Chapter 3 outline

1
Chapter 3 outline

• What is network management?
• Internet-standard management framework
• Structure of Management Information SMI
• Management Information Base MIB
• SNMP Protocol Operations and Transport Mappings
• Security and Administration
• ASN.1
• Network management in the real world
• External pressures and constraints
• Time issues
• Tools of the trade

2
Procedures and Supports

• Having good procedures and supports in an
  organization for network management can be some
  of the best tools to have at your disposal.
• Some help in preventing problems (or at least,in
  reducing their severity).
• Others help in problem reporting.
• Others help in solving problems.
• Still others help in cleaning up afterwards.
• An organization with few or no procedures or
  supports in place is likely to be very chaotic
  and frustrating to manage.
• Lets look at some of the industry accepted
  procedures in network management.

3
Policy and Procedures Development

• Network management goes a lot smoother if the
  goals and requirements are set in the policies or
  procedures of the organization.
• These need to be very clear and well defined for
  them to be useful!
• Every organization should have a group or
  committee in charge of setting and reviewing
  these policies and procedures. It should contain
  the following
• Senior management/executives.
• End users.
• And, of course, network managers.

4
Network Documentation

• A set of all network policies and procedures.
• An inventory of all network components.
• Model numbers, serial numbers, and inventory
  tags.
• When and where purchased.
• Warranty information.
• Current location and use.
• Network logical/functional maps.
• Give an overview of the network and how it works.
• The function or service each major component has.
• The dependencies between various components.
• Detail is not important here, but flow is!

5
Network Documentation

• Physical/layout maps.
• Much more detailed than logical maps, so
  youmight need several to explain the whole
  network.
• Shows the location of every network component,
  including all routers, switches, hubs, hosts,
  peripherals, wires, and so on.
• Device and cable labeling.
• Physical labels that identify the devices or
  cables they are attached to in easy to read
  lettering.
• Do not assume that you will remember it is
  better to take the time and properly label things
  so that when they need to be found in a hurry, it
  canbe done easily.

6
Network Documentation

• Additional detailed information.
• Configuration records of all network components.
• Change logs for all system and network changes.
• Problem logs for every problem reported,
  including all intermediate steps and the eventual
  solutions!
• System and network logs of activity.
• Anything and everything else that might proveto
  be useful later on.
• Documenting your network well will the biggest
  favour you can do yourself!

7
Communication

• In any reasonably large network, there will
  inevitably be more than one network manager.
• Good lines of communication are essential!
• Network managers in an organization need to meet
  formally or informally to discuss network
  operations, procedures, problems, and so on.
• If an organization is large enough, it might be
  necessary to hierarchically organize
  communications.
• Form an organization-wide committee with
  representation from each unit that meets
  regularly.
• Each unit meets regularly internally.

8
Communication

• Why is communication so important?
• Fostering awareness of problems affecting others,
  as chances are good you will see them soon too.
  This, of course, includes sharing of solutions!
• Refining and improving practices so that you can
  learn from each others experiences.
• Notifying each other of changes that could
  affectnetwork operations.
• Consulting to assist in solving network
  problemswhen you are having difficulties on your
  own.
• Emotional support!

9
Change Management

• As discussed in the Delta Method, managing
  changes properly goes a long way in helping
  prevent change-related network problems.
• It is important enough to mention again
• All changes must be planned and communicated.
• All changes must be documented.
• All changes must be immediately verified
  afterbeing made to uncover problems as soon as
  possible.
• All changes must have a fallback position, just
  incase something unforeseen goes horribly wrong.
• If managed properly, changes can be made
  relatively painlessly.

10
Maintenance

• Sometimes, parts of your network will need
  planned downtime for regular maintenance
  activities that are not due to some kind of
  network problem. Examples
• Upgrading hardware. Some vendors claim you can
  hot swap though, but do not always trust in
  that!
• Updating systems software. Often, updating
  systems software or patching will require a
  reboot.
• Performance benchmarking. If you need to
  benchmark a system, you need to isolate it from
  regular users.
• Cleaning and other care. Hardware needs periodic
  cleaning to keep operating.

