Friday, July 6, 2018

Types of warehouse operation (Part 1)

There are many different roles for a warehouse in today’s supply chain. As can be seen in Figure 1.1, warehouses can be operated by raw materials suppliers, component and finished goods manufacturers, wholesalers, retailers and companies involved in reverse logistics. The warehouses can be owner operated or subcontracted to third-party logistics providers.
These warehouses fulfil the following roles:

Related image
Raw materials storage
These warehouses store raw materials and components either close to the point of extraction or close to the manufacturing point. Raw materials must be held in order to ensure continuous production. These materials include plastics, precious metals, sand, aggregates, etc.
Intermediate, postponement, customization or sub-assembly facilities
These warehouses are used to store products temporarily at different stages in production. These centres are also used to customize products before final delivery to the customer.

Postponement and sub-assembly activities can include the following:

  • specific packaging or labelling being changed or added, eg for storeready items or printing in different languages;
  • computer assembly to include different graphics cards, memory chips,
  • software, etc;
  • product bundling for promotional activity;
  • country-specific items being added such as electrical plugs; and
  • special messages being added, eg stencilling of greetings messages on mobile phones.

Finished goods storage
These warehouses store products ready for sale, on behalf of manufacturers, wholesalers and retailers. They provide a buffer or safety stock for companies, enabling them to build up stock in preparation for new product launches, expected increases in demand and to deal with seasonality.

Consolidation centres and transit warehouses
Consolidation centres receive products from different sources and amalgamate them for onward delivery to the customer or onto a production line. This can include just-in-time centres where automotive parts are delivered to a warehouse where they are brought together and sequenced for delivery onto the production line. They can also be retail stock consolidation warehouses where products from different suppliers are consolidated for onward delivery to the stores. Rather than deliver part-loads to the Retail Distribution Centres (RDC), manufacturers deliver to these facilities where their stock is consolidated with other suppliers for onward delivery to the RDC. These differ from cross-dock centres in that product can remain in the centre for a period of time awaiting call-off
from the final destination. Many of these consolidation centres are operated by third parties.

Transhipment or break-bulk centres
Transhipment centres receive products in large quantities from suppliers and break them down into manageable quantities for onward delivery to various locations.

Cross-dock centres
Cross-dock centres are seen as being the future for warehousing. Efficient consumer response and quick response within retail require operations to be able to move goods quickly through the supply chain. Cross docking requires deliveries into these centres to be already labelled and ready for onward delivery. Here the items are identified and consolidated with other deliveries, ready for despatch. Items should remain in the warehouse for as short a time as possible. Same-day receipt and despatch is the target. Although companies are beginning to realize the efficiency of cross docking, there are a number of barriers to a successful introduction. These can include warehouse management systems support, quality control systems, reliability and cooperation of suppliers and carriers, warehouse design and uncertain demand. Cross-dock warehouses or transhipment centres are also utilized in outlying geographic areas to transfer products onto local, radial distribution vehicles. This transhipment process can take place either inside or outside the warehouse. Typical cross-dock products are perishable items such as fruit and vegetables, meat and fish, which need to be moved quickly through the supply chain. Motorola’s recent study (2013) showed that 31 per cent of companies practised cross docking and this was expected to increase to 45 per cent by 2018.

Sortation centres
Sortation centres are used in the main by letter, parcel and pallet distribution companies. Goods are collected from all parts of the country, delivered into hubs or sortation centres, sorted by zip or post code, consolidated and delivered overnight to their respective distribution areas for onward delivery.
Today’s retailers are also moving towards automated sortation centres with pallets being de-layered on entry, the use of mini-load systems for temporary storage and retrieval and finally automated pallet build on exit.

Fulfilment centres
The growth of e-retailing has seen an increase in the number of customer fulfilment centres. These warehouses have been designed and equipped specifically. to manage large volumes of small orders. 
These centres can also double up as returns processing centres as e-commerce has a larger percentage of returns than normal retail activities. This area is covered in greater detail later in this chapter.

