Learn Ccna and Microsoft Server 2012

07/01/2021

'Network Security"
Topic: VAPT Introduction

Vulnerability Assessment and Pe*******on Testing (VAPT) describes a broad range
of security testing services designed to identify and help address cyber security
exposures.

In order to ensure that you choose the right type of assessment for your organisation’s
needs, it’s important to understand VAPT services and the differences between them.
The diverse nature of VAPT assessments means that they can vary significantly in
depth, breadth, scope and price.

What is VAPT?

VAPT is a term used to describe security testing that is designed to identify and help
address cyber security vulnerabilities. VAPT could include anything from automated
vulnerability assessments to human-led pe*******on testing and red team operations.

Why do you need VAPT?
The evolving tools, tactics and procedures used by cybercriminals to breach networks
means that it’s important to regularly test your organisation’s cyber security.
VAPT helps to protect your organisation by providing visibility of security weaknesses
and guidance to address them. VAPT is increasingly important for organisations wanting to achieve compliance with standards including the GDPR , ISO 27001 and PCI DSS .

VAPT Services
The broad definition of VAPT means the various services it describes are often
confused and used interchangeably. Before commissioning any form of VAPT security
testing, organisations should be aware of the services an assessment could include:

"Vulnerability Assessment "
A vulnerability assessment , often encompassing vulnerability scanning, is designed to help identify, classify and address security risks. Vulnerability assessment services also provide the ongoing support and advice needed to best mitigate any risks identified.

"Pe*******on Testing"
Pe*******on testing, or pen testing for short, is a multi-layered security assessment that
uses a combination of machine and human-led techniques to identify and exploit
vulnerabilities in infrastructure, systems and applications.

A pen test conducted by a professional ethical hacker will include a post-assessment
report detailing any vulnerabilities discovered and remediation guidance to help address
them.

Types of pe*******on testing:
● Internal/external infrastructure testing
● Web application testing
● Wireless network testing
● Mobile application testing
● Build and configuration review testing
● Social engineering testing

06/01/2021

SD-WAN: Is It Right for Your Network?

Summary: Software-Defined Wide-Area Networking (SD-WAN) can offer a number of advantages over traditional networking techniques for enterprises moving to virtualized IT environments.

Current Analysis research has identified some key determinants that early adopters of SD-WANs have used to
justify – or not justify – the use of SD-WAN within their network:
1) Are your IaaS/SaaS/PaaS solutions performing according to spec? If so, then there’s not necessarily aneed to deploy new networking technology such as a software-defined WAN. If not, then a new
solution might give better cloud app performance and flexibility.

2) Do considerable changes in the network need to be made on a continuous or ongoing basis? Thesechanges may include technical changes as well as commercial ones. This point also relates to theoverall evolution of IT towards pay-as-you-go. If the pay-as-you-go model is attractive in theorganization, then SD-WAN solutions will help to achieve this compared to more static and traditionalIP/MPLS VPNs.

3) Do we have mission-critical applications that are bandwidth-hungry or particularly jitter-sensitiveand which need to be secure and free of congestion or quality of service issues? Organizations thathave adopted SD-WAN have reported an enhanced ability to segment off portions of the network toaddress quality of service issues resulting from congestion on ‘peaky’ traffic from apps using voice orvideo.

4) Do we have a large number of remote sites with multiple WAN links, or are we planning to? Forlarger networks with multiple sites and WAN links, SD-WAN functional and economic advantages canbe compelling. However, with a smaller number of sites or if a majority of sites are singly connected,the advantages are harder to identify.

Architecture Choices: Three Options
If SD-WAN seems to answer one or more of these key questions, then it’s worth taking a closer look at the options to deploy SD-WAN in your network.

Three approaches can be considered, making more or less use of existing routing equipment and virtual CPE (vCPE) or universal CPE (uCPE):

 Deploy an overlay SD-WAN solution leveraging the existing IP router footprint
o If the enterprise has a major existing IP router estate then it may wish to preserve the existing
equipment and leverage an overlay solution for implementing SD-WAN. The overlay solution
offers the ability to failover to the traditional WAN setup in case there are issues with the SD-WAN infrastructure.
o Overlay solutions may lack capabilities in aligning existing OSS/BSS platforms in place with theservice provider, meaning a loss of some flexibility for billing and flexible payment for utilitySD-WANs.
o This approach will also require efforts for the existing WAN – be that IP VPN or Ethernet VPN,as well as implementing policy routing and on-going service chaining.
o Some routers available in the market today can support per-flow path forwarding based on
link performance and application policy, and network and application monitoring.