11
Maintenance

• Steps in routine maintenance activities
• Plan the maintenance, and include a fallback.
• Schedule the maintenance with all affected users.
  (If you do not do this, they will not be happy!)
• Disable access to the devices to be taken
  downfor maintenance.
• Conduct maintenance activities.
• Comprehensive testing of devices.
• Post-maintenance communication to all users. Let
  them know if it worked, and when access is
  restored.
• Re-enable access to the devices taken down.
• Follow-up to make sure everything is working
  properly.

12
Redundancy

• Never underestimate the usefulness of replicating
  key network functionality!
• This is good for ensuring performance in
  overloaded situations, and for ensuring continued
  operation in the face of failures.
• Redundancy can take many forms. Examples
• Replicated servers.
• Multiple paths through your network.
• Multiple connections to the global Internet.
• Redundant power supplies.
• Overlapping capabilities in network managers.

13
Backups

• Backups were discussed as a good security
  mechanism to protect against intentional damaging
  or destruction of critical data.
• More times than not, however, backups are used to
  recover from unintentional mishaps.
• This includes
• Accidental deletion of a file.
• Accidental corruption of a file.
• Recovery from a change attempt gone wrong.
• Remember to follow good backup procedures!
• If backups are not handled properly, they will be
  of no use to anyone when the time comes!

14
Help Desks and Call Centers

• If your organization is large enough, help desks
  and call centers can help centralize and organize
  requests for network management services and
  reports of outages or other network problems.
• Help desks deal with people face-to-face.
• Call centers deal with people remotely (typically
  by phone, but also through the Internet).
• They can also provide basic troubleshooting
  services to resolve local problems.
• Once a problem becomes too complex, takes too
  long to solve (gt 15-30 minutes) or expands to
  encompass many users or hosts, problems are
  escalated to back office network managers.

15
Help Desks and Call Centers

• The first line of operators at a help desk or
  call center should be equipped to handle 80 to
  90 of all requests and reports.
• Being equipped means that they have the
  necessary experience, tools, and access
  privileges.
• The remaining requests and reports may need to be
  escalated to a second tier of support with more
  experience and greater privileges.
• These managers also tend to have other duties,
  responsibilities, and projects to attend to.
• They may be with the first line operators,
  orwork behind the scenes.
• Third and fourth tiers may also be necessary,
  depending on the organization.

16
Trouble Tickets

• Trouble tickets are a standard tool used by many
  organizations to help track problems from their
  initial reporting to their eventual solution.
• Collects contact information and problem
  description.
• Carries a priority reflecting the importance of
  the problem contained within the ticket.
• Permits statistical analyses about the kinds of
  requests made, who submitted the requests, and so
  on, that can help in solving the problem.
• When solved, the solution is included with the
  ticket and the ticket is stored away for future
  reference. (If the same problem crops up in the
  future, a ticket search can help greatly in
  solving it!)

17
Troubleshooting Procedures

• When a network manager first receives a problem
  to solve, it is good to have standard
  troubleshooting procedures to follow.
• This includes the analytical methods and
  approaches discussed earlier.
• Sometimes, troubleshooting can be automated using
  scripts or software.
• These can help solve most of the common problems
  that are faced by managers, and are a good tool
  to clear out problems in help desks and call
  centers.
• Most technical users do not like this approach,
  but the reality is that it can solve most of the
  problems that come in! (Remember, these tend to
  be brought forth by non-technical users!)

18
Clear Responsibilities

• Clarifying the responsibilities of network
  managers can help streamline the dispatching of
  problem reports to the appropriate people.
• By properly segmenting responsibilities
• Users know where or to whom problems of different
  kinds are to be reported.
• Managers only need to have detailed knowledge of
  the areas they are directly responsible for, and
  passing knowledge of other areas.
• A separation of responsibilities can provide
  isolation of the various parts of the network,
  for better or worse. (Better changes less
  likely to affect other managers. Worse loss of
  a manager could leave a hole in the network.)

19
Disaster Recovery

• A disaster is a catastrophic event that causes a
  massive outage of network operations.
• Can be an earthquake, fire, tornado, security
  breach, or just some idiot with a backhoe.
• If it has a significant impact on your ability to
  carry out your business, it is a disaster.
• Carry out a detailed risk analysis to see what
  must be protected in such cases.
• Determine how to limit damages, ensure data
  integrity, and continue key operations.
• Get those procedures in place!
• Also, be sure to consider legal ramifications
  and media relations.