Reverse logistics centres
The growth of e-retailing and specific environmental legislation such as the European Union’s Waste Electrical and Electronic Equipment (WEEE) Directive (2007) has compelled companies to focus time and energy on reverse logistics.
Today, companies recognize that returning product to stock or disposing of it quickly can positively affect cash flow. As a result, a number of warehouses have been set up specifically to deal with returned items. Third-party contractors are providing a service to retailers where customers return unwanted or defective items to the stores; the items are then consolidated and sent to the returns centre, where they are checked and either repackaged, repaired, recycled or disposed of. Waste legislation has also resulted in large quantities of returned packaging having to be disposed of in an environmentally friendly manner. This includes sortation by type and use as fuel or recycled material. There are case studies in the environmental section that go into more detail on this subject.
Other reverse logistics processes include the return of reusable transit packaging equipment such as roll cages, barrels, kegs, pallets, tote boxes and trays. When used in the food industry added services include washing and sanitizing the items before they re-enter the supply chain. For example, Norbert Dentressangle, a 3PL, service and maintain more than a million roll cages, as well as 230 million trays and flower buckets and dollies for Tesco.

Public sector warehousing
Outside the commercial world there are also warehouse operations which support the public sector, armed forces and the third sector. The increasing number of natural disasters such as earthquakes, droughts and tsunamis is resulting in third-sector organizations opening up warehouses in strategic locations across the globe. This ensures that they are closer to the disaster areas and thus able to react quicker.

Other public sector warehouses will store supplies for local government facilities such as schools and offices. Products will include stationery, uniforms, furniture, computer hardware and software, etc.
All the warehouse operations mentioned above can be owned, leased or operated by third-party companies on behalf of a principal.
Warehouses operated by third-party logistics providers are either dedicated operations on behalf of a single customer or can be shared-user or public warehouses where a number of different customers share resources and are accommodated under one roof.
These include:
  • companies with different products but with common customers such as retailers or automotive manufacturers;
  • companies with the same or similar products delivering to common customers, eg tyre manufacturers; bicycle manufacturers, pharmaceutical companies and multimedia companies (a typical example is where Sony, Universal and Warner share a warehouse in the United Kingdom);
  • companies needing similar types of service, eg fulfilment or returns processing; and
  • companies requiring the same environmental conditions, eg hazardous goods, explosives or temperature controlled.
Users of shared-user warehouses are, in the main, companies looking for economies of scale through sharing facilities, equipment and labour costs.

Why do we hold stock?
A supply chain with the minimum amount of stock within its pipeline is utopia. Unfortunately this happens very rarely. Our society and our markets are not predictable and therefore we need to hold stock at various stages within the supply chain. Increased consumer demand for greater choice has resulted in a proliferation of product ranges and sizes leading to unprecedented demands on storage capacity.
Reasons for holding stock are as follows.

Uncertain and erratic demand patterns 
Suppliers of ice cream, suntan lotion, umbrellas and the like will potentially experience erratic demand patterns based on the changeability of the weather. Other unpredictable sales can revolve around the launch of a new product and the progress of a team in a major competition such as football’s World Cup or baseball’s World Series events.

Thursday, July 5, 2018

The role of the warehouse

Warehouses have, in the past, been constantly referred to as cost centres and rarely adding value. The movement of production to the Far East, the growth of e-commerce and increasing demands from consumers has seen a step change in warehouse operations. Warehouses are now seen as a vital link within today’s supply chains. In fact, as stated in a recent survey by Motorola (2013):
                fewer organizations continue to view warehouses and DCs simply as commoditized
                links between endpoints of the supply chain. Warehouses are no longer necessary
                evils that are fundamentally cost centers. The movement from linear to complex,
                multi-node supply chains recognizes this shift in perception, and is being driven
                by greater volatility, constrained capacity, evolving regulations, major shifts in
                customer demographics and buying patterns, and increasingly demanding customer
                and supplier requirements. Warehouses today can drive competitive differentiation
                and, by doing so, increase profitable growth.

Image result for The role of the warehouse
The pressure remains on managers to increase productivity and accuracy, reduce cost and inventory whilst improving customer service.As an introduction to the main aspects of the book we set the context by examining the role of the warehouse in today’s economy and its likely place within future supply chains. We will also look at the factors involved in choosing a suitable location for a warehouse and how many warehouses might be required. We have also taken three examples of specialist warehousing and expanded on these. We realize there are other areas such as hazardous goods storage and maintenance stores, but the need to cover all the fundamental areas precludes us from going into these areas in detail.

