HP JetAdvantage Security Manager 10 Device E-LTU Manual de usuario descargar pdf (Pagina 80)

File Transfer Protocol (FTP)

File transfer protocol (FTP) printing sends print files from a client system to the print device using a TCP

control and data connection. Although FTP provides user name and password authentication, the

credentials are sent unencrypted over the network.

FTP (File Transfer Protocol) is a basic TCP/IP connectivity utility to transfer data between systems. FTP

printing is a way to use FTP to send print files from a client system to an HP Jetdirect-connected

printer. In an FTP printing session, the client connects and sends a print file to the HP Jetdirect FTP

server which in turn passes the print file to the printer. The HP Jetdirect FTP server transfers print files

to the printer but does not interpret them. For proper printing, print files must be in a language

recognized by the printer (such as PostScript, PCL, or unformatted text). For formatted print jobs, you

must first print to a file from your application using the driver for the selected printer, then transfer the

print file to the printer through an FTP session. FTP printing can be somewhat secured via a login and

password, but both are sent unencrypted over the network.

FTP print and download (for firmware updates) were introduced into JetDirect products many years

ago. Certain customers still require this feature in the printers and print server products they

purchase. User access to the FTP server is available using the standard FTP clients that are supported

on most operating systems. The FTP client is an Internet standard for file transfers. The FTP print and

download features were tightly coupled in Jetdirect at one time, but are now decoupled into separate

functionality packages. The “download” functionality is now referred to as “FTP Firmware Update”.

Both FTP print and download use two TCP connections to transfer a file, just as in standard FTP. The

“control” connection is established through the well-known TCP port (21) that passively awaits a client

connection. Once connection is established, it will stay active the entire time that the client

communicates with the server. The second connection, a “data” connection is created each time a

file is transferred between client and server.

Security vulnerabilities related to HP Jetdirect FTP (and FTP in general), have existed for almost as long

as FTP functionality itself. FTP servers are prone to remote denial-of-service (DoS) vulnerabilities that

can affect device access for legitimate users. DoS attacks such as buffer overflows, rogue commands

and malformed packets have been historically known to crash FTP print servers or destroy firmware.

If FTP printing is not required in the environment, this protocol should be disabled. If required on

legacy HP devices where FTP print and download are coupled together, only enable FTP for the

firmware download, then disable when complete.

AppleTalk

AppleTalk is an obsolete protocol used by the original Apple networking. Apple no longer supports

AppleTalk.

Released by Apple in 1985 with the original Macintosh, Appletalk was a protocol suite that provided

addressing, routing, data stream services, naming services and file/print sharing. Appletalk

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HP JetAdvantage Security Manager 10 Device E-LTU Manual de usuario Pagina 80