Subnet routes advertised but not approved blocks expected traffic routing

The tailscaled_advertised_routes metric shows routes that are not reflected in tailscaled_approved_routes, meaning subnet routes have been advertised by a client but not administratively approved. Traffic to these subnets will not be routed.

Compare tailscaled_advertised_routes against tailscaled_approved_routes to identify unapproved routes. Approve necessary subnet routes from the Tailscale admin console. Verify that subnet router configuration matches intended network topology.