ASP.net link for Beginners

Some links for Beginners (Web):

Basic HTML:

http://www.codeproj ect.com/KB/ HTML/htmlbeginne r.aspx

http://www.itechcol lege.com/ courses/HTML/



ASP:

http://www.codeproj ect.com/KB/ asp/aspbegin. aspx

http://www.itechcol lege.com/ courses/ASP/

http://www.codeproj ect.com/KB/ asp/uwe-guestboo k.aspx

http://www.codeproj ect.com/KB/ asp/CDIChatSubmi t.aspx



JavaScript:

http://www.itechcol lege.com/ courses/JavaScri pt/



ASP.Net:

http://www.itechcol lege.com/ courses/ASP- NET/

http://www.asp. net/ (Contains huge video tutorials)



CSS:

http://www.itechcol lege.com/ courses/CSS/

http://www.itechcol lege.com/ courses/AJAX/



State Management (ViewState & Session):

http://www.codeproj ect.com/KB/ aspnet/BegViewSt ate.aspx

http://www.codeproj ect.com/KB/ aspnet/Exploring Session.aspx





And More…….:

http://www.w3school s..com/

http://www.codeproj ect.com/

http://www.codeproj ect.com/KB/ aspnet/Beginners _Walk_Web. aspx

What is TDD?

The steps of test first design (TFD) are overviewed in the UML activity diagram of Figure 1. The first step is to quickly add a test, basically just enough code to fail. Next you run your tests, often the complete test suite although for sake of speed you may decide to run only a subset, to ensure that the new test does in fact fail. You then update your functional code to make it pass the new tests. The fourth step is to run your tests again. If they fail you need to update your functional code and retest. Once the tests pass the next step is to start over (you may first need to refactor any duplication out of your design as needed, turning TFD into TDD).

TDD = Refactoring + TFD.

TDD completely turns traditional development around. When you first go to implement a new feature, the first question that you ask is whether the existing design is the best design possible that enables you to implement that functionality. If so, you proceed via a TFD approach. If not, you refactor it locally to change the portion of the design affected by the new feature, enabling you to add that feature as easy as possible. As a result you will always be improving the quality of your design, thereby making it easier to work with in the future.


Instead of writing functional code first and then your testing code as an afterthought, if you write it at all, you instead write your test code before your functional code. Furthermore, you do so in very small steps – one test and a small bit of corresponding functional code at a time. A programmer taking a TDD approach refuses to write a new function until there is first a test that fails because that function isn’t present. In fact, they refuse to add even a single line of code until a test exists for it. Once the test is in place they then do the work required to ensure that the test suite now passes (your new code may break several existing tests as well as the new one). This sounds simple in principle, but when you are first learning to take a TDD approach it proves require great discipline because it is easy to “slip” and write functional code without first writing a new test. One of the advantages of pair programming is that your pair helps you to stay on track.

An underlying assumption of TDD is that you have a unit-testing framework available to you. Agile software developers often use the xUnit family of open source tools, such as JUnit or VBUnit, although commercial tools are also viable options. Without such tools TDD is virtually impossible. Figure 2 presents a UML state chart diagram for how people typically work with the xUnit tools. This diagram was suggested to me by Keith Ray.
Kent Beck, who popularized TDD in eXtreme Programming (XP) (Beck 2000), defines two simple rules for TDD (Beck 2003). First, you should write new business code only when an automated test has failed. Second, you should eliminate any duplication that you find. Beck explains how these two simple rules generate complex individual and group behavior:

*

You design organically, with the running code providing feedback between decisions.
*

You write your own tests because you can't wait 20 times per day for someone else to write them for you.
*

Your development environment must provide rapid response to small changes (e.g you need a fast compiler and regression test suite).
*

Your designs must consist of highly cohesive, loosely coupled components (e.g. your design is highly normalized) to make testing easier (this also makes evolution and maintenance of your system easier too).

For developers, the implication is that they need to learn how to write effective unit tests. Beck’s experience is that good unit tests:

*

Run fast (they have short setups, run times, and break downs).
*

Run in isolation (you should be able to reorder them).
*

Use data that makes them easy to read and to understand.
*

Use real data (e.g. copies of production data) when they need to.
*

Represent one step towards your overall goal.

Virtual Circuits

Virtual Circuits

The connection through a Frame Relay network between two DTEs is called a virtual circuit (VC). The circuits are virtual because there is no direct electrical connection from end to end. The connection is logical, and data moves from end to end, without a direct electrical circuit. With VCs, Frame Relay shares the bandwidth among multiple users and any single site can communicate with any other single site without using multiple dedicated physical lines.

