Normally when a printer reboots on a network like this it means there is a bad print job in one of its queues. Since you appear to not have a print server then managing all the individual queues on your user machines will be difficult.
Something appears to be attempting to communicate with your printer when it is network connected. It may not be an end user but may be a network service or application. I am not familiar with the Ubuntu command you posted here but I would assume you are not capturing the actual communication that is causing your printer to reboot.
One suggestion would be to move your printer to a different ethernet jack and assign it an alternative IP Address. See if the printer will still be targeted with an alternative network configuration. If the printer behaves the same way on an alternative IP Address then I would assume there is a glitch on the printer. If the printer can co-exist with your enviornment on a different IP then there is something else chatting on your network to the original IP.
You should also make sure your printer has the latest firmware installed.