Aviatrix Kubernetes Firewall vs Flannel

Aviatrix Kubernetes Firewall governs traffic entering, leaving, and moving between Kubernetes workloads across clusters and environments. It applies Zero Trust controls at the cloud network layer, outside Kubernetes clusters, so deployment does not require sidecars, agents, CNI replacement, or application changes. Policies can target pods, namespaces, services, and labels using Kubernetes-native identities. A centralized control plane manages policy across multicloud and multicluster environments, with automation options including Terraform, Kubernetes custom resource definitions, GitOps, and policies in Kubernetes manifests. Supported environments include AWS, Microsoft Azure, Google Cloud, and on-premises deployments, including EKS, AKS, and GKE. The product offers traffic visibility, observability, and anomaly detection, along with distributed firewalling, threat prevention, URL filtering, egress control, micro-segmentation, TLS decryption, DNS firewalling, and advanced NAT for overlapping address ranges. It can use a shared security model for containerized and legacy VM workloads. There is no free plan.

Flannel is a free network fabric for containers designed for Kubernetes. A small flanneld agent on each host allocates a subnet lease from a configured address space, then forwards packets between hosts using a selected backend. Documented choices include VXLAN, host-gw, WireGuard and UDP, with VXLAN recommended. WireGuard encapsulates and encrypts packets using the in-kernel WireGuard implementation. Network configuration and subnet allocations can be stored in the Kubernetes API or directly in etcd. The project documents Kubernetes and Docker deployments, with Linux and Windows build instructions. Flannel does not enforce network policies itself, though its Helm chart can deploy a Kubernetes SIGs network policy controller alongside it. It runs as a privileged daemonset with access to the host network, so the security policy advises least privilege and keeping it updated. Security fixes are maintained for the latest release only, and the backend documentation says not to change a selected backend at runtime.