There are two ways to establish VCs:

SVCs, switched virtual circuits, are established dynamically by sending signaling messages to the network (CALL SETUP, DATA TRANSFER, IDLE, CALL TERMINATION).
PVCs, permanent virtual circuits, are preconfigured by the carrier, and after they are set up, only operate in DATA TRANSFER and IDLE modes. Note that some publications refer to PVCs as private VCs.



In the figure, there is a VC between the sending and receiving nodes. The VC follows the path A, B, C, and D. Frame Relay creates a VC by storing input-port to output-port mapping in the memory of each switch and thus links one switch to another until a continuous path from one end of the circuit to the other is identified. A VC can pass through any number of intermediate devices (switches) located within the Frame Relay network.

The question you may ask at this point is, "How are the various nodes and switches identified?"


VCs provide a bidirectional communication path from one device to another. VCs are identified by DLCIs. DLCI values typically are assigned by the Frame Relay service provider (for example, the telephone company). Frame Relay DLCIs have local significance, which means that the values themselves are not unique in the Frame Relay WAN. A DLCI identifies a VC to the equipment at an endpoint. A DLCI has no significance beyond the single link. Two devices connected by a VC may use a different DLCI value to refer to the same connection.

Locally significant DLCIs have become the primary method of addressing, because the same address can be used in several different locations while still referring to different connections. Local addressing prevents a customer from running out of DLCIs as the network grows.

This is the same network as presented in the previous figure, but this time, as the frame moves across the network, Frame Relay labels each VC with a DLCI. The DLCI is stored in the address field of every frame transmitted to tell the network how the frame should be routed. The Frame Relay service provider assigns DLCI numbers. Usually, DLCIs 0 to 15 and 1008 to 1023 are reserved for special purposes. Therefore, service providers typically assign DLCIs in the range of 16 to 1007.

In this example, the frame uses DLCI 102. It leaves the router (R1) using Port 0 and VC 102. At switch A, the frame exits Port 1 using VC 432. This process of VC-port mapping continues through the WAN until the frame reaches its destination at DLCI 201, as shown in the figure. The DLCI is stored in the address field of every frame transmitted.

PPP

What is PPP?

Recall that HDLC is the default serial encapsulation method when you connect two Cisco routers. With an added protocol type field, the Cisco version of HDLC is proprietary. Thus, Cisco HDLC can only work with other Cisco devices. However, when you need to connect to a non-Cisco router, you should use PPP encapsulation.

PPP encapsulation has been carefully designed to retain compatibility with most commonly used supporting hardware. PPP encapsulates data frames for transmission over Layer 2 physical links. PPP establishes a direct connection using serial cables, phone lines, trunk lines, cellular telephones, specialized radio links, or fiber-optic links. There are many advantages to using PPP, including the fact that it is not proprietary. Moreover, it includes many features not available in HDLC:

The link quality management feature monitors the quality of the link. If too many errors are detected, PPP takes the link down.
PPP supports PAP and CHAP authentication. This feature is explained and practiced in a later section.


PPP contains three main components:

HDLC protocol for encapsulating datagrams over point-to-point links.
Extensible Link Control Protocol (LCP) to establish, configure, and test the data link connection.
Family of Network Control Protocols (NCPs) for establishing and configuring different network layer protocols. PPP allows the simultaneous use of multiple network layer protocols. Some of the more common NCPs are Internet Protocol Control Protocol, Appletalk Control Protocol, Novell IPX Control Protocol, Cisco Systems Control Protocol, SNA Control Protocol, and Compression Control Protocol.

TDM

Time Division Multiplexing
Bell Laboratories invented time-division multiplexing (TDM) to maximize the amount of voice traffic carried over a medium. Before multiplexing, each telephone call required its own physical link. This was an expensive and unscalable solution. TDM divides the bandwidth of a single link into separate channels or time slots. TDM transmits two or more channels over the same link by allocating a different time interval (time slot) for the transmission of each channel. In effect, the channels take turns using the link.

TDM is a physical layer concept. It has no regard for the nature of the information that is being multiplexed onto the output channel. TDM is independent of the Layer 2 protocol that has been used by the input channels.

TDM can be explained by an analogy to highway traffic. To transport traffic from four roads to another city, you can send all the traffic on one lane if the feeding roads are equally serviced and the traffic is synchronized. So, if each of the four roads puts a car onto the main highway every four seconds, the highway gets a car at the rate of one each second. As long as the speed of all the cars is synchronized, there is no collision. At the destination, the reverse happens and the cars are taken off the highway and fed to the local roads by the same synchronous mechanism.

This is the principle used in synchronous TDM when sending data over a link. TDM increases the capacity of the transmission link by slicing time into smaller intervals so that the link carries the bits from multiple input sources, effectively increasing the number of bits transmitted per second. With TDM, the transmitter and the receiver both know exactly which signal is being sent.

