firewall
Next-generation firewall insertion and NVAs
Azure vWAN does not support site-to-site VPNs with Cisco FTDv NVAs per official docs. No successful deployments in vWAN hubs. Covers limitations, issues, troubleshooting steps, and alternatives like native gateways.
Learn why iptables -C command fails to recognize NAT rules and how to properly verify iptables NAT rules using the correct syntax with -t nat option.
Master iptables rules for WireGuard wg0: drop all incoming packets except UDP port 51821. Why ACCEPT+DROP beats single negated rule. Avoid pitfalls like negation logic, rule ordering, connection tracking, INPUT vs FORWARD chains.
Troubleshoot MikroTik routing issue with ISP /25 subnet: can't ping between public IPs despite external access working. Enable proxy ARP, check ARP tables, routes, and firewall for MikroTik ping fixes.