Network Problems and Solutions

M. Sc. Juan Carlos Olivares Rojas

juancarlosolivares@hotmail.comjcolivar@itmorelia.edu.mx

http://antares.itmorelia.edu.mx/~jcolivar/

Outline• Preventive Measures

• Diagnostic

• Monitoring

• Main Problems

• Error Solutions

• Computer Network Performance

• Computer Network Accountants

• Maintenace

• Recovering

• Security

Objectives• To know the principal Network Problems

and To Solution these problems.

• Competences:• Diagnostic and Monitoring Services in a

Network.• Maintaining and Performing Services and

Resources over a Network• Securizing and Virtualizing Services

Preventive Measures• The most important thing in an Network is the

Network Management.

• Network Management include the definition of measures to aim to improve the correct function of the Network.

• One of the most important Network Measure is the Network “speed” (Bandwith utilization), other is related with Security, etc.

Diagnostic• Diagnostic is the First Process to detect and

solve Network Problems.

• Exits some Network Diagnostic Tools for automatizing the detection of Network Problems.

• Actually, most of the recently OS have Network Diagnostic Tools to improve and solve problems with the Network.

Monitoring• The term network monitoring describes the use

of a system that constantly monitors a computer network for slow or failing components and that notifies the network administrator in case of outages via email, pager or other alarms.

• It is a subset of the functions involved in network management.

Monitoring• Network Monitor Tools make a serie of services

such as:

• Analyze protocols such as HTTP, FTP, DNS, among other detecting problems and cheking their performance.

• They realize a network tomography and notify all events defined in the configuration process

Monitoring• Most of the implementation of Network Monitors

used the Simple Network Management Protocol (SNMP) for Obtaining the features of a Node in a Network.

• Simple Network Management Protocol (SNMP) is used in network management systems to monitor network-attached devices for conditions that warrant administrative attention. SNMP is a component of the Internet Protocol Suite as defined by the Internet Engineering Task Force (IETF).

Monitoring• It consists of a set of standards for network

management, including an application layer protocol, a database schema, and a set of data objects.

• SNMP exposes management data in the form of variables on the managed systems, which describe the system configuration. These variables can then be queried (and sometimes set) by managing applications.

Monitoring• The isn’t a unique tool who monitor all services

in a Network, this depend of the service such as:

• WebSense/Squid for Web

• IDS (Intrusion Detection Systems) such Snort

• Firewall (IPS –Intrusion Preventing Systems)

• Bandwith utilization such as MRTG, Nagios

• Sniffers: WireShark, Nmap, Ntop

Main Problems

• There isn’t a Network Connection

• There isn’t an Internet Connection

• The Wireless Network disconnect frecuently

• How can we shared an Internet Connection?

• The computer is connected but it can’t see the other or the other computers can’t see that computer

• Some Network Applications don’t run and others runs correctly

Error Solutions

• Explain how can you to solve the problems listed in the past slide?

Computer Network Performance

• Computer Network Performance is the result to monitoring and solving all the events ocurred in a Network.

• It’s an optimization process to guaranted Quality of All Network Services provide in the Network.

• The Network Performance also include the correct admnistration of users.

Computer Network Accountants

• It’s a very important process which consists in registred all the users’ activities in a Network.

• It’s crucial to know what users are doing.

Maintenace• Network Maintenace is the process to improve

the network services for controlling the Network performance.

• Exist three types of maintenace preventive, corrective and performance.

Recovering• Recovering is a process to return the

configuration, information and executing services when a server was failed for diverse reason such as: virus, attacks an other security incidentes.

Security• Network security consists of the provisions

made in an underlying computer network infrastructure, policies adopted by the network administrator to protect the network and the network-accessible resources from unauthorized access, and consistent and continuous monitoring and measurement of its effectiveness (or lack) combined together.

Security• The terms network security and information

security are often used interchangeably, however network security is generally taken as providing protection at the boundaries of an organization, keeping the intruders (e.g. black hat hackers, script kiddies, Trudy, etc.) out. Network security systems today are mostly effective, so the focus has shifted to protecting resources from attack or simple mistakes by people inside the organization, e.g. with Digital Leak Protection (DLP).

Exam 3• Installation, administration and presentation of

one Network Service, for example:

• Snort

• MRTG

• Nagios

• GZIP HTTP Compression

• Squid

• Instant Messenger Service (Jabber)

• Groupware

Exam 3• Exam Guidelines:

• 10 slides maximus

• Software Demonstration (video presentation is suggested)

• Questions of classmates and professor

• Extrapoint for new services (not widely used)

References• Forouzan, B. (2008), Data Comunications and

Networking, 4th. Edition, McGraw-Hill.

• Tanenbaum, A (2004). Computer Networks. 4th Edition. Prentice Hall.

• Kurose, J. and Ross, K. (2007) Computer Networking: A Top Down Approach 4th edition. Addison-Wesley, July 2007.

¿Preguntas?