In our example, a multiplexer (MUX) at the transmitter accepts three separate signals. The MUX breaks each signal into segments. The MUX puts each segment into a single channel by inserting each segment into a timeslot.

A MUX at the receiving end reassembles the TDM stream into the three separate data streams based only on the timing of the arrival of each bit. A technique called bit interleaving keeps track of the number and sequence of the bits from each specific transmission so that they can be quickly and efficiently reassembled into their original form upon receipt. Byte interleaving performs the same functions, but because there are eight bits in each byte, the process needs a bigger or longer time slot.

WAN Physical Layer Concepts

WAN Devices

WANs use numerous types of devices that are specific to WAN environments, including:

Modem-Modulates an analog carrier signal to encode digital information, and also demodulates the carrier signal to decode the transmitted information. A voiceband modem converts the digital signals produced by a computer into voice frequencies that can be transmitted over the analog lines of the public telephone network. On the other side of the connection, another modem converts the sounds back into a digital signal for input to a computer or network connection. Faster modems, such as cable modems and DSL modems, transmit using higher broadband frequencies.
CSU/DSU-Digital lines, such as T1 or T3 carrier lines, require a channel service unit (CSU) and a data service unit (DSU). The two are often combined into a single piece of equipment, called the CSU/DSU. The CSU provides termination for the digital signal and ensures connection integrity through error correction and line monitoring. The DSU converts the T-carrier line frames into frames that the LAN can interpret and vice versa.
Access server-Concentrates dial-in and dial-out user communications. An access server may have a mixture of analog and digital interfaces and support hundreds of simultaneous users.
WAN switch-A multiport internetworking device used in carrier networks. These devices typically switch traffic such as Frame Relay, ATM, or X.25, and operate at the data link layer of the OSI reference model. Public switched telephone network (PSTN) switches may also be used within the cloud for circuit-switched connections like Integrated Services Digital Network (ISDN) or analog dialup.
Router-Provides internetworking and WAN access interface ports that are used to connect to the service provider network. These interfaces may be serial connections or other WAN interfaces. With some types of WAN interfaces, an external device such as a DSU/CSU or modem (analog, cable, or DSL) is required to connect the router to the local point of presence (POP) of the service provider.
Core router-A router that resides within the middle or backbone of the WAN rather than at its periphery. To fulfill this role, a router must be able to support multiple telecommunications interfaces of the highest speed in use in the WAN core, and it must be able to forward IP packets at full speed on all of those interfaces. The router must also support the routing protocols being used in the core.

WAN Technology Overview

WANs and the OSI Model

As described in relation to the OSI reference model, WAN operations focus primarily on Layer 1 and Layer 2. WAN access standards typically describe both physical layer delivery methods and data link layer requirements, including physical addressing, flow control, and encapsulation. WAN access standards are defined and managed by a number of recognized authorities, including the International Organization for Standardization (ISO), the Telecommunication Industry Association (TIA), and the Electronic Industries Alliance (EIA).

The physical layer (OSI Layer 1) protocols describe how to provide electrical, mechanical, operational, and functional connections to the services of a communications service provider.

The data link layer (OSI Layer 2) protocols define how data is encapsulated for transmission toward a remote location and the mechanisms for transferring the resulting frames. A variety of different technologies are used, such as Frame Relay and ATM. Some of these protocols use the same basic framing mechanism, High-Level Data Link Control (HDLC), an ISO standard, or one of its subsets or variants.

The Evolving Network Model

The Hierarchical Design Model

The hierarchical network model is a useful high-level tool for designing a reliable network infrastructure. It provides a modular view of a network, making it easier to design and build a scalable network.

The Hierarchical Network Model

As you may recall from CCNA Exploration: LAN Switching and Wireless, the hierarchical network model divides a network into three layers:

Access layer-Grants user access to network devices. In a network campus, the access layer generally incorporates switched LAN devices with ports that provide connectivity to workstations and servers. In the WAN environment, it may provide teleworkers or remote sites access to the corporate network across WAN technology.
Distribution layer-Aggregates the wiring closets, using switches to segment workgroups and isolate network problems in a campus environment. Similarly, the distribution layer aggregates WAN connections at the edge of the campus and provides policy-based connectivity.
Core layer (also referred to as the backbone) - A high-speed backbone that is designed to switch packets as fast as possible. Because the core is critical for connectivity, it must provide a high level of availability and adapt to changes very quickly. It also provides scalability and fast convergence.


The figure represents the Hierarchical Network Model in campus environments. The Hierarchical Network Model provides a modular framework that allows flexibility in network design, and facilitates ease of implementation and troubleshooting in the infrastructure. However, it is important to understand that the network infrastructure is only the foundation to a comprehensive architecture.

