How do I specify a serial port in a firewall rule on a WR21? ASY 0 does not work

I am trying to write a firewall rule to pass incoming traffic to the serial port using “routeto” but I can not figure out how to specify the serial port. I know that ASY 0 or Serial 0 do not work. Does anyone know that correct terminology?

Serial / ASY ports are not applicable to the firewall. Firewall is only applicable to IP routed interfaces like Eth, PPP, GRE, etc.

Transport serial ports are configured to “listen” on TCP or UDP ports, for example 4000 for ASY 0. The listening port(s) can be changed via the Transport configuration.

For example, to access ASY 0 your application would need to connect to the mobile IP (or Eth IP) on port 4000. So, no forwarding is required. You will need to allow the applicable port in via the firewall.

Thanks billw1. Understanding that I can not do this through the firewall helps and I understand the connection that you describe.