COMP3122 Network Management

COMP3122Network Management Richard Henson February 2012

Week 2: Installing a Network Server • Objectives • Describe each of the network operating system types used in organisations • Explain how to plan for installation of a network operating system • Effectively install a network server operating system on a computer

Two realistic choices… • A breed of Windows? • A breed of Unix… • Both covered briefly through COMP2122 • Planning for a network covered in a future lecture

Historic Look at Microsoft Network Operating Systems • Microsoft • Windows NT 4 Server (1996) • Windows 2000 Server series (1999) • Windows 2003 Server, Enterprise Server, Data Centre Server, etc…. (2003-7) • Windows 2008 Server, Enterprise Server, Data Centre Server, etc…. (2008-continues)

Available UNIX Network Operating Systems • Various breeds of Unix (e.g.) • SCO Unix • HP-UX • Sun Solaris • Various implementations of Linux • Ubuntu (“humanity towards others”) • Red Hat (redhat.com) • Mandrake (now Mandriva) • SuSe/Novell (now Attachmate)

Which is best? • Nice quote from a blogger: • “Windows people will do windows and Unix people will do Unix, and neither the twain shall ever meet (publicly) and no amount of discourse will eradicate one or the other.”

Which to choose? • Network should serve the needs of the organisation • management of resources could be best suited by a breed of Windows Server or Unix… • Merits of breed of Unix/Linux : • excellent for security, stability and fault tolerance provided that it is set up properly • also good implementation of most network management functions • Merits of Windows 2003/2008 Server: • very easy to administer • excellent online & telephone support • also good implementation of most network management functions

Not just about the software… • Also about understanding of the required functionality of a NOS • and how to configure & control the delivery of that functionality to users • Windows quicker to roll out… • functionality and management easier to pick up • less fuss from a teaching/learning perspective.. • BUT principles of configuration & control apply equally to Unix

Which choice within a Windows Server set up? • Several options presented, to cater for a range of network environments: • Windows Server • Windows Advanced Server • Windows Datacenter Server • Important to establish which is most appropriate beforehand… • http://www.microsoft.com/windowsserver2003/evaluation/features/compareeditions.mspx

Preparation for Installation: client matters (1) • Users work at clients… • smooth connectivity between client and chosen server essential… • Which software on client machines? • which operating system? • which applications?

Preparation for Installation: client matters (2) • Upgrade of server could affect clients • latter may not readily interface as well with more recent versions of the NOS • e.g. very old (pre-2000) Windows clients couldn’t work with active directory • Consequence could be a client upgrade as well

Preparation for Installation: server hardware • NOS delivers functionality • Choice of server os should always be made first… • make sure that CPU, RAM, etc. will be adequate to run the NOS efficiently: • now • in two years time… • As much information as possible needs to be gathered about hardware used in the server: • software tools MAY assist with this process

Hardware compatibility • Choose carefully! Don’t assume anything (!) • you may be surprised • you could well be disappointed! • Microsoft (or any other NOS supplier) should provide a hardware compatibility list (HCL) • all hardware/peripherals checked against the list

Importance of the HCL • Hardware manufacturers may have their drivers on the Windows Server disk • If not,… • (1) hardware is on the HCL, and the manufacturer will have written software you can download… • If the hardware is not on either list, it cannot be used • this DOES happen! • don’t get caught out!!

Preparation for Installation: RAM • Depends on the server configuration chosen… • http://www.microsoft.com/windowsserver2003/evaluation/features/compareeditions.mspx • As regards RAM: • domain controllers will require more… • ECC (72-bit) memory [Error Correcting Code] recd • detects & corrects memory errors

Preparation for Installation: Motherboard • Motherboard options controlled by BIOS settings • BIOS should provide an option to… • support network booting (PXE – Preboot Execution Environment) PXE also very useful for clients - support for RAID devices

Importance of “Plug-and-Play” • Detection and software installation for hardware components automatic • manual install could get the wrong version… • not a good idea! • BIOS settings can be used for plug-and-play and interrupt reservations

Preparation for Installation: Secondary Storage • As much as possible! • allow extra for fault tolerance • Mirroring/duplexing/RAID 5? • Whole network server set-up should also have a backup in another location • essential for network availability • disaster recovery and business continuity are important strategic matters…

Preparation for Installation: media for software • Setup files for NOS usually held on CD: • server BIOS should boot direct from CD-ROM • otherwise, or if CD corrupted, can still use floppy disks to load essential components • Drivers for hardware not on HCL likely to be found separately: • on CD-ROM • on manufacturers website • All non-HCL drivers should be close at hand!