Networking technologies have advanced considerably in recent years, resulting in networks that are increasingly intelligent. The current network elements are more aware of traffic characteristics and can be configured to deliver specialized services based on such things as the types of data they carry, the priority of the data, and even the security needs. Although most of these various infrastructure services are outside the scope of this course, it is important to understand that they influence network design. In the next topic, we will explore the Cisco Enterprise Architecture, which expands upon the hierarchical model by making use of network intelligence to address the network infrastructure.

What is a WAN?

What is a WAN?

A WAN is a data communications network that operates beyond the geographic scope of a LAN.

WANs are different from LANs in several ways. While a LAN connects computers, peripherals, and other devices in a single building or other small geographic area, a WAN allows the transmission of data across greater geographic distances. In addition, an enterprise must subscribe to a WAN service provider to use WAN carrier network services. LANs are typically owned by the company or organization that uses them.

WANs use facilities provided by a service provider, or carrier, such as a telephone or cable company, to connect the locations of an organization to each other, to locations of other organizations, to external services, and to remote users. WANs generally carry a variety of traffic types, such as voice, data, and video.

Here are the three major characteristics of WANs:

WANs generally connect devices that are separated by a broader geographical area than can be served by a LAN.
WANs use the services of carriers, such as telephone companies, cable companies, satellite systems, and network providers.
WANs use serial connections of various types to provide access to bandwidth over large geographic areas.


Why Are WANs Necessary?

LAN technologies provide both speed and cost-efficiency for the transmission of data in organizations over relatively small geographic areas. However, there are other business needs that require communication among remote sites, including the following:

People in the regional or branch offices of an organization need to be able to communicate and share data with the central site.
Organizations often want to share information with other organizations across large distances. For example, software manufacturers routinely communicate product and promotion information to distributors that sell their products to end users.
Employees who travel on company business frequently need to access information that resides on their corporate networks.


In addition, home computer users need to send and receive data across increasingly larger distances. Here are some examples:

It is now common in many households for consumers to communicate with banks, stores, and a variety of providers of goods and services via computers.
Students do research for classes by accessing library indexes and publications located in other parts of their country and in other parts of the world.


Since it is obviously not feasible to connect computers across a country or around the world in the same way that computers are connected in a LAN with cables, different technologies have evolved to support this need. Increasingly, the Internet is being used as an inexpensive alternative to using an enterprise WAN for some applications. New technologies are available to businesses to provide security and privacy for their Internet communications and transactions. WANs used by themselves, or in concert with the Internet, allow organizations and individuals to meet their wide-area communication needs.

Benefits and Limitation of E-Commerce

The Benefits of EC
Few innovations in human history encompass as many potential benefits as EC does. The global nature of the technology, low cost, opportunity to reach hundreds of millions of people, interactive nature, variety of possibilities, and resourcefulness and rapid growth of the supporting infrastructures result in many potential benefits are just starting to materialize, but they will increase significantly as EC expands. It is not surprising that some maintain that the EC revolution is just “as profound as the change that came with the industrial revolution”.
Benefits to Organizations:
The benefits to organizations are as follows:
1. EC expands the marketplace to national and international markets. With minimal capital outlay, a company can easily and quickly locate more customers, the best suppliers, and the most suitable business partners worldwide.
2. EC decreases the cost of creating, processing, distributing, storing, and retrieving paper-based information.
3. Ability for creating highly specialized businesses.
4. EC allows reduced inventories and overhead by facilitating “pull” –type supply chain management. In a pull-type system the process starts from customer orders and uses just in time manufacturing.
5. The pull-type processing enables expensive customization of products and services which provides competitive advantage to its implementers.
6. EC reduces the time between the outlay of capital and the receipt of products and services.
7. EC initiates business processes reengineering projects.
8. EC lowers telecommunications cost –the Internet is much cheaper than VANs.
9. Other benefits include improved image, improved customer service, new found business partners, simplified processes, compressed cycle and delivery time, increased productivity, eliminating paper, expediting access to information, reduced transportation costs, and increased flexibility.

Benefits to Consumers
The benefits of EC to consumers are as follows:
1. EC enables customers to shop or do other transactions 24 hours a day, all year round, from almost any location.
2. EC provides customers with more choice; they can select from many vendors and from more products.
3. EC frequently provides customers with less expensive products and services by allowing them to shop in many places and conduct quick comparisons.
4. In some case, especially with digitized products, EC allows quick delivery.
5. Customer can receive relevant and detailed information in seconds, rather than days or weeks.
6. EC makes it possible to participate in virtual auctions.
7. EC allows customers to interact with other customers in electronic communities and exchange ideas as well as compare experiences.
8. EC facilitates competition, which results in substantial discounts.