We believe, however, that the same underlying principles apply, albeit with greater emphasis on both legal and safety aspects. The role of a supply chain is to deliver the right products, in the correct quantity, to the right customer,at the right place, at the right time, in the right condition, at the right price. The warehouse plays a significant part in this. Delivering the right product in the right quantity relies on the warehouse picking and despatching products accurately. Delivering to the right customer at the right place, on time, requires the product to be labelled correctly and loaded onto the right vehicle with sufficient time to meet the delivery deadline. The warehouse also has to ensure the product leaves the warehouse clean and damage free. Finally, at the right price requires a cost efficient operation that delivers value for money.The warehouse is therefore crucial in delivering the perfect order. This can be done in many ways.

In the past, warehouses were seen mainly as stockholding points, attempting to match supply to demand and acting as a buffer between raw material and component suppliers and the manufacturers and between the manufacturers and the wholesalers and retailers and/or consumers. Stock visibility along the supply chain was limited and information flow was very slow, resulting in companies holding more stock than necessary.
Warehouses also fulfilled a major role in storing raw materials. As land and buildings were relatively cheap, the cost of holding significant quantities of raw materials and finished stock was seen as the norm and totally acceptable. Production runs in those days were very long as it was an expensive process to change models, colours, styles, etc. The economy was also seen as supply driven with manufacturers producing products in the hope that retailers would stock them and consumers would buy them. As a result there was a large proliferation of warehouses and stockholding increased appreciably.
In today’s market with expensive land, buildings, labour and energy costs, together with the introduction of concepts such as just in time (JIT), efficient consumer response (ECR) and quick response (QR), companies are continually looking to minimize the amount of stock held and speed up throughput. The use of tools such as postponement – where products are completed in the warehouse, not at the manufacturing location – are becoming common place. We have gone from a ‘push’ to a ‘pull’ supply chain over recent years. In fact, the phrase ‘supply chain’ can be a bit of a misnomer and rather it should be called a demand chain, with consumers holding sway.
In the past, manufacturers produced goods and passed them on to the retailers, expecting them to sell as many of their products as possible. The manufacturers operated a large number of local warehouses and delivered product direct to store. This situation changed in the 1980s when retailers took partial control of their supply chains and began to build national and regional distribution centres. This  changed the face of warehousing with a move towards larger, multi-temperature sites owned by the retailers and in many situations operated by third-party logistics companies.
These sites continue to grow, with Tesco recently building a 1.2 million square foot warehouse at Teesport in the United Kingdom, and Marks & Spencer have commissioned a 900,000 square foot distribution centre at London Gateway, the UK’s new super port. The location of these warehouses are also part of a movement towards port-centric logistics. The trend towards outsourcing Western production to India and Asia has resulted in companies having to hold higher levels of finished goods stock than previously. This is to cover the extended lead time between production and final delivery.
Containers from Shanghai to the United Kingdom, for example, can take upwards of 31 days, not including clearance at the port of entry. As can be seen in Figure 1.1, there is a requirement for some form of warehouse operation throughout the supply chain.

Giải pháp hội nghị truyền hình 2 site | GIẢI PHÁP 02 TRUYỀN HÌNH 2 ĐIỂM VÓI POLYCOM

1. Giới thiệu chung :
Hệ thống Video Conferencing ngày nay là một dịch vụ mở rộng trên nền hạ tầng IP. Mục tiêu của
việc triển khai hệ thống này là nhằm triển khai dịch vụ thông dụng và phổ biến hiện nay cho phép các
công ty ở trụ sở chính và các công ty thành viên tại chỗ hoặc ở xa có thể trao đổi với nhau không chỉ
bằng lời nói và mà bằng hình ảnh và không chỉ với một vài công ty mà có thể tham gia nhiều công ty
cùng lúc, từ đó hình thành một mạng thống nhất trên toàn hệ thống mạng.
Nắm bắt được các lợi ích mạnh mẽ của công nghệ video conferecing của Polycom cũng như
xuất phát từ nhu cầu thực tiễn của khách hàng, kế hoạch xây dựng hệ thông video conferencing kết nối Hà Nội và Hồ Chí Minh nhằm thực hiện mục tiêu hội nghị thông qua môi trường video conferencing để phục vụ công tác hội họp, quản lý, điều hành, khai thác thông qua môi trường mạng một các hiệu quả và tiết kiệm chi phí. Là một nhà cung cấp giải pháp video conferencing hàng đầu trên thế giới Polycom cung cấp các giải pháp cho phép tất cả các đối tượng khách hàng luôn thành công trong việc kết nối và hội nghị, không phụ thuộc vào môi trường và vị trí địa lý. Giải pháp Polycom cho phép cộng tác một cách hợp nhất, cùng với sự hỗ trợ của hạ tầng và các công cụ quản lý. Được tích hợp trong các giải pháp của Polycom luôn đảm bảo cho các người dùng truyền nhận đơn giản, bền vững mọi lúc mọi nơi trong môi trường cộng tác hợp nhất. Tất cả các giải pháp của Polycom được xếp hạng thế giới và các tổ chức hỗ trợ, sản phẩm được phân phối trên 40 văn phòng đại diện ở 20 quốc gia trên toàn cầu.
2. Thông tin yêu cầu :

