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:


Code:
# nmap -T4 -F 192.168.1.0-2
 
The router displayed two ports related to the printer service:


Code:
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
 
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!

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