Network Management

1
Network Management

• Roy H. John
• Cisco Networking Academy
• Youngstown State University

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Network Documentation

• The first and most critical component for a good
  network is documentation.
• Documentation is the most talked about and least
  performed task in a network.
• Documentation also includes 
• diagrams that indicate the path of the physical
  wiring layout 
• the type of cable 
• the length of each cable 
• the type of termination for the cable 
• physical location of each wall plate or patch
  panel, and
• a labeling scheme for easy identification of each
  wire.

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MDF and IDF Documentation

• This document contains a physical and logical
  layout of the Main Distribution Facility and all
  of the Intermediate Distribution Facilities in
  the network. I
• It includes the physical layout of rack mounts,
  Aux. equipment, and servers in the distribution
  facility.
• It also includes patch panel labels to identify
  cable terminations.
• Identification and configuration details of all
  equipment located in the distribution facility.

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Server and Workstation Doc.

• Server and workstation configuration details are
  to be filled out about each host attached to the
  network. 
• Information on these sheets is standardized and
  contains such things as make and model of
  computer, serial number, floppy drives, hard
  drives, DVD/CD-ROM drive, Sound and network
  cards, the amount of RAM, and any other physical
  details of the computer.
• This information also includes configuration
  details about the computer. The IRQ, DMA and Base
  memory address configuration details of the
  peripheral cards. 
• Lastly this document contains the physical
  location, user, and network identification (IP
  address, MAC address, Subnet, Topology)
  information about the computer.
• Also, include purchase date and warranty
  information in this document.

5
Software Documentation

• A listing of standard and special software used
  on each machine in the network.
• The standard configuration installation detail of
  each software package.
• This list includes operating system and
  application software.

6
Maintenance Records

• It is also valuable to keep a list of all repairs
  that have been done to all equipment included in
  the network.
• This will help an administrator predict possible
  future problems with existing hardware and
  software.

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Security Documentation

• This document not only includes "soft" security,
  such as user rights, password definition, and
  firewall support, but also physical security.
• Physical or hard security includes things as
  simple as identifying how the MDF and IDF's are
  locked, who has access to these rooms and why,
  how the hosts are protected (security cables -
  alarms), and who has physical access to the
  system.

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User policies

• They contain how the users can interact with the
  network.
• These policies include what is and what is not
  permissible on the network.
• It should also include what the consequences of
  violating user policies will be.
• As a network administrator, you want to create
  the most secure and functional network possible
  for your company.
• Make sure network policies don't conflict with
  company policies or limit the users access to
  necessary resources. 

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All Documentation

• The information recorded in the documents
  mentioned creates the network documentation set
  for your system.
• This documentation set will allow maintenance and
  upgrades to the network in a more orderly
  fashion.
• This documentation will give the administrator a
  starting place to return to if an upgrade goes
  wrong or if there is a need to recover from a
  network failure.
• One last point about network documentation is
  that it continuously needs to be updated with the
  latest upgrades and configuration changes to the
  network.
• If this doesn't happen, the documentation will
  not have a great deal of relevance to your
  current network implementation.

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Network Problems and Solutions

• Common Design add-ins that can

.save your butt someday!
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Data Recovery

• There are multiple methods to prevent data from
  being lost. Usually there is more than one method
  being used at the same time to protect the data.
• Three popular data protection methods are
• Tape Backup
• Fault tolerant disk configurations
• Uninterruptible Power Supplies (UPS) to prevent
  equipment shutdowns during electrical power
  outages.

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Data Recovery - continued

• Tape backup is the process of duplicating all
  stored data to magnetic tape. The reason that
  tape is used is its cost and capacity. Tape
  cartridges are much less expensive and contain
  much greater storage capacity than comparable
  removable hard disks.
• To allow for the complete backup to occur most
  efficiently, different types of backups have been
  developed. Most of the backup types work with a
  flag or switch called the Archive bit. The
  archive bit is stored with a file and turned on
  whenever that file is created or modified. This
  flag tells the backup process if the file needs
  to be backed up or not. If a file is stored to
  tape during the backup process, normally, the
  flag is turned off saying that the current file
  is backed up to tape.
• Most companies recommend that tapes and backups
  be stored in some type of fire safe, or they are
  taken off premises in case of fire or water
  damage.