- Hệ thống hội nghị truyền hình (Video Conference) cho 2 site.
- Sử dụng hệ thống Video Conference cho hội sở với chi nhánh.
- Sử dụng Video Conference point to point giữa 2 điểm bất kỳ nào đó
- Sử dụng Video Conference giữa Trung tâm với 2 điểm đồng thời
3. Giải pháp đề xuất :
Thiết bị đầu cuối Hội Nghị Truyền Hình tại 2 điểm cho các vị trí sẽ sử dụng thiết bị Polycom-HDX
8000.Chức năng cho hội nghị 2 điểm có thể sử dụng thiết bị hội nghị truyền hình Polycom-HDX 8000 giai đoạn này sẽ đầu tư 2 thiết bị quản lí 2 điểm đồng thời với tốc độ cho phép là 384Kbps cho mỗi site tham gia vào cuộc gọi.

Mô hình đề xuất hội nghị truyền hình 2 điểm

Thiết bị hội nghị truyền hình Polycom-HDX 8000 này đặt tại Trung tâm hội sở và chi nhánh nơi
có dung lượng đường truyền lớn dễ dàng nâng cấp đáp ứng nhu cầu sử dụng, giai đoạn này thiết bị
được đầu tư có thể kết nối đồng thời 2 vị trí thông qua giao thức IP.
Về tốc độ đường truyền nếu tất cả các điểm kết nối có tốc độ trên thiết bị là 384Kbps, thì tuỳ theo
số lượng điểm kết nối về đồng thời ta sẽ tính được tốc độc trung bình như bảng bên dưới, tuy nhiên theo phép tính toán an toàn nhất của thiết bị Polycom thì phải thêm 20% của băng thông được ấn định trên thiết bị đầu cuối là: 384Kbps + (20%*384)= 460Kbps (tương đương băng thông 512Kbps nếu thuê từ nhà cung cấp dịch vụ) tại mỗi điểm khi kết nối.
Ngoài ra để đạt được chất lượng hình ảnh HD thì băg thông tối thiểu phải 1024Kbps cho mỗi
điểm tham gia vào hội nghị truyền hình.

Băng thông yêu cầu tối thiểu cho viêc kết nối hội nghị truyền hình 2 điểm

Tại site 1 và site 2 sử dụng hội nghị truyền hình giữa 2 điểm thì có thể gọi trực tiếp giữa 2 điểm
với nhau thông qua địa chỉ IP đã được gán trên thiết bị hoặc thông qua tên hay số do quản lí theo quy
Yêu cầu đường truyền đủ lớn cho 02 vị trí cùng hội nghị với nhau, nhằm đảm bảo chất lượng
hình ảnh và âm thanh phục vụ tốt cho hội nghị.

Tương thích các chuẩn truyền thông H.323 theo khuyến nghị của ITU-T.
- Tương thích với các mạng, thiết bị của các nhà sản xuất khác trên chuẩn chung.
- Cấu trúc không làm gây ra trễ, nghẽn trong quá trình hội nghị.
- Có khả năng chuyển mã bất cứ yếu tố nào liên quan đến kết nối hội nghị: giao diện mạng,
băng thông, mã hóa….
- Có khả năng định tuyến cuộc gọi.
- Có khả năng cung cấp báo cáo hoạt động của hệ thống
- Được quản lý tại chỗ và từ xa qua trên nền ứng dụng Windows, Web… giao diện người dùng
thân thiện,…
- Tính năng khắc phục lỗi cho hình ảnh.

Với mô hình kết nối như trên ta sẽ có các loại hình ảnh hiển thị trên màn hình khi hội nghị truyền
hình diễn ra.