Preparation for Installation: Hard Disk Partitioning • Hard disks must be partitioned before any formatting is possible • Normal to plan for several partitions: • one for booting • one for system files (could be the same as the boot partition) • one for user data • one for applications • Partition data should be backed up…

Preparation for Installation: Choice of File System • FAT32 (share security) or NTFS (file security) • Nowadays, NTFS is increasingly the norm • more efficient management for partitions greater than 2 Gb • on a network, always a good idea to settle on a file system with security control at individual file level • otherwise, users can “run amok”

Client-Server andMicrosoft “domains” • Not the same as DNS domains • Really just another way of saying LAN or client-server network • Domains are “server controlled” • but server needs to be elevated to domain controller status • needs to install “DNS server”

Domains and Active Directory • Active Directory… • logically connects servers together • servers create domains… • can use connections between servers to model the DNS system on a Microsoft network • But things can go wrong… • knowledge of DNS servers required

Internet Domain Naming • An attempt to give logical names to computers directly hooked up to the Internet • First defined back in 1983, through three early RFCs… • 881: The Domain Names Plan and Schedule (revised, 897, 921) • 882: CONCEPTS and FACILITIES (revised, 1034) • 883: IMPLEMENTATION and SPECIFICATION (revised, 1035)

The DNS System • First defined inRFC 1101: • “DNS Encoding of Network Names and Other Types” • First recognisable as x.y.z format through RFC1183: • “New DNS RR Definitions” • Explained including IANA (administration of first level domains) through RFC 1591 (1994) • “Domain Name System Structure and Delegation”

DNS and DNS Zones • The DNS system is hierarchical • A DNS Zone is defined as: “… a portion of the global Domain Name System (DNS) namespace for which administrative responsibility has been delegated” • it refers to the lower level domains logically connected to any one particular root domain (e.g. .us or .com) z y a x DNS entry x.y.z DNS Zone: z Computers within z zone: a, x and y

Naming a Server within a DNS Zone • Windows 2003 Servers promoted to domain controllers are assumed to be part of the DNS • named accordingly within a hierarchy of domain names • DNS Server needs to be installed at this point… • assists Active Directory with domain name record keeping • provides options for storing DNS/IP address pairs

WINS, DNS, and IP addressing • Older versions of Windows used “Windows Internet Naming Service” • look up service including NetBIOS names and corresponding IP addresses • Now, DNS is increasingly replacing WINS: • DNS server manages access to network name/IP address look up

Managing Domain Users • Active Directory installed when server promoted to domain controller • Users gain access via client machines • to even enable user log on, a client machine must have an account in that domain • client details stored in active directory • User must have a domain account • details stored in “Active Directory”… • entry in database of usernames/passwords essential for successful login match

Post-Installation Traps & Errors • Most common problem: • files become corrupt • This will mean that the system boot up process will be suspended indefinitely as the system looks in vain for the missing file

Correcting Installation Errors • Each NOS should have a system to allow recovery from a failed installation • With Windows Server, it is “recovery console” • Such a “recovery” system should allow the system to reboot to at least a command prompt • allowing the necessary file(s) to be re-installed… • The computer should then again boot up satisfactorily

Installing Clients • Will be necessary if: • Existing client software not compatible with server-side or is upgraded for other reasons • Existing client software becomes faulty or will not connect to the domain • New computer to be added to the domain

Automatic Installations • The first server on the network should always be installed manually • However, NOSs allow capabilities for the “automatic” installation of clients • This means that all the questions that are asked by the installation process must be answered on a text file or “script” that can be accessed during the automatic install • with Windows 2000/3 this is known as UNATTEND.TXT

More about Windows “Automatic” Installation • Several possibilities: • RIS (Remote Installation Service) • Windows 2000/3 installation files • “Unattend” Scripts • All provided on a server (RIS server) • Supports PXE (network boot option in BIOS) • SYSPREP • “cloning” or “imaging” tool • Just copy all folders and files directly from a prototype (!)

Configuration of the Network environment • NOS should allow options to add or remove network services and components • If the NOS is really good, such reconfigurations will not even require a reboot! • e.g. breeds of Unix (no registry) • Because the registry needs to be reconfigured and reread, Windows 2000/3 does often require a reboot when new hardware is added…

Upgrading the Server Environment… • Rather than starting again, with a completely new setup, it may be necessary to upgrade an existing facility. • If the network is being upgraded from a previous version, it will be necessary to migrate settings and data into the new environment • essential that such data is safely backed up to tape drive or other safe location before the upgrade begins

Dual Boot Systems • Two different operating systems held on two system partitions • one of the system partitions could (for simplicity) be a floppy disk or USB drive • Most usual with network clients, interfacing with two separate NOSs • always boot into one operating system (boot partition) • then offered (via menu) a choice of system partition to be loaded into memory

Updating Drivers • NOT a good idea to remove a driver from the system until there is evidence that the replacement actually works! • Advised procedure: • disable the existing driver • either: use the Add/Remove Hardware wizard to find and install the new driver • or: restart the computer and allow “plug and play” to find and install the new driver

Ensuring that a driver is “authorised” • Authorised drivers are “signed” by the manufacturer • The “digital signature” can be read by any computer running a recent version of Windows • If a driver doesn’t have an appropriate signature • error message “pop up” appears on the screen • The driver could still be installed, but with no signature there is no guarantee that it will work!

Adding Manufacturers Improvements to the NOS • Networking software continually being updated, optimised, and improved by manufacturers • Improvements released as: • New version of NOS • complete reinstall of system • “Service Pack” • reinstallation of certain components and new features • plugs to recently discovered security holes • hotfixes

Installation of a Service Pack • An “update” command is available • The distribution folder (including URL for Internet downloads) should be included • An option to uninstall the service pack at a later date is included and recommended • A wizard manages the whole process

The End

COMP3122 Network Management