 Deploy a mixture of existing IP routers and vCPE/uCPE
o The vCPE or ‘thin CPE’ involves the virtualization of CPE, and this runs in the cloud.
o uCPE – or ‘Universal CPE’ is a site-based Intel server module that can support physical
networking such as being a branch router for multiple WAN interfaces including 3g/LTE, and beremotely manageable for running for example VNFs and hosted business communications likemedia gateways for SIP interoperability, etc .
o Most enterprise customers will want to explore a blend of existing IP VPN architecture withsome aspects of the WAN, featuring core SD-WAN based on core SDN/NFV and vCPE/uCPE.
Such deployments might begin with the SD-WAN architecture initially focusing on automatingIT between HQ sites and the data centres where cloud apps are being served from.
o Some of the technical issues mentioned in the overlay architecture are likely to apply to this
mixed set-up scenario, such as lack of support for fully integrated orchestration of the OSS/BSSfunctions.

 Deploy full SD-WAN based entirely on a new appliance, x86 server, or gateway on site, or on
vCPE/uCPE
o Virtualized software runs on x86 as a VM or containerized solution.
o The SD-WAN benefits from central orchestration and policy-based routing control.
o Enterprises adopting the full SD-WAN approach may employ the full range of SD-WANfeatures, including intelligent path selection, policy management, full automation, integrationwith OSS/BSS, zero touch deployment and security functions like IPsec VPN and firewalling.

Enterprises also need to consider whether to use a virtual SD-WAN controller in the cloud, or premises-based SD-WAN controller software. This choice tends to be sector-specific. For example, banking and financial firms
today tend to prefer premises-based controllers since financial firms more often run private MPLSenvironments; whereas retail chains, which favor public Internet and broadband links, may opt for cloud-hosted SD-WAN controller solutions.

"Key Use Cases for SD-WAN: Technical, Functional, and Economic"

Technical-
Traditional WANs are not Architected Specifically for Running Cloud Apps – Most SD-WAN solutions in the market focus on solving business connectivity that demands among other things major use of services
from within the cloud. Traditional IP/MPLS VPNs have adapted and evolved to feature connectivity to cloud estates, including both private and public clouds but there remain certain limitations on performance (i.e.,
scaling bandwidth) and app priority parameters over public Internet. Hybrid WAN solutions do offer APM and WAN optimization features, but for more comprehensive applications control, it is important to be able to understand how apps are behaving in the network and to be in a position to tailor or tweak SD-WAN parameters to maintain the apps running in the cloud in an efficient working fashion. Enterprises are
right to expect a self-serve interface within an online portal that allows them to make changes – and behind the self-serve feature lies automation so that changes do not demand intensive manual actions.

Functional-
Adding or removing sites – There are too many manual procedures for implementing such changes at the branch. Often a large enterprise will need to scale or shrink operations and this requires new office locations and end-users to be integrated with the existing WAN. The new SD-WAN environment should support the addition of new sites rapidly over multiple access types, such as leased line, Internet access, MPLS, 3G/4G LTE, and broadband. Provisioned circuits and interconnections need to meet the corporate security policy and be documented as per governance rules. SD-WAN services demonstrated that moves,
adds, and changes can be performed more conveniently and with fewer complications that might arise from say re-writing CLI scripts from scratch for every site. Policy driven SD-WAN configurations combined with automated policy selection and configuration enable zero-touch provisioning for drop-shipped CPE
devices on existing IP routers or via universal CPE (uCPE).
SD-WAN techniques such as these reduce human errors that creep into networks configured with manual configuration steps.
Try before you buy and Rapid Provisioning – MPLS does not offer the flexibility or agility for quickly deploying changes and for example trying out features for a short duration before committing to buy.
SD-WAN solutions increasingly support more choice of virtual network functions (VNFs) and both solution architecture and VNFs running over the test network design give engineers far greater flexibility for testing the network and the performance of cloud apps on the network before scaling to a full deployment.