4. Thông tin về các nơi lắp đặt thiết bị đấu cuối Polycom
Thiết bị bao gồm:
- Thiết bị xử lí hội nghị truyền hình của Polycom HDX8000 giao tiếp với mạng LAN, video, audio.
- Camera ghi hình trong phòng hội nghị (có thể kết nối đến 2 chiếc nếu phòng lớn và người tham
gia hội nghị ngồi không tập trung).
- Microphone mở rộng 1 cái (có thể kết nối đến 2 cái).
- Tính năng People+Content sử dụng cáp kết nối trực tiếp vào bất cứ máy tính nào trình (hoặc
phần mềm cài đặt trên từng máy tính) cho phép trình diễn (presentation) nội dung trên máy tính cá nhân chia sẽ cho các vị trí tham gia hội nghị cùng xem, thông tin này sẽ hiển thị đồng thời trên
màn hình hội nghị truyền hình.
- Các phụ kiện gồm cáp kết nối với thiết bị như: màn hình, loa, micro, camera,..

Yêu cầu vị trí đặt thiết bị hội nghị phải có:
- Vị trí đặt thiết bị trên kệ đặt điểm giữa và đầu bàn họp, độ cao sao cho camera thấy được hình
toàn bộ người tham dự
- Nguồn điện 110-220 VAC.
- Địa chỉ IP tĩnh trong mạng LAN cho thiết bị hội nghị, IP này không bị hệ thống Firewall ngăn
- Mạng LAN liên kết được với các điểm hội nghị khác thông qua WAN hay Internet.
o Nếu sử dụng thông qua Internet (ADSL hoặc Leased Line) thì cần địa chỉ IP
public ánh xạ trực tiếp tới IP address trong LAN trên thiết bị Polycom.
o Nếu sử dụng thông qua Leased Line hay VPN-MPLS thì IP address trong LAN
phải nằm trong vùng DMZ hoặc không bị firewall chặn port từ 1024-65535.
- Yêu cầu phải có màn hình hiển thị (máy chiếu hay tivi) có giao tiếp ngõ vào hình ảnh là S-Video
hoặc VGA.
- Ánh sáng trong phòng nếu tối quá sẽ không thấy rõ được mặt người tham dự.
- Hệ thống loa có tính năng khuếch đại âm thanh của Polycom với công suất 270W.

5. Thiết kế phòng lắp đặt
Phương án 1
- Thiết kế dạng phòng tròn
- Bao gồm một bàn tròn ở giữa và gồm 2 hàng ghế xung quanh đảm bảo cho việc hội họp của 60
- Mô phỏng dạng room theo phương án 1 như hình vẽ dưới đây.

Phương án 2
- Room có dạng như lớp học
- Các hàng ghế được xếp theo hàng
- Màn hình đặt phía trên vị chủ tọa
- Mô hình mô phỏng theo hình vẽ sau

Wednesday, June 27, 2018

What are Cryptomining & Cryptojacking | How do you defend against cryptojacking?

Transactions for various forms of cryptocurrency are verified and added to the blockchain digital ledger
Requires large amount of processing power and energy to be efficient
Unauthorized use of someone else’s computer to mine cryptocurrency

Symptoms and rectification of Cryptojacking
How is it done?

  • Hackers install malware or a script that does cryptomining into the compromised server/computer
  • The  malware or script (usually javascript) automatically starts up in the background and mines cryptocurrency for the hacker
  • This is most commonly done when a user visits an infected website or through phishing

  • High CPU and/or GPU usage
  • Overheating
  • Crashes or restarts
  • Slow response times
  • Unusual network activity (e.g. connections to mining-related websites or IP addresses). For example, you may notice unexpected PowerShell processes connecting to IP addresses associated with xmrpool[.]net, nanopool[.]org, moneropool[.]com, and similar addresses.

  • Investigate any abnormal activity
  • Disable Javascript on specific sites
  • Install anti-malware software and run periodic scans
  • Monitor logs for unusual activity

How do you defend against cryptojacking?
The following cybersecurity best practices can help you protect your internet connected systems and devices against cryptojacking: (source from
Use and maintain antivirus software.
Antivirus software recognizes and protects a computer against malware, allowing the owner or operator to detect and remove a potentially unwanted program before it can do any damage. (See Understanding Anti-Virus Software.)

Keep software and operating systems up-to-date.
Install software updates so that attackers cannot take advantage of known problems or vulnerabilities. (See Understanding Patches.)

Use strong passwords.
Select passwords that will be difficult for attackers to guess, and use different passwords for different programs and devices. It is best to use long, strong passphrases or passwords that consist of at least 16 characters. (See Choosing and Protecting Passwords.)