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Types of Backup operations

• Full backup All files on the disk are stored to
  tape and the archive bit for all files is set to
  off.
• Incremental backup Backs up all the files that
  have been created or modified since the last full
  backup.
• Differential backup Backs up all the files that
  have been created or modified since the last full
  backup.
• Copy backup Backs up user selected files to
  tape. This backup also does not reset the archive
  bit to off.
• Daily backup Backs up only the files that are
  modified on the day of the backup. This backup
  also does not reset the archive bit to off.

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Redundancy Methods

• RAID 0  Stripes data across multiple disks, no
  parity, so there is no redundancy.
• RAID 1  Disk mirroring (disk duplexing) writes
  data to two identical partitions on separate hard
  disks thus creating an automatic backup. Disk
  duplexing uses two hard disk controller cards as
  well as two hard disks to prevent the controller
  card as being the single point of failure for the
  system as in disk mirroring.
• RAID 2  Writes data across multiple hard disks,
  with error checking. This system is not used any
  more because it requires expensive disk
  modifications to work.

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Redundancy - continued

• RAID 3  Stripes data one byte at a time and has a
  dedicated parity drive. A good, but expensive
  redundancy choice.
• RAID 4  Stripes data one sector at a time and has
  a dedicated parity drive. An expensive redundancy
  choice that is very slow on data writes to the
  disk.
• 6. RAID 5  Stripes data and parity across
  multiple disks (at least three for RAID 5). By
  mixing the parity across all of the disks, a
  separate parity disk is not required and yet full
  data redundancy is achieved. Data writes to the
  disk are still slow, but the cost isn't so high.

16
Power Conditioning

• Isolating transformer Controls voltage spikes
  and high frequency noise.
• Regulators Maintains a constant output voltage
  despite changes in the power line's voltage over
  a long period of time.
• Line Conditioner This is a regulator with an
  isolating transformer built in.
• Uninterruptible power supply Basically this is a
  battery charger that charges a battery that in
  turn powers the computer.  

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Software Viruses

• A virus sole purpose is to disrupt the operation
  of a computer or a network.  
• A Worm is a program that propagates itself across
  computers, usually by creating copies of itself
  in each computer's memory.
• A Virus is a program that "infects" computer
  files (usually other executable programs) by
  inserting in those files copies of itself.
• A Trojan Horse is a destructive program disguised
  as a game, a utility, or an application. When
  run, a Trojan horse does something devious to the
  computer system while appearing to do something
  useful.

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Server Administration
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Types of Networks

• There are two types of networks that network
  administrators need to be aware of.
• Peer-to-Peer
• Client-Server networks.

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Peer to Peer Networks

• The peer-to-peer network is also known as a
  workgroup network.
• Advantages are
• It is designed for small numbers of workstations
  Microsoft recommends no more that 10 users in a
  peer-to-peer network.
• It is cheaper to create and operate than a
  client-server network.
• It allows users to control their own resources.
• It does not require a dedicated server.
• No additional software is required, besides a
  suitable operation system

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Peer to Peer - continued

• Disadvantages Are
• No central point of management is provided and
  each user must create ID's for each user that
  shares resources on their machine.
• If a shared workstation is turned off or
  otherwise unavailable, those resources are not
  available.
• The last disadvantage was mentioned before, that
  is if there are more than ten users or if the
  network will grow to more than ten users in the
  next year, a peer-to-peer network is not a good
  choice

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Client Server Networks

• The advantages of client-server networks are
• They provide a centralized point of user,
  security, and resource management.
• Dedicated servers can be used to more effectively
  provide specific resources to clients. They also
  provide access to all allowed resources with one
  network ID and password.

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Client Server - continued

• The disadvantages are that there is now a single
  point of failure in the network.
• If the server "goes down", all server resources
  are unavailable to the clients.
• Network operation and maintenance now require
  specially trained personnel to maintain the
  network. This along with special network software
  and hardware add greatly to the cost of
  operation.

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Open discussion on network troubleshooting
6 Steps
1. Identify network/user problem. 2. Gather data
about network/user problem. 3. Analyze data to
come up with a possible solution to the problem.
4. Implement solution to network to attempt
correction to the system. 5. If the problem
isn't resolved, undo previous changes and modify
data. 6. Go to step 3