The earliest recollection of this bug is traced back to PAN-OS 10.1.0 - July 22, 2025. Alibaba Cloud runs on a KVM hypervisor and supports two Virtio modes: DPDK (default) and MMAP. If you deploy a VM-Series firewall running PAN-OS 9.0 in DPDK packet mode and you then switch to MMAP packet mode, the VM-Series firewall duplicates packets that originate from or terminate on the firewall. As an example, if a load balancer or a server behind the firewall pings the VM-Series firewall after you switch from DPDK packet mode to MMAP packet mode, the firewall duplicates the ping packets. Throughput traffic is not duplicated if you deploy the VM-Series firewall using MMAP packet mode. 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