How to determine what protocol a printer uses

Question

I'm trying to determine what printing protocol a network printer expects (ipp, http, etc). I've got the hostname and IP address of the printer, and access to a cygwin bash shell and powershell. How do I determine what protocol it's actually using? There's no print server between my machine and the printer as far as I know (but would appreciate tips on how to verify this).

Solution 1

The simplest way is to read the type of the printer and search it on internet. If the printer has a display, you may find out its IP address using its system menu.

Solution 2

You can use a tool like NMAP to perform a port scan of the printer's IP address, to see which ports it is listening for connections on. This will likely give away which protocol it is using, as these will almost certainly be left at the default. For example, port 515 would suggest LPR, and port 9100 would suggest HP JetDirect.

To perform the port scan of the printer with nmap, you can use the following syntax:

nmap -sS 192.168.0.101  

Where 192.168.0.101 is the IP of the printer.

This will give you a list of ports that have been found open. Here's a scan I just did against a Sharp printer in the office:

C:\Scripts>nmap -sS 192.168.65.115

Starting Nmap 6.47 ( http://nmap.org ) at 2014-12-19 11:56 GMT Standard Time
Nmap scan report for 192.168.65.115
Host is up (0.36s latency).
Not shown: 991 closed ports
PORT      STATE SERVICE
21/tcp    open  ftp
23/tcp    open  telnet
80/tcp    open  http
443/tcp   open  https
515/tcp   open  printer
631/tcp   open  ipp
5900/tcp  open  vnc
9100/tcp  open  jetdirect
50001/tcp open  unknown
MAC Address: 78:1C:5A:22:83:70 (Sharp)

Nmap done: 1 IP address (1 host up) scanned in 12.05 seconds  

So here we can see that it is listening for connections on both 515 (LPR) and 9100 (JetDirect). There's also port 631, which is Internet Printing Protocol.

I don't know what port 50001/tcp is supposed to be doing, and apparently neither does NMAP (it shows the service as unknown). So after a brief Google, I have consulted the manual, and found it is the default administration/management interface, used by the proprietary admin tools to manage the printer.
So, we know that this printer supports not just one, but several printing protocols - and these are just the ones that are enabled on the printer. I could have probably learned all this much more quickly if I'd just read the vendor's specs, but it might not have been as much fun.

If your printer shows other ports, you might be able to look them up at IANA's registry of assigned ports, or elsewhere.
You don't have to use NMAP, there are other port scanners available, if you prefer.

Comments

[marsh-wiggle]

Most network printers have an web interface. You may see there which jobs are incomming and what protocol / interface they use.

[Escher]

Unfortunately, I just get the IIS7 logo.

[Kristian]

I can guarantee the printer is not running it's own interface on IIS7. So you're typing the wrong address / IP.

[marsh-wiggle]

Did jou investigate how to access the printer configuration / monitoring? Do jou have the username / password for that?

[Escher]

On the money with the IIS7 comment. I was just given a hostname and used tracert to get the IP. The hostname I was given was wrong. Don't have admin rights on the printer so I can't see the config.

[Escher]

Port scanning! Much better than firing off test pages. I'd be more inclined to use netcat, because I'm more comfortable in a bash shel. nc -z 192.168.0.101 1-whatever