Post by Syed Abdul Haseeb

Scenario: The Routing Loop That Was Not There — Debugging Multi Cloud NGFW Deployments We have all been there. You deploy a virtual Palo Alto Next Generation Firewall (VM Series) in a public cloud transit VPC or VNet to inspect inbound and outbound traffic. Everything looks solid on paper. Then you spin up a new application subnet, update your cloud route tables (UDRs in Azure or AWS Route Tables) to point to the firewall’s trust interface, and asymmetric routing or dropped packets occur. Recently, I was breaking down a scenario involving securing cross-cloud traffic between AWS and Azure environments tied back to an on-premises data center. The challenge? Ensuring that when traffic scales dynamically, Panorama policy groups push consistent zones and security profiles without causing inspection bypasses during a failover event. Three critical design lessons reaffirmed from this architecture: Cloud Native Load Balancing Integration: Relying strictly on static routes to point to a firewall interface is a single point of failure. Integrating an Azure Gateway Load Balancer (GWLB) or AWS Transit Gateway (TGW) with an overlay network keeps traffic symmetric. TCP State Checking: If asymmetric routing does occur during a BGP convergence event over your IPsec tunnels, the Palo Alto will drop the packet out of state. Knowing when to temporarily adjust tcp reject non syn for troubleshooting versus fixing the root path selection is key. Zone Mapping Matrix: Keep your cloud tags mapped tightly to dynamic address groups (DAGs) in Panorama. It saves hours of manual policy creation when dev teams spin up new microservices. To the network architects out there: When design constraints force you into an active active cloud firewall cluster, what is your preferred mechanism for maintaining session symmetry across your NGFWs? #NetworkSecurity #PaloAltoNetworks #AWS #Azure #CloudRouting #NetworkArchitecture #Panorama