Troubleshoot USB-Printer Connected to Router
I had complained about a flood of error messages being continuously printed out every time a print job was sent to the USB-printer attached to my Asus AC56U router with merlin-378.55_beta1. Yesterday, after I had reverted to the official asuswrt firmware to troubleshoot the printer-sharing feature, I used nmap on my laptop to see the open common ports on the clients on my network:
The router displayed two ports related to the printer service:
Anyway, long story short, I had been using the socket://192.168.1.1:9100 path to the printer; changing the configuration on my laptop (CUPS-server) to point to lpd://192.168.1.1:515/AUTO finally resulted in SUCCESS!
# nmap -T4 -F 192.168.1.0-2
192.168.1.1 Host is up (0.0065s latency). Not shown: 94 closed ports PORT STATE SERVICE 53/tcp open domain 80/tcp open http 139/tcp open netbios-ssn 445/tcp open microsoft-ds 515/tcp open printer 9100/tcp open jetdirect