Change default usernames and passwords.
Default usernames and passwords are readily available to malicious actors. Change default passwords, as soon as possible, to a sufficiently strong and unique password.

Check system privilege policies.
Review user accounts and verify that users with administrative rights have a need for those privileges. Restrict general user accounts from performing administrative functions.

Apply application whitelisting.
Consider using application whitelists to prevent unknown executables from launching autonomously.

Be wary of downloading files from websites.
Avoid downloading files from untrusted websites. Look for an authentic website certificate when downloading files from a secure site. (See Understanding Web Site Certificates.)

Recognize normal CPU activity and monitor for abnormal activity.
Network administrators should continuously monitor systems and educate their employees to recognize any above-normal sustained CPU activity on computer workstations, mobile devices, and network servers. Any noticeable degradation in processing speed requires investigation.

Disable unnecessary services.
Review all running services and disable those that are unnecessary for operations. Disabling or blocking some services may create problems by obstructing access to files, data, or devices.

Uninstall unused software.

Review installed software applications and remove those not needed for operations. Many retail computer systems with pre-loaded operating systems come with toolbars, games, and adware installed, all of which can use excessive disk space and memory. These unnecessary applications can provide avenues for attackers to exploit a system.

Validate input.
Perform input validation on internet-facing web server and web applications to mitigate injection attacks. On web browsers, disable JavaScript execution. For Microsoft Internet Explorer, enable the cross-site scripting filter.

Install a firewall.
Firewalls may be able to prevent some types of attack vectors by blocking malicious traffic before it can enter a computer system, and by restricting unnecessary outbound communications. Some device operating systems include a firewall. Enable and properly configure the firewall as specified in the device or system owner’s manual. (See Understanding Firewalls.)

Create and monitor blacklists.
Monitor industry reports of websites that are hosting, distributing, and being used for, malware command and control. Block the internet protocol addresses of known malicious sites to prevent devices from being able to access them.

Monday, June 25, 2018

How to fix office activation licence issue / How to fix Office 365 /2016 “Activation” or “Unlicensed Product” Problems

In this article We will show you how to troubleshoot office activation licence issue(Office 365 /2016 “Activation” or “Unlicensed Product” Problems). These step practically followed by us and 100% working. Please follow several method step by step which help to resolve your query.

Step 1: Go to Control panel > Click on Credential Manager > Remove all office 365 email credential from window credentials.
Or you can open Run command and type --> control userpasswords2 --> Hit OK

Step 2: Delete all credential relate to office 365

Let's check status, and it's OK now.

Another WAY: 

Step: Open cmd(Command promopt) with administrator previlage > type cd c:\Program files\Microsoft office\office16 > then type cscript ospp.vbs /dstatus > after that you will see multiple key (as mentioned in screenshoot 3RQ6B & GMR2K) > Type cscript ospp.vbs /unpkey: 3RQ6B & cscript ospp.vbs /unpkey: GMR2K  (to remove license from office) and after that you can reactivate office licence.

Note:- If still you face office activation licence issue then follow last method and we are dam sure that last method will resolve your issue 100%.


Step: Open Run(Press Window+R botton) > Type regedit and press Enter > Go to location (Computer\HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Office\16.0\Common) > Then right link on OEM and delete that > After that please close these. Then open office type user name password of your email account, you will see that your office licence activate.

Related Posts :

How to removing saved credentials from Windows XP, Windows Vista, Windows 7, or Windows 10

Top 10 Key Most Commom Interview Questions for Network Administrators

Getting ready for your first network admin interview? Here are technical questions to expect, along with the answers.
If you're not properly prepared, technical interviews can turn sour in a hurry. IT managers are looking for a good fit from a cultural perspective, but they also want to make sure you can handle tasks that require thorough understanding of specific IT functions. This is especially true for eager candidates who want to break into IT infrastructure roles such as network administrator.
In most organizations, the role of the network admin covers three primary areas: routing and switching, wireless LAN technologies, and security. The day-to-day care and feeding of a network often involves understanding the Spanning Tree Protocol, routing protocols, and network monitoring/troubleshooting tools. Competency in physical cabling is also useful as network administrators are often tasked with adding/moving various network components around, which requires them to connect/disconnect devices using copper Ethernet, fiber optics, DAC and various other LAN and data center physical connectivity options.
Wireless LAN technologies are an increasingly important skillset for network administrators. This includes knowing how to setup and secure WiFi SSIDs, but also how WiFi signals are propagated. Knowing wireless fundamentals such as frequency, wavelength, refraction, diffraction, and signal-to-noise ratio (SNR) helps for troubleshooting common issues such as interference, physical obstructions and noise.
Finally, network administrators are required to have a solid background in IT security, at least from a network perspective. This includes understanding firewalls, intrusion-prevention systems, secure remote access, data loss prevention, and end-to-end data encryption. Even in large companies that have their own IT security department, it’s common for the network administrators to do much of the heavy lifting when it comes to designing, integrating, and managing network security devices.
If you’re getting ready for your first network administrator interview, here are 10 technical questions employers are likely to ask.