Benefits to Society
The benefits of EC to society are as follows:
1. EC enables more individuals to work at home and to do less traveling for shopping, resulting in less traffic on the roads and lower air pollution.
2. EC allows some merchandise to be sold at lower prices, so less affluent people can buy more and increase their standard of living.
3. EC enables people in third world countries and rural areas to enjoy products and services that otherwise are not available to them. This includes opportunities to learn professions and earn college degrees.
4. EC facilitates delivery of public services, such as health care, education, and distribution of government social services at a reduced cost and/or improved quality. Health-care services, for example, can reach patients in rural areas.

The limitations of EC
The limitations of EC can be grouped into technical and nontechnical categories.
Technical Limitations of EC
The technical limitations of EC are as follows:
1. There is a lack of system security, reliability, standards, and some communication protocols.
2. There is insufficient telecommunication bandwidth.
3. There is software development tools are still evolving and changing rapidly.
4. It is difficult to integrate the internet and EC software with some existing applications and databases.
5. Vendors may need special Web servers and other infrastructures.
6. Some EC software might not fit with some hardware, or may be incompatible with some operating systems or other components.
These limitations will lessen or be overcome; appropriate planning can minimize their impact.
Nontechnical Limitations
There are many nontechnical limitations that slow spread of EC; the following are the major ones:
1. Cost and Justification
2. Security and Privacy
3. Lack of trust and user resistance
4. Other limiting factors

#include palash.h

/* include Palash.h*/

#define BSIZE 128 /* buffer size */
#define NONE -1
#define EOS '\0'


#define NUM 256
#define DIV 257
#define MOD 258
#define ID 259
#define DONE 260


#define IF 261
#define THEN 262
#define ELSE 263
#define WHILE 264
#define REPEAT 265
#define UNTIL 266

#define BEGIN 267
#define END 268
#define INT 269
#define CHAR 270
#define WS 271
#define NID 272
#define DO 273

#define STRMAX 999 /* size of lexemes array */
#define SYMMAX 100 /* size of symtable */
#define MAX 10000

Compiler Using C

/* Palash.cseku@gmail.com */
#include /* load i/o routines */
#include
#include
#include /* load character test routines */
#include Palash.h

FILE *fp,*fout;
char lexemes[STRMAX];
char Terror[20][50];
char line[20],err[50],str[30];
int lastchar = -1; /* last used position in lexemes */

int lastentry = 0; /* last used position in symtable*/
int inc=0,flag=0,gb,gt;
int lookahead,q=2,chkParen=0,chkBegin=0,Int=0;

char lexbuf[BSIZE];
int lineno = 1,check=0;
int tokenval = NONE;

void match(int);
void expr();
void term();
void factor();
void stmt();
void error(char[]);
void emit(int,int);
struct entry /* form of symbol table entry */
{
 char *lexptr;
 int token;

};
struct entry symtable[SYMMAX];
char *allToken[1000];

//struct entry keywords[]={0,0};

struct entry keywords[]={"div",DIV,
  "mod",MOD,
  "if",IF,
  "then",THEN,
  "else",ELSE,
  "do",DO,
  "while",WHILE,
  "repeat",REPEAT,
  "until",UNTIL,
  "begin",BEGIN,
  "end",END,
  "int",INT,
  "char",CHAR,
  0,0
  };

void init()
{
 struct entry *p;
 for(p=keywords; p->token; p++)
  insert(p->lexptr,p->token);
}



void expr()
{
 lookahead = lexan();
 while(lookahead != DONE)
 switch(lookahead)
 {
  case ';' : if(chkParen>0)error(" ) required");
  else if(chkParen<0)error(" chkparen="0;" q="="0)" lookahead="="INT||lookahead="="CHAR||lookahead="="NUM||lookahead="="ID)">'&&lookahead!='='&&lookahead!=NUM&& lookahead!=ID)
  error(" <>' :
  match('>');
  if(lookahead!='='&&lookahead!=NUM&& lookahead!=ID)
  error(" > error");
  break;

  case NUM : match(NUM);
  if(lookahead=='(' )
  error(" NUM error");
  break;
  case ID : match(ID);
  if(lookahead=='('&& lookahead!=INT&& lookahead!=CHAR)
  error("ID error ");
  break;
  case IF : match(IF);match('(');expr();match(')');
  if(lookahead!=THEN)error("Required then");
  break;
  case THEN : match(THEN);
  if(lookahead!=IF&&lookahead!=ID&&lookahead!=ELSE)
  error("if or else or identifier required");
  break;
  case ELSE : match(ELSE);
  if(lookahead!=IF&&lookahead!=ID)
  error("If or id required");
  break;
  case DO : match(DO);
  break;
  case WHILE : match(WHILE);
  break;
  case REPEAT : match(REPEAT);
  break;
  case UNTIL : match(UNTIL);
  break;
  case BEGIN : chkBegin++;
  match(BEGIN);
  break;
  case END : chkBegin--;
  match(END);
  break;
  case INT : Int=1;
  if(q==0)
  {
  insert(str,ID);
  check=0;q=1;
  }
  else error("Duplicate declaration");
  match(INT);
  match(';');
  Int=0;
  break;
  case CHAR : if(q==0)

