CGNAT / NAT Behavior Checker

Enter your carrier NAT type, NAT behavior (full cone, restricted cone, port-restricted cone, symmetric, double NAT), VPN configuration, and application type to understand session timeout risk, VPN keepalive requirements, and application impact. Produces a Low / Medium / High risk label, per-concern flags, VPN-specific advisory, recommended keepalive interval, NAT-T/IPsec compatibility verdict, and PAT/overload behavior notes.

CGNAT is pervasive on cellular networks and is often the root cause of VPN drops, NAT table timeouts, and broken ATM/POS sessions. This tool converts your configuration into a plain-English risk assessment with actionable recommendations.