Economic-
Scaling MPLS Can Take Time and Drive Up Costs – how can a new network solution help bypass the current inflexible nature of MPLS circuits? The central orchestration software for an SD-WAN should provide the systems administrator or network engineer with an interface that supports quick changes to
circuit design and performance parameters.

23/04/2020

https://youtu.be/n2D1o-aM-2s

13/11/2018

https://www.excitingip.net/146/enterprise-inter-branch-connectivity-wide-area-network/

Credits: excitingip

Most of the companies have multiple branches and more often than not, they would want a good network connectivity (Wide Area Network) across these branches. So, let us look at some of the popular o…

27/05/2017

Applicable for job seekers ! And fresher's .

Nokia CEO ended his speech saying this “we didn’t do anything wrong, but somehow, we lost”.

During the press conference to announce NOKIA being acquired by Microsoft, Nokia CEO ended his speech saying this “we didn’t do anything wrong, but somehow, we lost”. Upon saying that, all his management team, himself included, teared sadly.

Nokia has been a respectable company. They didn’t do anything wrong in their business, however, the world changed too fast. Their opponents were too powerful.

They missed out on learning, they missed out on changing, and thus they lost the opportunity at hand to make it big. Not only did they miss the opportunity to earn big money, they lost their chance of survival.

The message of this story is, if you don’t change, you shall be removed from the competition.

It’s not wrong if you don’t want to learn new things. However, if your thoughts and mindset cannot catch up with time, you will be eliminated.

Conclusion:
1. The advantage you have yesterday, will be replaced by the trends of tomorrow. You don’t have to do anything wrong, as long as your competitors catch the wave and do it RIGHT, you can lose out and fail.

To change and improve yourself is giving yourself a second chance. To be forced by others to change, is like being discarded.
Those who refuse to learn & improve, will definitely one day become redundant & not relevant to the industry. They will learn the lesson in a hard & expensive way!

23/05/2017

Some improvement and cool technologies by Google.

https://www.wired.com/2017/05/slickest-things-google-debuted-today-big-event/

From a new chip processor to Google Assistant on iOS.

08/05/2017

https://drive.google.com/drive/mobile/folders/0ByWO0aO1eI_MN1BEd3VNRUZENkU?sort=13&direction=a

Important self study content.

27/03/2017

STP is protocol that builds a loop free topology in meshed structure .Have you know this emerged with VLAN PVSTP (Per VLAN Spanning Tree Protocol .

26/03/2017

Networking Interview Questions and Answers
What is a Link?
Answer: A link refers to the connectivity between two devices. It includes the type of cables and protocols used in order for one device to be able to communicate with the other.

Define Network?
Answer: A network is a set of devices connected by physical media links. A network is recursively is a connection of two or more nodes by a physical link or two or more networks connected by one or more nodes.

Describe Domain Name System.
Answer: There are two types of client/server programs.
First is used directly by the user, such as e-mail, second supports other application programs. The Domain Name System (DNS) is a supporting program that is used by other programs such as to find the IP address of an e-mail recipient.

Have you worked in heterogeneous environments and multiple server and client platforms?
Answer: The obvious answer to this question is yes or no, but you should elaborate if the answer is yes. Most networking environments use a combination of Windows and Linux servers and desktops. Usually, network engineers prefer Linux servers and work with Windows and Linux desktops. Occasionally, you might have some Mac desktops as well to work with.

What is a LAN?
Answer: LAN is short for Local Area Network. It refers to the connection between computers and other network devices that are located within a small physical location.

What is Multiple Access?
Answer: If the physical links are shared by more than two nodes, it is said to be Multiple Access.

Define Fully Qualified Domain Name and Partially Qualified Domain Name.
Answer: In hierarchical name space, names are defined in an inverted-tree structure with the root at the top. The tree can have only 128 levels: level 0 (root) to level 127.
Each node in the tree has a label, which is a string with a maximum of 63 characters.
The root label is a null string (empty string). In this tree, all the labels have different name, which guarantee the uniqueness of the domain names.
A full domain name is a sequence of labels separated by dots (.). The domain names are always read from the node up to the root.
Fully Qualified Domain Name
If a label is terminated by a null string or empty string, it is called a fully qualified domain name (FQDN).
Partially Qualified Domain Name
If a label is not terminated by a null string, it is called a partially qualified domain name (PQDN). A PQDN starts from a node, but it does not end with the root.

