Robot is behind carrier-grade NAT

Where this comes from

This is the page <seyd-connect-error> links to for the diagnosis class robot-cgnat. The class is chosen by classify() in @seyd/web from the robot’s NAT report and the failure reason; see Reachability for how the report is built.

The robot’s router got a private address from its carrier (usually 100.64.0.0/10, sometimes 10.0.0.0/8), so there is no public address on which the robot can be reached, and no port mapping can create one. With no IPv6 either, a direct connection from a browser is impossible from this network.

What to do, in order of how often it works

1. Enable IPv6 on the SIM or APN. Most carriers offer it; many need it switched on in the router’s cellular settings or on the APN profile. With a global IPv6 address the robot announces an IPv6 candidate, and the only remaining question is the router’s IPv6 firewall (see Robot IPv6 is firewalled).
2. A SIM with a public IPv4 address. Business and M2M plans usually offer one, sometimes under “static IP” or “public APN”. Seyd then port-maps or you forward UDP 4433 once.
3. Put the robot behind a router that supports PCP or UPnP on a non-CGNAT uplink, such as a site’s fibre or DSL connection.

What does not help

Port forwarding on the robot’s own router. It forwards from an address nobody outside can reach.

Meanwhile

If the robot allows the relay, the pilot drives through it and the HUD says so. Starlink is a common case of this class; see Starlink.