COMP3122 Network Management

1. COMP3122 Network Management Richard Henson March 2011

2. 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

3. 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…

4. 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

5. 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…

6. 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

7. 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

8. 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…

9. 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

10. 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

11. 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

12. 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)

13. 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

14. Configuration of a Network-Interface 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

15. Configuration of a Network-Interface 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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!

22. 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

23. 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

24. 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

25. 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

26. 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…

27. 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

28. Group Policy Architecture

29. 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

30. 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

31. 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

32. 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

33. 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

34. Thanks for listening