Transcript presentation7

COMP3122
Network Management
Richard Henson
March 2011
Week 7 – Managing
Network Printing
 Objectives
– Identify all possibilities for allowing a printer
to be used by network users
– Explain how a print queue and spooler
work
– Manage user needs in terms of printing
priorities
Whole Session on Printers?

Until you come to manage a network,
the amount of time spent on printer
related problems will not be
appreciated:
– so much can go wrong…
– and frequently does!

Good news for network administrators…
– printer control and troubleshooting software is
much improved…
– and people print less…
Printer Topologies

A printer can be attached to a network
in a number of ways:
– as a standalone network device
» needs its own network card
– connected to a user workstation which can
allow network access via a share
– connected directly to a network server,
which provides the print services
Local Printing

A network user may have their own computer
and printer
– the print device will be connected via a local port
e.g. LPT1 or USB
– stills need to be configured on that machine for
local printing

Installation and configuration is best left to the
wizard (if there is one…)
– however, even the wizard won’t be able to help if
the driver for that printer is not available…
Sharing a Local Printer using
UNC names

Once a local printer is working, the user
may wish to make it available to other
network users
– achieved on Microsoft networks by setting
up a printer share
– the share can be made available to other
network users via a Microsoft UNC
(Universal Naming Convention) pathname
» e.g. \\printserver\printname
Limitations on
Network Printer Sharing

To send print data, a communications
channel needs to be opened between
the sending computer and the print
controlling computer
– channel takes up resources…
– and stays open?
» in Windows printing, channels generally stay open
for the rest of the user session
» if many users print it can take a lot of bandwidth
Limitations on
Network Printer Sharing

Problem:
– usually a limit on channels open
simultaneously on a workstation
(e.g. 2000 Professional – 10 users)
– only overcome by using server software
(e.g. 2000 Server) to manage the
connections
– means making the computer connected to
the printer a network server
» security implications if not managed
appropriately…
Microsoft Network Printing
The component that does the printing is
referred to as a print device
 The software object on the IP address
based device that controls the print
device is called the printer
 There can be several print devices
connected to a single printer, through
the use of different ports

Mechanism for Printing I

Before a document is even sent for
printing:
– the required printer driver software
needs to be located
– the relevant type of printing device
needs to be identified
– the driver software needs to format the
document for printing as a “print job”
– the print queue (a folder) needs to be
ready to receive the print job
Mechanism for Printing II

Once the formatted document arrives at the
IP address of the relevant device for
containing the software “printer”
– printing priority needs to be identified
– the document needs to be put into an appropriate
place in the print queue as a print job

A lot of print jobs creates a large queue…
– plenty of disk space needs to be available on that
hard disk drive/partition
Configuration of a
Network Printer I

Hardware requirements:
– plenty of RAM
» a lot of processes will be running concurrently
– plenty of hard disk space
» requested print jobs will need to be queued

Software Requirements:
– operating system that will support the
expected volume of network printing
– the appropriate printer driver(s)
Configuration of a
Network Printer II

Administrator privileges required…
– assuming there are sufficient LPT ports
– several printing devices can be configured to work
on the same computer
» assuming that appropriate device drivers are available

Drivers also need to be installed…
– for each type of client operating system (e.g. XP,
Vista, 7, apple?) involved in sending print jobs
– need to be available to client machines when they
first connect to the network printer
Configuration of a NetworkInterface Print Device


Avoids tying up a computer as a “printer”
Two possibilities:
– EITHER… the device is intelligent (e.g. HPJetDirect)
» in which case it should be automatically detectable by the NOS
– OR… it is just a printer with network card

In each case, an IP address needs to be allocated
– if DHCP is running on the network
» printing will be managed by the DHCP server
» an IP address lease can be assigned as soon as communication is
established
Configuration of a NetworkInterface Print Device

As with any other network printer…
– server needs to create a logical port to send print
jobs to

In this case, the port will point to the IP address
of the network connection to the printer
– assuming that the network protocol is TCP/IP
– if network uses active directory, it will be
» within the scope for managing printers with active directory
Connecting to a Network
“Printer”/Print Device

Each network print device also has its own UNC
name
– should be stored in a database on a Domain
Controller
– database should be accessible to any computer on the
network

The local computer can use a configuration
wizard to link to the UNC name
– any required drivers should be accessed and installed
from the print server
SPOOLing