  {
  insert(str,ID);
  check=0;q=1;
  }
  else error("Duplicate declaration");
  match(CHAR);
  match(';');

  break;
  default :
  error("Unexpected");
  getch();exit(0);
 }

}

int lexan() /* lexixcal analyzer */
{
 int t;
 while(1)
 {
  t = getc(fp);
  if(t == ' '|| t == '\t') ; /* strip out white space */

  else if(t == '\n')
  {
  lineno = lineno + 1;

  }

  else if( isdigit(t))
  {
  ungetc(t,fp);
  scanf("%d",&tokenval);
  return NUM;
  }

  else if( isalpha(t)) /* t is a letter */
  {

  int p,b=0;

  while(isalnum(t)) /* t is a alphanumeric */
  {
  lexbuf[b]=t;
  t=getc(fp);
  b= b + 1;
  if(b >= BSIZE) error("compiler error");
  }

  lexbuf[b] = EOS;

  if(t != EOF)
  ungetc(t,fp);

  p = lookup(lexbuf);

  if(p == 0)
  {
  q=p;
  strcpy(str,lexbuf);
  return ID;
  }
  else check=1;

  tokenval = p;
  return symtable[p].token;
  }

  else if(t ==EOF) return DONE;

  else
  {
  tokenval = NONE;
  return t;
  }

 }
}


void main()
{
 clrscr();
 init();
 fp=fopen("in.cpp","r");
 fout=fopen("out.cpp","w");
 expr();
 if(chkBegin>0){error(" end required");getch();}
 else if(chkBegin<0){error(" int="="1)" lookahead =" lexan();" p =" lastentry;">0 ;p = p-1)
  if(strcmp(symtable[p].lexptr,s) == 0)
  return p;
 return 0;
}


int insert(char s[], int tok)
{
 int len;
 len = strlen(s);
 if(lastentry + 1 >=SYMMAX) error("symbol table full");
 if(lastchar + len +1 >= STRMAX) error("lexemes array full");
 lastentry = lastentry + 1;
 symtable[lastentry].token = tok;
 symtable[lastentry].lexptr = &lexemes[lastchar + 1];
 lastchar = lastchar + len +1;
 strcpy(symtable[lastentry].lexptr,s);
 return lastentry;
}

void error(char *m)
{
 //fprintf(stderr,"line %d: %s\n",lineno,m);
 fprintf(fout,"line %d: %s\n",lineno,m);
}

Chinese Remainder Theorem

Chinese Remainder Theorem 

The Chinese Remainder Theorem is mainly based on the algorithm of linear congruencies. Congruence is nothing more than a statement about divisibility [19]. The Chinese Remainder Theorem is mainly based on the system of linear congruencies a = b (mod n) which can be reduced to a set of a = b (mod ni), where n1, n2, Ö ni are prime factors of n.

Theorem
Let n1, n2, . . . ,nk denote k positive integers which are relatively prime, and let a1,a2, . . . , ak denote any k integers. Then the congruencies x = ai (mod ni), i = 1, 2. . . k have common solutions. Any two solutions are congruent modulo n1, n2. . . nk. 
  Y = X (mod P) where P = n1* n2*Ö.* nk.  
  X = (a1*N1*x1) + . . . .+ (ak*Nk*xk) (mod P) 
  i.e. X = ∑ ai*Ni*xi (Mod P)  
Where Nk = P / nk in which xk satisfies Ni*xi = 1 (mod ni). 
The remainder of the solved congruencies X is transmitted. At the receiving end, using X, ai are found using ai = X (mod ni) and then multiplying by16, the original pixel values are reconstructed.