How do you work with a development team?
Answer: Interestingly, most infrastructure and development teams don’t get along well with each other. When development teams and infrastructure teams get together to design large systems, they usually disagree with each other. There can be a lot of tension between the two departments. When you answer this question, make sure you give an answer that attempts to help a development team and facilitates progress instead of stifles it. You want to help developers complete projects while securing the network in the best way possible.


What are the advantages of Distributed Processing?
Answer:

a. Security/Encapsulation
b. Distributed database
c. Faster Problem solving
d. Security through redundancy
e. Collaborative Processing

What is anonymous FTP?
Answer: Anonymous FTP is a way of granting user access to files in public servers. Users that are allowed access to data in these servers do not need to identify themselves, but instead log in as an anonymous guest.

What are the layers of the OSI reference model?
Answer: There are 7 OSI layers: Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer and Application Layer.

What is a node?
Answer: A network can consist of two or more computers directly connected by some physical medium such as coaxial cable or optical fiber. Such a physical medium is called as Links and the computer it connects is called as Nodes.

Describe Hierarchical Namespace.
Answer: In a hierarchical name space, each name is combination of several parts as:
Type of the organization.
Name of an organization.
Departments in the organization.
A central authority can assign the part of the name that defines the nature and name of the organization. The other things of the name the organization provides itself. The organization can add suffixes (or prefixes) to the name to define its host.
The company need not worry about the prefix if it is same as that of another organization because, even if part of an address is the same, the whole address is different.

What tools do you use to troubleshoot network issues?
Answer: You can use any tools to troubleshoot issues, but you should mention some internal typical commands that help troubleshoot standard problems. For instance, if the user can’t access the Internet, you might want to run a tracert on the problem. You could also use ping to see if the user can access internal areas of the network. Of course, there could also be hardware issues such as a bad network card or broken cable.

What is point-point link?
Answer: If the physical links are limited to a pair of nodes it is said to be point-point link.

What things should you consider when you work with several departments and large infrastructures?
Answer: One main issue with larger businesses is security. If the business hosts its own web host servers, you must understand how to protect the internal network from outside Internet traffic. Other issues include user management and desktop audits and inventory. You must be able to manage several desktops and servers at once.

What are the criteria necessary for an effective and efficient network?
Answer:
a: Performance
It can be measured in many ways, including transmit time and response time.
b: Reliability
It is measured by frequency of failure, the time it takes a link to recover from a failure, and the network's robustness.
c: Security
Security issues include protecting data from unauthorized access and viruses.

What is subnet mask?
Answer: A subnet mask is combined with an IP address in order to identify two parts: the extended network address and the host address. Like an IP address, a subnet mask is made up of 32 bits

What is a gateway or Router?
Answer: A node that is connected to two or more networks is commonly called as router or Gateway. It generally forwards message from one network to another.

What are some basic ways to speed up network performance?
Answer: There are several ways to improve network performance. You can first make sure you disable peer-to-peer downloading and torrents. Some companies restrict media streaming such as YouTube and Pandora. You can also add compression to files to reduce the amount of bandwidth used. Another area where some network admins make mistakes is timed backups and large data transfers. Make sure your backups are done during slow network times, which is usually overnight when the office is closed.

19/03/2017

"100% Job Guaranteed CCNA Interview Questions with Answers"

Q.1: What is Routing?

Ans: Routing is the process of finding a path on which data can pass from source to destination. Routing is done by a device called routers, which are network layer devices.

Q.2: What is the purpose of the Data Link?

Ans: The job of the Data Link layer is to check messages are sent to the right device. Another function of this layer is framing.

Q.3: What is the key advantage of using switches?

Ans: When a switch receives a signal, it creates a frame out of the bits that was extracted from that signal. With this process, it gains access and reads the destination address, after which it forwards that frame to the appropriate port. This is a very efficient means of data transmission, instead of broadcasting it on all ports.

Q.4: When does network congestion occur?

Ans: Network congestion occurs when too many users are trying to use the same bandwidth. This is especially true in big networks that do not resort to network segmentation.

