Posted by & filed under CompTIA A+, MICROSOFT MTA O/S.

A bad computer motherboard or CPU can cause an assortment of different issues on your computer. Below are just a few of the possible issues you may encounter. It is important to remember that the issues below can also be caused by more than just a bad motherboard and CPU. Read more »

Posted by & filed under CISSP.

  • Quantitative Analysis (ALE=SLE x ARO)
    • ALE = Annualized Loss Expectancy (A dollar amount that estimates the loss potential from a risk in a span of year)
    • SLE = Single Loss Expectancy (A dollar amount that is assigned to a single event that represents the company’s potential loss)
    • ARO = Annualized Rate of Occurrence (Frequency of a threat expected to occur in a period of one year)

    Read more »

Posted by & filed under CISSP.

 

  • After-action review (AAR): a detailed examination of events that occurred from incident detection to recovery
  • Identify areas of the BC/DR plans that worked, didn’t work, or need improvement
  • AAR’s are conducted with all participants in attendance
  • AAR is recorded for use as a training case
  • AAR brings the BCP/DRP teams’ actions to a close

Read more »

Posted by & filed under CISSP.

Computer as incidental to other crimes

  • Involves crimes where computers are not really necessary for such crimes to be committed. Instead computers facilitate these crimes and make them difficult to detect.
  • Examples of crimes in this category may include money laundering and unlawful activities on bulletin board systems.

Read more »

Posted by & filed under CISSP.

 IPSec

  • IPSec is an architecture or framework for security services for IP networks. It works at the Network Layer of the OSI Model.
  • It is actually a standard for secure data transmission.
  • It provides mechanisms for authentication and encryption.
  • Defined by RFC 4301 and carries a set of functions, it is mandatory in IPv6.
  • IPSec allows the use of several different protocol options for each VPN feature.

 

 

IPSec Encryption:  IPSec supports several variations of encryption algorithms, such as, AES.

1.Sending device feeds the original packet and the session key into the encryption formula, calculating the encrypted data.

2.The sending device encapsulates the encrypted data into a packet, which includes the new IP header and VPN header.
3.The sending device sends this new packet to the destination VPN device.
4.The receiving device runs the corresponding decryption formula, the same value as was used by the sending device to decrypt the data.

 

 

IPSec KEY Exchange:  IPSec uses a dynamic key exchange called Internet Key Exchange (IKE) – defined by RFC 4306. IKE uses a specific process called the Diffie-Hellman (DH) key exchange protocol.

DH allows the devices to make up and exchange key securely.

 

Internet Key Exchange (IKE)

  • IKE is the protocol that IPSec uses to negotiate and establish authenticated keying materials for security associations (SA’s).
  • IKE came out of the combination/hybrid of two protocols namely, Internet Security Associations and Key Management Protocol (ISAKMP) and the Oakley Key Management Protocol.
  • A security association (SA) is an agreement between the communicating peers (devices) on factors such as IPSec protocols (AH & ESP), mode of operation of the protocols (transport or tunnel), cryptographic algorithms, cryptographic keys, and the lifetime of the keys, among others.
  • SA parameters are stored in the Security Association Databases (SADs).

 

Security Associations (SAs)

  • Defines the mechanisms that an endpoint will use to communicate with its partner.
  • All SAs cover transmission in one direction only.
  • A second must be defined for a two-way communication.
  • Defined SA mechanisms include encryption and authentication algorithms, and usage of protocols such as AH and ESP.

IPSec KEY Authentication and Message Integrity:

Authentication here generally refers to the process by which a receiving VPN device can confirm that a received packet was really sent by a trusted VPN peer.

Message Integrity , sometimes referred to as message authentication, allows the receiver to confirm that the message was not tampered with in transit.

 

Hashed-based Massage Authentication Code (HMAC) is used. The sending device computes a has and stores the result in the VPN header. The receiving device re-computes the hash using a shared key, and compares the value with the value listed in the VPN header. If it matches then receiver knows message did not change.

Function Method Description
Message integrity HMAC-MD5 Uses a 128-bit shared key, generating a 128-bit hash value
Message integrity HMAC-SHA SHA uses different key sizes – 160, 256, 512. Considered better than MD5 but has more overhead.
Authentication Pre-shared Keys Both VPN devices must be preconfigured with same secret key
Authentication Digital Signatures RSA is used for encryption.

