HP JetAdvantage Security Manager 10 Device E-LTU Manual de usuario descargar pdf (Pagina 82)

In JetDirect, the LLC protocol stack was implemented as a separate module from the LLC print

application and was expanded to provide support for protocols other than TCP/IP, including IEEE

802.2 LLC. This allows the LLC print application to use a conventional sockets style interface, with a

special socket type, to access LLC network services. LLC was simplified by using a standard sockets

networking API, minimizing involvement with connection establishment/maintenance, and delegating

the handling of flow control to the protocol stack. In contrast to some of the print applications for

other protocols, LLC does not process or inspect the contents of any data packets that it handles. The

LLC print application supports Locally Administered Address processing.

The Logical Link Layer and the Media Access Control (MAC) layer make up the Data Link Layer. A

major security concern of the data link layer is the Address Resolution Protocol (ARP) process. ARP is

used to resolve known network layer addresses to unknown MAC addresses. ARP is a trusting

protocol and, therefore can be used by hackers for ARP poisoning, allowing them access to traffic on

switched they should not have. If your device still supports the DLC/LLC printing protocol, it should be

disabled if not in use.

Novell (IPX/SPX)

Internetwork packet exchange (IPX) and sequenced packet exchange (SPX) are protocols primarily

used on networks that run the Novell NetWare operating system. These protocols are obsolete.

Internetwork Packet Exchange/Sequenced Packet Exchange (IPX/SPX) was a very popular protocol

suite throughout the 1980’s and midway into the 1990’s. In it’s prime, the IPX/SPX protocol stack

was supported by a number of network operating systems, including Windows. However, IPX/SPX

was mostly thought of as the protocol for Novell Networks and specifically brought forth the practice

of connecting multiple networks together, or internetworking. IPX and SPX connection services are

very similar to TCP/IP and were primarily designed for local area networks. The efficiency of the

IPX/SPX stack contributed to performance that typically exceeded TCP/IP on a local area network.

However, TCP/IP became the industry standard due to its superior performance over wide area

networks and the internet. Novell attempted to support TCP/IP with NetWare/IP by “tunneling” IPX in

IP packets, but complex implementation and performance loss due to the tunneling overhead kept

NetWare/IP from being widely adopted. TCP/IP is now the primary Novell NetWare internetwork

protocol. Although IPX usage has declined dramatically in recent years due to TCP/IP being the

pervasive internet protocol, it wouldn’t be rare to find IPX/SPX still being used in some Windows

environments. In addition, some supported legacy system management tools still support the stack.

Many of the HP Future Smart devices do not provide support for the IPX/SPX stack.

The HP JetDirect implementation of the Novell NetWare Printing subsystem is composed of the

IPX/SPX stack, IPX Direct Mode, Queue Server, Remote Printer, and NetWare Configuration modules.

For many of the Future Smart devices, this capability no longer exists. When IPX/SPX is enabled on

devices that support this protocol suite, the generation of Service Advertising Protocol (SAP) packets

are also enabled. The JetDirect print server name and service type are broadcast via SAP packets,

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HP JetAdvantage Security Manager 10 Device E-LTU Manual de usuario Pagina 82