Q.5: What is a Window in networking terms?

Ans: A Window refers to the number of segments that is allowed to be sent from source to destination before an acknowledgement is sent back.

Q.6: Does a bridge divide a network into smaller segments?

Ans: Not really. What a bridge actually does is to take the large network and filter it, without changing the size of the network.

Q.7: Which LAN switching method is used in CISCO Catalyst 5000?

Ans: This model uses the Store-and-forward switching method. It stores the entire frame to its buffers and performs a crc check before deciding whether or not to forward that data frame.

Q.8: What is the role of the LLC sublayer?

Ans: The LLC sublayer, short for Logical Link Control, can provide optional services to an application developer. One option is to provide flow control to the Network layer by using stop/start codes. The LLC can also provide error correction.

Q.9: How does RIP differ from IGRP?

Ans: RIP relies on the number of hops in order to determine the best route to a network. On the other hand, IGRP takes consideration many factors before it decides the best route to take, such as bandwidth, reliability, MTU and hop count.

Q.10: What are the different memories used in a CISCO router?

Ans: - NVRAM stores the startup configuration file

- DRAM stores the configuration file that is being executed

- Flash Memory – stores the Cisco IOS.

Q.11: What is BootP?

Ans: BootP is a protocol that is used to boot diskless workstations that are connected to the network. It is short for Boot Program. Diskless workstations also use BootP in order to determine its own IP address as well as the IP address of the server PC.

Q.12: What is the function of the Application Layer in networking?

Ans: Application Layer supports the communication components of an application and provides network services to application processes that span beyond the OSI reference model specifications. It also synchronizes applications on the server and client.

Q.13: Differentiate User Mode from Privileged Mode

Ans: User Mode is used for regular task when using a CISCO router, such as to view system information, connecting to remote devices, and checking the status of the router. On the other hand, privileged mode includes all options that are available for User Mode, plus more. You can use this mode in order to make configurations on the router, including making tests and debugging.

Q.14: What is 100BaseFX?

Ans: This is Ethernet that makes use of fiber optic cable as the main transmission medium. The 100 stands for 100Mbps, which is the data speed.

Q.15: Differentiate full-duplex from half-duplex.

Ans: In full-duplex, both the transmitting device and the receiving device can communicate simultaneously, that is, both can be transmitting and receiving at the same time. In the case of half-duplex, a device cannot receive while it is transmitting, and vice versa.

Q.16: What is MTU?

Ans: MTU stands for Maximum Transmission Unit. It refers to the maximum packet size that can be sent out onto the data line without the need to fragment it.

Q.17: How does cut-through LAN switching work?

Ans: In Cut-Through LAN switching, as soon as the router receives the data frame, it will immediately send it out again and forward it to the next network segment after reading the destination address.

Q.18: What is latency?

Ans: Latency is the amount of time delay that measures the point from which a network device receives a data frame to the time it sends it out again towards another network segment.

Q.19: Utilizing RIP, what is the limit when it comes to number of hops?

Ans: The maximum limit is 15 hop counts. Anything higher than 15 indicates that the network is considered unreachable.

Q.20: What is a Frame Relay?

Ans: Frame Relay is a WAN protocol that provides connection-oriented communication by creating and maintaining virtual circuits. It has a high performance rating and operates at the Data Link and Physical Layers.

Q.21: How do you configure a Cisco router to route IPX?

Ans: The initial thing to do is to enable IPX routing by using the “ipx routing” command. Each interface that is used in the IPX network is then configured with a network number and encapsulation method.

Q.22: What are the different IPX access lists?

Ans: There are two access lists: Standard and Extended. Standard Access List can only filter the source or destination IP address. An Extended Access List uses the source and destination IP addresses, port, socket and protocol when filtering a network.

Q.23: Explain the benefits of VLANs.

Ans: VLANs allow the creation of collision domains by groups other than just physical location. Using VLANs, it is possible to establish networks by different means, such as by function, type of hardware, protocol, among others. This is a big advantage when compared to conventional LANs wherein collision domains are always tied to physical location.

Q.24: What is subnetting?

Ans: Subnetting is the process of creating smaller networks from a big parent network. Being a part of a network, each subnet is assigned some additional parameters or identifier to indicate its subnet number.