Operating System

palash.cseku@gmail.com
http://shahidul-haque-palash.blogspot.com


Deadlocks---------
MUL_DEAD



#include
#include

#define MAX 50

int n; //no of process

int m; //no of resources

int process_completed=0;

int marked[MAX]={0};


int E[MAX+1];

int A[MAX+1];

int C[MAX+1][MAX+1]={0};

int R[MAX+1][MAX+1]={0};



int match_request(int p)
{


for(int j=0;j {

if( A[j] < R[p][j]) return 0;

}



return 1;

}



void terminate_collect(int p)
{


for(int i=0;i {
A[i]=C[p][i]+A[i];

}

marked[p]=1;

printf("\nCompleted process: %d",p);

process_completed++;

}






void main()
{


printf("\nenter the no of processes\n");

scanf("%d",&n);

printf("\nenter the no of resources\n");

scanf("%d",&m);

//E input
printf("\nenter the Existing resource vector : %d elements \n",m);

for(int i=0;i

//A input

printf("\nenter the Available resources vecor : %d elements \n",m);

for(i=0;i




//C input
printf("\nenter the Current Allocation matrix : %d * %d elements\n",n,m);


for(i=0;i {

for(int j=0;j {

int value;

scanf("%d",&value);

C[i][j]=value;

}

}


//request matrix

printf("\nenter the request matrix %d * %d element\n",n,m);

for( i=0;i {
for(int j=0;j {

int value;

scanf("%d",&value);

R[i][j]=value;


}

}



///execution starts here


int turn=0;

while(1)
{


for(int i=0;i {

if( match_request(i) && !marked[i] )

{

terminate_collect(i);

}


}

turn++;


if(process_completed==n)
{
printf("\n No deadlock here.\n");

return;

}

else if(turn >n+1)
{

printf("\nThere is a deadlock\n");

return;

}
}
}

CCNA 3:Module 5

Options With ## are Correct Answer

palash.cseku@gmail.com
http://shahidul-haque-palash.blogspot.com


1. Which two statements are true about the default operation of STP in a Layer 2 switched environment that has redundant connections between switches? (Choose two.)
The root switch is the switch with the highest speed ports.
##Decisions on which port to block when two ports have equal cost depend on the port priority and identity.
All trunking ports are designated and not blocked.
Root switches have all ports set as root ports.
##Non-root switches each have only one root port.
2. Which two statements describe the BIDs used in a spanning tree topology? (Choose two.)
They are sent out by the root bridge only after the inferior BPDUs are sent.
##They consist of a bridge priority and MAC address.
Only the root bridge will send out a BID.
##They are used by the switches in a spanning tree topology to elect the root bridge.
The switch with the fastest processor will have the lowest BID.

3. In which two ways is the information that is contained in BPDUs used by switches? (Choose two.)
to negotiate a trunk between switches
to set the duplex mode of a redundant link
##to identify the shortest path to the root bridge
to prevent loops by sharing bridging tables between connected switches
##to determine which ports will forward frames as part of the spanning tree
4. Which two actions does an RSTP edge port take if it receives a BPDU? (Choose two.)
##immediately loses its edge status
inhibits the generation of a TCN
goes immediately to a learning state
disables itself
##becomes a normal spanning-tree port
5. Refer to the exhibit. All switches in the network have empty MAC tables. STP has been disabled on the switches in the network. How will a broadcast frame that is sent by host PC1 be handled on the network?
Switch SW1 will block the broadcast and drop the frame.
##Switch SW1 will forward the broadcast out all switch ports, except the originating port. This will generate an endless loop in the network.
Switch SW1 will forward the broadcast out all switch ports, except the originating port. All hosts in the network will replay with a unicast frame sent to host PC1.
Switch SW1 will forward the traffic out all switch ports except the originating port as a unicast frame. All hosts in the network will replay with a unicast frame sent to switch SW1.
6. Which two items are true regarding the spanning-tree portfast command? (Choose two.)
##PortFast is Cisco proprietary.
PortFast can negatively effect DHCP services.
PortFast is used to more quickly prevent and eliminate bridging loops.
Enabling PortFast on trunks that connect to other switches improves convergence.
##If an access port is configured with PortFast, it immediately transitions from a blocking to a forwarding state.

7. Refer to the exhibit. Server sends an ARP request for the MAC address of its default gateway. If STP is not enabled, what will be the result of this ARP request?
Router_1 will drop the broadcast and reply with the MAC address of the next hop router.
Switch_A will reply with the MAC address of the Router_1 E0 interface.
##Switch_A and Switch_B will continuously flood the message onto the network.
The message will cycle around the network until its TTL is exceeded.
8. What is the first step in the process of convergence in a spanning tree topology?
##election of the root bridge
blocking of the non-designated ports
selection of the designated trunk port
determination of the designated port for each segment
9. How can a network administrator influence which STP switch becomes the root bridge?
Configure all the interfaces on the switch as the static root ports.
Change the BPDU to a lower value than that of the other switches in the network.
Assign a lower IP address to the switch than that of the other switches in the network.
##Set the switch priority to a smaller value than that of the other switches in the network.


