact. In all cases, it is essential to consider your network architecture when designing solutions to mitigate the threat of asymmetric routing. By implementing the right measures, you can ensure optimal network security and performance. If you face any challenges with asymmetric routing, contact a certified Palo Alto Networks partner to help you secure your network infrastructure.