25) What are the advantages of a layered model in the networking industry?

Ans: A layered network offers many advantages. It allows administrators to make changes in one layer without the need to make changes in the other layers. Specialization is encouraged, allowing the network industry to make progress faster. A layered model also lets administrators troubleshoot problems more efficiently.

Q.26: Why is UDP lease favored when compared to TCP?

Ans: It’s because UDP is unreliable and unsequenced. It is not capable of establishing virtual circuits and acknowledgements.

Q.27: What are some standards supported by the Presentation layer?

Ans: Presentation layer supports many standards, which ensures that data is presented correctly. These include PICT, TIFF and JPEG for graphics, MIDI, MPEG and QuickTime for Video/Audio.

Q.28: What’s the simplest way to remotely configure a router?

Ans: In cases when you need to configure a router remotely, the most convenient is to use the Cisco Auto Install Procedure. However, the router must be connected to the WAN or LAN through one of the interfaces.

Q.29: What does the show protocol display?

Ans:

- routed protocols that is configured on the router

- the address assigned on each interface

- the encapsulation method that was configured on each interface

Q.30: How do you depict an IP address?

Ans: It can be done in three possible ways:

- using Dotted-decimal. For example: 192.168.0.1

- using Binary. For example: 10000010.00111011.01110010.01110011

- using Hexadecimal. For example: 82 1E 10 A1

Q.31: How do you go to privileged mode? How do you switch back to user mode?

Ans: To access privileged mode, you enter the command “enable” on the prompt. In order to get back to user mode, enter the command “disable”

Q.32: What is HDLC?

Ans: HDLC is short for High Level Data Link Control protocol, and is a propriety protocol of CISCO. It is the default encapsulation operated within CISCO routers.

Q.33: How are internetworks created?

Ans: Internetworks are created when networks are connected using routers. Specifically, the network administrator assigns a logical address to every network that connects to the router.

Q.34: What is Bandwidth?

Ans: Bandwidth refers to the transmission capacity of a medium. It is a measure of how much volume a transmission channel can handle, and is measured in Kbps.

Q.35: How does Hold-downs work?

Ans: Hold-downs prevent regular update messages from reinstating a downed link by removing that link from update messages. It uses triggered updates to reset the hold-down timer.

Q.36: What are packets?

Ans: Packets are the results of data encapsulation. These are data that has been wrapped under the different protocols of the OSI layers. Packets are also referred to as datagrams.

Q.37: What are segments?

Ans: Segments are sections of a data stream that comes from the upper OSI layers and ready for transmission towards the network. Segments are the logic units at the Transport Layer.

Q.38: Give some benefits of LAN switching.

Ans:

- allows full duplex data transmission and reception

- media rate adaption

- easy and efficient migration

Q.39: What is Route Poisoning?

Ans: Route Poisoning is the process of inserting a table entry of 16 to a route, making it unreachable. This technique is used in order to prevent problems caused by inconsistent updates on a route.

Q.40: How do you find valid hosts in a subnet?

Ans: The best way to go about this is to use the equation 256 minus the subnet mask. The hosts that are considered valid are those that can be found between the subnets.

Q.41: What is DLCI?

Ans: DLCI, or Data Link Connection Identifiers, are normally assigned by a frame relay service provider in order to uniquely identify each virtual circuit that exists on the network.

Q.42: Brielfly explain the conversion steps in data encapsulation.

Ans: From a data transmitter’s point of reference, data from the end user is converted to segments. Segments are then passed on to the other layers and converted into packets or datagrams. These packets are then converted into frames before passing on to the network interface. Finally, frames are converted to bits prior to actual data transmission.

Q.43: What are the different types of passwords used in securing a CISCO router?

Ans: There are actually five types of passwords that can be used. These are enable secret, enable, virtual terminal, console, and auxiliary.

Q.44: Why is network segmentation a good idea when managing a large network?

Ans: For a network administration, segmenting a network would help ease network traffic and ensures that high bandwidth is made available at all times for all users. This translates to better performance especially for a growing network.

Q.45: What causes a triggered update to reset the router hold-down timer?

Ans: This may happen when the hold-down timer has already expired, or when the router received a processing task that incidentally was proportional to the number of links in the internetwork.