 

 

 

IPSec Protocols

The ESP and AH Security Protocols – IPSec defines these two security protocols with each defining a header.

 

 Encapsulating Security Payload (ESP) – defines the rules for performing authentication, message integrity, encryption and anti-replay. ESP can be used with or without AH.

 

Authentication Header (AH) – supports authentication and message integrity. AH does not offer any encryption services.

 

IPSec Modes

Endpoint communicate with IPSec using either transport or tunnel mode.

 

  • Transport Mode –  encrypts only the IP payload. This mode is mostly used for end-to-end protection, for example, between a client and server.
  • Tunnel Mode –  encrypts both the IP payload and headers. Tunnel mode is often used between networks, such as with firewall- to-firewall VPN’s.

 

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Posted by & filed under CISSP.

WANS and Their Components

Wide area networks (WANs) are considerably different than LANs. Organizations usually own their own LANs, but WAN services are typically leased; it’s not feasible to have your network guy run a cable from New York to Dallas. Read more »

Posted by & filed under Exin ITIL.

 [bs_icon name=”glyphicon glyphicon-chevron-right”] The Role of Measurement

Measurement plays a critical role within ITIL®, both as a part of Continual Service Improvement, but also within Service Level Management and as an essential part of all processes. Measurements can be used for four basic purposes as shown below: Read more »

Posted by & filed under Exin ITIL.

Service Operation

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Overview

The Service Operation phase of the Service Lifecycle is concerned with ensuring that services operate within agreed parameters. When service interruptions do occur, Service Operation is charged with restoring service as quickly as possible and with minimizing the impact to the business.

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Business Value

Service Operation is the only lifecycle phase in which value is actually realized by customers. Whereas all other phases of the Service Lifecycle contribute to and enable value, it is only experienced during Service Operation.

Service Operation also adds business value by:

 

  • Ensuring that services are operated within expected performance parameters
  • Restoring services quickly in the event of service interruption
  • Minimizing impact to the business in the event of service interruption
  • Providing a focal point for communication between users and the Service Provider organization

 

Concepts and Models

[bs_icon name=”glyphicon glyphicon-chevron-right”] Balance

Because Service Operation is the first lifecycle phase in which the Service Provider organization must respond to rather than plan for and drive user and customer demand, balance is difficult to maintain. Accordingly, ITIL® emphasizes the importance of striving to achieve and maintain balance during Service Operation in the form of specific balances between :

 

  • Reactive and Proactive Focus
  • Internal and External Focus
  • Cost and Quality
  • Stability and Flexibility

 

[bs_icon name=”glyphicon glyphicon-chevron-right”]  Communication

During Service Operation, the importance and criticality of communication is especially acute. ITIL stresses the importance of communication :

 

  • Between users and the IT Service Provider
  • Between customers and the IT Service Provider
  • Between different processes, functions, teams, etc. within the IT Service Provider
  • Between the IT Service Provider and its suppliers

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Incident

An incident is any occurrence which causes or may cause interruption or degradation to an IT Service.

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Problem

A problem is the unknown underlying cause of one or more incidents. A problem is NOT just a particularly serious incident.

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Error

An error is the known underlying cause of one or more incidents.

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Known Error

A known error is the known cause of an incident for which a workaround also exists.

 

[bs_icon name=”glyphicon glyphicon-chevron-right”] Event

An event is any change of state of an infrastructure or other item which has significance for the delivery of a service.

 

**Source by wikipedia**

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Posted by & filed under Exin ITIL.

 

Service Transition Processes

[bs_icon name=”glyphicon glyphicon-chevron-right”]  Change Management

 

Change Management is concerned with recording, evaluating, approving, testing, and reviewing changes to services, systems, and other Configuration Items. Read more »

Posted by & filed under CompTIA Network+, MICROSOFT MTA NETWORKING.

User authentication is the verification of an active human-to-machine transfer of credentials required for confirmation of a user’s authenticity; the term contrasts with machine authentication, which involves automated processes that do not require user input.

Source mc mcse Certification Resources

  • PKI (Public Key Infrastructure) – A public key infrastructure (PKI) is the combination of software, encryption technologies, processes, and services that enable an organization to secure its communications and business transactions.
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