What does a hard drive do?
Storage is the hard drive’s responsibility. Everything you keep on your computer is on a hard drive. Read more »
What Is Memory, or RAM?
System memory, frequently called main memory or RAM (Random Access Memory), is a type of computer memory that can be accessed randomly. Read more »
- 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)
- 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
Result contains:
- Identified critical functions and required resources
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- Identify organization’s critical business functions
Review the BIA
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- BIA contains the prioritized list of critical business functions
- Should be reviewed for compatibility with the BC plan
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- Project Initiation and Management
- Develop and Document Project Scope and Plan
- Computer/Cyber Crime
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- CryptoLocker Ransomware – Spreads via email and propagates rapidly. Encrypts various file types and then a pop-up window appears to inform user about the actions performed on computer and, therefore demand a monetary payment for files to be decrypted.
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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.
- Oversight Committee Representation Read more »
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- Organizational or corporate governance has existed since time immemorial to ensure the efficient running via control structures.
- Wireless Communications
- WAP (Wireless Applications Protocol)
–Developed for wireless (PDA’s, mobile phones, pagers, etc. devices to communicate)
Tunneling is a method of transferring data from one network to another by encapsulating the packets in an additional header. The additional header provides routing information so that the encapsulating payload traverse the intermediate networks. Read more »
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.
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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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Open Systems Interconnect (OSI) Model Read more »
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 »
[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 »
[bs_icon name=”glyphicon glyphicon-chevron-right”] Incident Management
Incident Management is concerned with the rapid restoration of services and with minimization of impact to the business. Read more »
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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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 »
[bs_icon name=”glyphicon glyphicon-chevron-right”] Change Authority
In ITIL® the entity charged with approval of a Request for Change is called the Change Authority. Read more »
IT Security Management is the process concerned with the protection of IT assets (including services) from security threats. Read more »
[bs_icon name=”glyphicon glyphicon-chevron-right”] Normal Changes are changes which meet predefined criteria that qualify them for handling via the Normal Change Management process.
The ‘Four P’s of Service Design’ represent areas which should be taken into consideration when designing a service. Read more »
Capacity Management is concerned with ensuring that cost-effective capacity exists at all times which meets or exceeds the agreed needs of the business as established in Service Level Agreements. Read more »
ITIL also utilizes the RACI model as a generic tool for reviewing and assigning four key roles to any important task or activity. Read more »
The Service Desk provides a single point of contact between users and the IT organization.
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- DoS (Denial of Service) – A DoS attack is a common type of attack in which false requests to a server overload it to the point that it is unable to handle valid requests, cause it to reset, or shut it down completely. Read more »
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- Physical Security – physical security is just as it sounds, locks on the doors, cameras everywhere, and so forth. Read more »
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.
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- 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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- ACL (Access Control List) – An ACL is a table in an operating system or network device (such as a router) that denies or allows access to resources. Read more »
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- Cable Testers – Cable testers are electronic devices used to test a cable’s integrity by checking for opens and shorts which can cause connectivity problems.
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- Application Layer vs. Network Layer – An application layer firewall works at the application layer of a protocol stack. Read more »
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Crosstalk
Symptoms: Slow network performance and/or an excess of dropped or unintelligible packets. In telephony applications, users hear pieces of voice or conversations from a separate line. Read more »
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Gather Information on the Problem
In a contact center network, problems are typically discovered and reported by one of the following types of users: Read more »
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- Bandwidth – is the average number of bits that can be transmitted from the source to a destination over the network in one second.
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- Quality of Service – (QoS) is a set of parameters that controls the level of quality provided to different types of network traffic. Read more »
Inter VLAN Communication (Router on Stick)
Earlier we built and tested the following topology: Read more »
The Open Systems Interconnection model (OSI model) is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to their underlying internal structure and technology. Read more »
Multilayer Switch – A multilayer switch (MLS) is a computer networking device that switches on OSI layer 2 like an ordinary network switch and provides extra functions on higher OSI layers.
Hub – A physical layer network device used to connect multiple Ethernet devices together. Read more »
Vertical Cross Connect – is a location within a building where cables originate and / or are terminated, reconnected using jumpers or pass throughs or are connected to patch panels or other similar devices where the locations are from upper or lower floors in the building. Read more »
[bs_icon name=”glyphicon glyphicon-chevron-right”] Peer to Peer – A peer to peer network is one in which lacks a dedicated server and every computer acts as both a client and a server. Read more »
Ethernet – Ethernet is the most widely-installed local area network ( LAN) technology. Read more »
[bs_icon name=”glyphicon glyphicon-chevron-right”] Frame Relay – Frame relay is a secure, private network that utilizes a logical path or “virtual circuit” to allocate bandwidth for high performance transmissions. Read more »
568A and 568B – The number 568 refers to the order in which the individual wires inside a CAT 5 cable are terminated. Read more »
Cable Types : Read more »
Wireless networks allow computers to comunicate without the use of cables using IEEE 802.11 standards, also known as Wi-Fi. Read more »
[bs_icon name=”glyphicon glyphicon-chevron-right”] Introduction To Network