Sequential Processing Operations OnLine
All requests for printing on a particular print
device will be stored in a directory on the
relevant print server
Generally known as a spooler:
– once upon a time (e.g. 1960s, 70s, 80s) the print
jobs would be “spooled” onto magnetic tape
– would be printed at a later date
» e.g. overnight

Nowadays, the “spooler” is the folder that
holds print jobs in the print queue
Setting Printing Priorities




Lowest priority = 1
Highest priority = 99
Multiple logical printers need to be created for
a single print device
The logical printers can then be set to have
different priorities:
– different groups of users point to different logical
printers
– users send different priority documents to different
logical printers
Print Queue
Simply an ordered list of print jobs
 Ordering of jobs to be serviced occurs
according to:

– time received by the spooler
– printing priority of the user sending that
print job
Managing Print Queues

W2K has automated Queue Management
– print jobs will get processed in order of priority

BUT… if a high priority print job gets stuck for
some reason
– no other print job will be able to take precedence

Manual queue management therefore
needed so the faulty print job can be
deleted/bypassed
Printer Hardware Failures

Many printer problems are hardware related:
– out of paper
– paper jam
– printer accidentally switched off

In each case, the print job will:
– get through to the print server
– be added to the queue
– then gets stuck in the queue!

Result: could be a very long queue!
Printer Queue Manager



Need someone who can step in and:
– sort out the printer hardware problem
– log on to the print server with sufficient status to
manage the print queue
Dangerous to give Administrative access to a user!
W2K has a user group called “Print Operators”
– any user can be added to this group

Print Operators:
– HAS sufficient access to print server to manage print queues
– DOES NOT give sufficient access to change printer settings
Setting up a Printer Pool

Required:
– one logical printer interface
– connected to two or more print devices



Print devices can local or network-interface
Print jobs go to the first available print device
Advantages:
– decreases wait time on the print server
– multiple print devices administered from one logical
printer
Assigning Logical
Printer Permissions

NOS should have:
– a range of printer permissions
– a smaller number of permission levels

e.g. Windows printing uses:
– nine types of permission (!)
– three levels of permission:
» Print
» Manage Documents
» Manage Printers
Managing Printing
across the Internet


Print jobs submitted via browser
Can be used for any printer connected to the
Internet
– all that is needed is the URL
– or the IP address

With Windows printing, the web browser can
be used to provide the interface to:
– view print queues
– manage logical printers
Active Directory and Printing

Active Directory uses IP addresses to locate
network devices
– DNS names also pinpoint network devices
– and UNC names can identify print devices linked to
a “printer” computer, via its IP address

Printer settings of all relevant devices on the
network can be stored in Active Directory
– therefore AD is the most convenient way to
manage configurations of printing devices…
Group Policies and Printing

As previously stated, Group Policy
– is one of the top reasons to deploy Active
Directory because it allows you to manage user
and computer objects
– is an infrastructure that allows an administrator to
implement specific configurations for users and
computers

Group Policy settings are contained in Group
Policy objects (GPOs), linked to Active
Directory sites, domains, or organizational
units (OUs)
– settings are then evaluated on the target machine,
using the hierarchical nature of Active Directory
Group Policy Architecture
Location of Group Policies


Group policies held in templates (GPT) on
domain controller
Stored in the GPC (Group Policy Container)
– found in Active Directory on each domain
controller in the domain
– within the /Sysvol folder
» in the /Policies sub-folder

Accessed most easily using GPMC
Group Policy Objects
and Printing


All Group Policy settings are contained in Group
Policy objects (GPO)
GPOs associated via GPTs with Active Directory
containers e.g.
– Sites
– Organizational Units
– Domains

Most of Active Directory printer-related settings can
be enabled or disabled by using Group Policies
– this maximizes Active Directory’s usefulness for controlling
printing activities
Active Directory & Printer Locations I
The basic principle is that a printer’s
location can be associated with a
particular subnet
 Once defined in this way

– the “location” will pre-populate for the
printers

First step:
– map out the locations…
» a location is a string separated by / character…

e.g. Europe/London/ParkLane/Accounting
Active Directory & Printer Locations II

Three rules for naming locations:
– any single level cannot be more than 32 characters
– maximum of 256 levels
– maximum length of the entire location is 260
characters

Components of location names can occur in
any order
– city usually at level 2 in the location name but could
also be level 3 e.g. NorthAmerica/Ohio/Chicago
– allows flexibility of design of location codes
Setting up Printer Locations

Configuration uses active directory
– through “active directory sites and
services”
» associate name with subnet
– and “active directory users and
computers”
» pre-populate search location
Thanks for listening