20
Prosecution

• When a disaster is man-made, and especially if it
  is intentional (as in the case of a security
  breach), prosecution might be necessary.
• What do you need to do?
• Contact the legal counsel for the
  organizationand get their official opinion and
  position.
• Collect and organize all pertinent information
  (you logged it and kept it all, right?).
• Contact the appropriate authorities. They are
  better equipped now than before, but you still
  may need to do a lot of the tracking down and
  location of the individual(s) involved, if you do
  not already know their identities.

21
Procedure Reviews

• One of the best procedures you can have is one
  that provides feedback and reshapes procedures
  for the better as necessary.
• You have to be prepared to accept it when
  something is not working properly, and you need
  to change it.
• Reviews of all procedures should be done
  regularly sometimes, however, a procedure gone
  horribly wrong should not wait forrevision, and
  should be dealt with immediately.
• Reviews should be conducted by the same committee
  we introduced to help create policies and
  procedures in the first place.

22
Software Tools

• Software tools are very important to a network
  manager in facilitating and automating various
  aspects of network management.
• They come in many varieties
• Big commercial management suites.
• Operating system tools.
• Open source tools.
• Miscellaneous utilities.
• Remember, the more software tools you have, the
  better equipped you are to handling your
  networks problems.

23
Commercial Management Suites

• These are feature-rich packages that provide a
  lot of support for virtually every aspect of
  network management.
• They can also cost a lot, some in the range of
  hundreds of thousands of dollars!
• If you can afford them, they are well worth it
  though!
• Some examples
• HP OpenView
• SunNet Manager
• Optivity Tools UWO CSD has
• Tivoli
• CiscoView/CiscoWorks
• Plus many, many others.

24
Operating System Tools

• Most commercial operating systems include some
  basic tools for systems and network management.
• They are free, in that they come with your
  operating system license (which youve already
  paid for).
• They are not as full-featured as the big
  commercial tools. (A lot of the vendors want you
  to buy one of their expensive packages, if you
  want the features!)
• For example, on Solaris you get access to simple
  tools like perfmeter, netstat, sar and sag,
  admintool, and many, many others.
• They can be quite useful for simple tasks.

25
Open Source Tools

• Surprisingly, there are a lot of really good, and
  really useful tools that are freely available
  under various open source licensing schemes.
• Some good examples
• MRTG Multi Router Traffic Grapher.
• NMAP Network Mapper (port scanner and such).
• Big Brother A tool to watch over you and your
  network. (Only free for non-commercial use.)
• SATAN Security Administrator's Tool for
  Analyzing Networks. There is now a similar tool
  called SAINT with nice features, but it is not
  free.
• Net SNMP A good and free SNMP implementation.
• NTOP A network traffic probe like the Unix
  top.
• SNORT An intrusion detection system.

26
Miscellaneous Utilities

• Do not underestimate the value of simple little
  network utilities in solving network problems!
• Not every problem needs a heavy weight solution!
• Some simple examples
• Using ping to test connectivity and liveness.
• Using traceroute to verify paths through the
  network.
• Using telnet to access various system services
  (and to test liveness when ICMP packets are
  blocked).
• Using ftp to test network performance (how fast
  can a file be downloaded or uploaded?).
• A tool is useful if it gets the job done,
  regardless of its complexity.

27
Experience

• There is no substitute for a lot of experience.
• This can be the most valuable tool at your
  disposal.
• The trick is, how do you get it?
• Most organizations want it before they will hire
  you!
• Some things to consider
• Do not be afraid to experiment with systems and
  network administration at home.
• Take an entry position at a help desk or call
  center as a first line operator, and move your
  way up through the tiers as you gain experience.
• Consider some form of management certification.
• Become a member of SAGE (the System
  Administrators Guild) they provide many useful
  services, as well as certifications.

28
Network Management A Summary

• Network management is a critically important
  aspect of networking, but often sadly ignored.
• Network management, in theory, is not that
  incredibly difficult.
• What is involved with management is well defined.
• Mechanisms like SNMP to support management are
  useful and widely available.
• Network management, in reality, can be quitea
  difficult task indeed.
• External pressures, constraints, and time issues.
• Your best defense is to have a lot of tools at
  your disposal to make life easier.