1. What is the smallest IPv4 subnet mask that can be applied to a network containing up to 30 devices?
One of the first lessons a network administrator must learn is how to properly size IPv4 subnets. Whether you have a standard /24 VLAN for end users, a /30 for point-to-point links, or something in between, understanding how to subnet is a vital skill. To answer this question, a subnet that must contain up to 30 devices works out to be a /27 – or a subnet mask of Be sure you can perform this work with a pen and a sheet of paper. To check your work, feel free to use subnet calculator sites such as this one.

2. What's the purpose of Spanning Tree?
One of the most confusing topics for new network administrators is the Spanning Tree Protocol (STP). This protocol operates at layer 2 of the OSI model with the purpose of preventing loops on the network. Without STP, a redundant switch deployment would create broadcast storms that cripple even the most robust networks. There are several iterations based on the original IEEE 802.1Dstandard; each operates slightly different than the others while largely accomplishing the same loop-free goal. This is partly why STP is so confusing. Topics such as path cost calculations, root bridge IDs, BPDUs, and root/BPDU guard should be well understood prior to any technical interview.

3. What does "stateful" mean at it relates to stateful firewalls?
Firewalls have become a crucial network admin competency in any enterprise organization. The basic premise behind modern firewalls is that access policies are configured to only allow traffic to and from specific IP addresses and TCP/UDP ports. To help accomplish this goal, the firewall maintains a dynamic “state table.” Within this state table, you’ll find information regarding the active connections that pass between secure interfaces. Only packets that match the rules and are known to the firewall as “active” will be permitted to pass through. This eliminates the possibility that a rogue – and potentially malicious – packet would be accidently masked as legitimate and allowed into secure portions of the LAN.

4. Which travels farther, 2.4 GHz or 5 GHz WiFi signals and why?
The 2.4 and 5 GHz spectrums are both used in enterprise WiFi deployments. While the 5 GHz range boasts better transmit and receive speeds, it does so at the cost of signal propagation. Because the 2.4 GHz radio waves are in a lower frequency spectrum, the waves are larger and thus can travel farther – and are more capable of penetrating obstructions.
5. Can you explain what the purpose of administrative distance (AD) is as it relates to routing protocols?
When using a dynamic routing protocol in conjunction with static routes or other dynamic routing protocols, administrative distance (AD) becomes a key consideration. Within a router, there may be many routes to the same destination. For example, you may have a route to the network learned by both EIGRP and OSPF. So, which will the router choose to place into the routing table? The one with the lowest AD, of course. By default, EIGRP-internally learned routes have an AD of 90 while OSPF has an AD of 110. Thus, the route placed into the routing table would be the EIGRP learned route.
6. Provide examples of when you would use a static NAT, and when you might use a dynamic NAT
Network address translation (NAT) is often used at the internet edge. Internet-connected businesses own or lease publicly routable IPv4 space. Then within the local LAN, they use non-routable, RFC 1918 IP subnets. For those devices to reach the internet, NAT is used to convert the non-routable IP address to one that is routable. NAT maintains a table that maps the internal IP to the external IP. This mapping can either be static or dynamic in nature. For servers that must always be accessible by other devices on the Internet, a static NAT is the proper choice. That way, the server is always reachable using the same public IP address. For users who only need access out to the internet, dynamic NAT is the preferred choice; it allows hundreds or thousands of devices to share a single publicly routable address. The NAT table keeps track of the different dynamic mappings using a 16-bit port number. This is technically known as port address translation (PAT).
7. What is the purpose of the ARP table?
Network pros must understand how layer 2 switching and layer 3 routing work together on a network. This is where the ARP table comes into play. On layer 3 network devices such as routers or layer 3 switches, the ARP table maintains a list of known IP addresses and their corresponding MAC address where their next layer 2 hop resides. Static ARP entries can be configured. However, in most cases, the ARP table is dynamically learned using broadcast messages originating from the end device that are learned by the subnet’s L3 gateway.
8. Why does voice and video traffic use the UDP protocol as opposed to TCP?
Real-time streaming of data such as voice and video is becoming increasingly important. Because this type of data is time sensitive, it doesn’t make sense to use the TCP protocol that has built-in retransmission capabilities in the event the original packet doesn’t reach its destination. Instead, UDP is used because it does not have retransmission features. Instead, UDP’s “best effort” transport service is far better suited in situations where a packet or two lost does not mean the entire data set must be retransmitted.
9. What are two primary methods for authenticating WiFi users on an enterprise LAN?
The most basic authentication method is to use a WPA2 pre-shared key (PSK). The problem with the PSK is that it must be shared with all that use it. Thus, unless you change the key often, the network can become insecure. WPA2 PSK is sometimes used on enterprise LANs for guest users to allow them to access the internet and not any internal resources. For employees, the far more common authentication method is to use what’s known as WPA2 Enterprise, which allows users to login with 802.1x authentication. Typically, this is a RADIUS server that ties into a back-end Windows AD server. This method allows the user to seamlessly login to the enterprise LAN using their own password that’s tied to their AD account.
10. Can you identify SC, ST and LC fiber connectors?
Finally, it’s important to have a foundation in physical cabling options, both copper and fiber. Years ago, I was in a technical interview where the interviewer brought in a patch cable. The interviewer asked me whether the patch cable was single- or multi-mode and what the connection type was called. Fortunately, I knew that most single-mode fiber was yellow and that it had the smaller LC type connectors. If the patch cable is orange with round connectors that twist-lock, it’s almost certainly a multi-mode patch cable with ST connectors. Make sure you can quickly identify the most physical cabling types used in LANs and within data centers.

Thank you.


How to Fix 100% Disk Usage on Windows Task Manger

Recently, more and more Windows 10 users report that they have come across 100 disk usage Windows 10 issue.

In this article we will share hanging issue which is very common issue for us and we all are aware how to fix hanging issue when memory and CPU taking 100% utilization of system, but when you see harddisk 100% utilization on your system so you think to upgrade harddisk into SSD, before going to upgrade into SSD, please follow below step to fix issue. 

To fix the 100% disk usage issue please following the step.

Wednesday, June 13, 2018

How to connect MSSQL DATABASE in PHP (Using with codeigniter)

To connect MYSQL or MYSQLI in php is rather common than connetion SQL SERVER.  In my posted, i will using codeigniter for a example. For SQL SERVER in codeigniter, you need need to download some Drivers so that we can use SQL SERVER with other PHP .

The download version must be compatible to your PHP version example
Supported Operating System

  1. Version 4.0 supports PHP 7.0+ on Windows and Linux
  2. Version 3.2 supports PHP 5.6, 5.5, and 5.4 on Windows
  3. Version 3.1 supports PHP 5.5 and 5.4 on Windows
  4. Version 3.0 supports PHP 5.4 on Windows

link :

Step 1. 

Download the Drivers from the below link
Extracted sqlsrv drivers and copy to folder ext in your php version


Add these two line in your php.ini file

RESTART Apache (Wamp)
The Above step will install the required drivers for the php to support SQL SERVER . Only the connection with php application is left. For that we need to change the configuration. In Codeigniter you need to edit the file config/database.php file with the correct credentials and fields like database, port username ,password...

$db['default']['hostname'] = 'IP Sql server';
$db['default']['username'] = 'sa';
$db['default']['password'] = 'mssql';
$db['default']['database'] = 'YourDB';
$db['default']['dbdriver'] = 'sqlsrv';
$db['default']['dbprefix'] = '';
$db['default']['pconnect'] = FALSE;
$db['default']['db_debug'] = FALSE;
$db['default']['cache_on'] = FALSE;
$db['default']['cachedir'] = '';
$db['default']['options'] = array(PDO::ATTR_TIMEOUT => 5);
$db['default']['char_set'] = 'utf8';
$db['default']['dbcollat'] = 'utf8_general_ci';
$db['default']['swap_pre'] = '';
$db['default']['autoinit'] = TRUE;
$db['default']['stricton'] = FALSE;

After you changes in database.php, run you PHP apllication in the browser.


View on Youtube