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10. Refer to the exhibit. The spanning-tree port priority of each interface is at the default setting. The network administrator enters the spanning-tree vlan 1 root primary command on S4. What is the effect of the command?
Spanning tree blocks Gi0/1 on S3.
##Gi0/2 on S3 transitions to a root port.
Port priority makes Gi0/2 on S1 a root port.
S4 is already the root bridge, so there are no port changes.
11. What two features of the Spanning-Tree Protocol contribute to the time it takes for a switched network to converge after a topology change occurs? (Choose two.)
##the max-age timer
the spanning-tree hold down timer
##the forward delay
the spanning-tree path cost
the blocking delay
12. In which STP state does a port record MAC addresses but not forward user data?
blocking
##Learning
disabling
listening
forwarding

13. Which three statements are accurate regarding RSTP and STP? (Choose three.)
RSTP uses a faster algorithm to determine root ports.
RSTP introduced the extended system ID to allow for more than 4096 VLANs.
##Both RSTP and STP use the portfast command to allow ports to immediately transition to forwarding state.
Like STP PortFast, an RSTP edge port that receives a BPDU loses its edge port status immediately and becomes a normal spanning-tree port.
##Configuration commands to establish primary and secondary root bridges are identical for STP and RSTP.
##Because of the format of the BPDU packet, RSTP is backward compatible with STP.
14. What two elements will exist in a converged network with one spanning tree? (Choose two.)
##one root bridge per network
all non-designated ports forwarding
##one root port per non-root bridge
multiple designated ports per segment
one designated port per network

15. Which statement or set of paired statements correctly compares STP with RSTP?
STP and RSTP use the same BPDU format.
STP specifies backup ports. RSTP has only root ports, alternate ports, and designated ports.
STP port states are independent of port roles. RSTP ties together the port state and port role.
##STP waits for the network to converge before placing ports into forwarding state. RSTP places alternate ports into forwarding state immediately.

16. Refer to the exhibit. What can be determined from the output shown?
Two hosts communicating between ports Fa0/2 and Fa0/4 have a cost of 38.
##The priority was statically configured to identify the root.
STP is disabled on this switch.
The timers have been altered to reduce convergence time.

17. Which two criteria does a switch use to select the root bridge? (Choose two.)
##bridge priority
switching speed
number of ports
##base MAC address
switch location
memory size
18. What three link types have been defined for Rapid Spanning-Tree Protocol? (Choose three.)
##Shared
end-to-end
##edge-type
boundary-type
point-to-many
##point-to-point
19. What Rapid Spanning Tree Protocol (RSTP) role is assigned to the forwarding port elected for every switched Ethernet LAN segment?
alternate
backup
##Designated
root

20. When PVST+ was developed, the Bridge ID was modified to include which information?
bridge priority
MAC address
protocol
##VLAN ID

CCNA 3:Module 2

Options With ## are Correct Answer

palash.cseku@gmail.com
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1. When a switch receives a frame and the source MAC address is not found in the switching table, what action will be taken by the switch to process the incoming frame?
The switch will request that the sending node resend the frame.
The switch will issue an ARP request to confirm that the source exists.
##The switch will map the source MAC address to the port on which it was received.
The switch ends an acknowledgement frame to the source MAC of this incoming frame.

2. Refer to the exhibit. How many collision domains are depicted in the network?
1
##2
4
6
7
8
3. Refer to the exhibit. What action does SW1 take on a frame sent from PC_A to PC_C if the MAC address table of SW1 is empty?
SW1 drops the frame.
##SW1 floods the frame on all ports on SW1, except port Fa0/1.
SW1 floods the frame on all ports on the switch, except Fa0/23 and Fa0/1.
SW1 uses the CDP protocol to synchronize the MAC tables on both switches and then forwards the frame to all ports on SW2.
4. If a network administrator enters these commands in global configuration mode on a switch, what will be the result?
Switch1(config-line)# line console 0
Switch1(config-line)# password cisco
Switch1(config-line)# login
##to secure the console port with the password "cisco"
to deny access to the console port by specifying 0 lines are available
to gain access to line configuration mode by supplying the required password
to configure the privilege exec password that will be used for remote access

5. A network administrator uses the CLI to enter a command that requires several parameters. The switch responds with "% Incomplete command". The administrator cannot remember the missing parameters. What can the administrator do to get the parameter information?
append ? to the last parameter
##append a space and then ? to the last parameter
use Ctrl-P to show a parameter list
use the Tab key to show which options are available
6. Refer to the exhibit. The switch and the hub have default configurations, and the switch has built its CAM table. Which of the hosts will capture a copy of the frame when workstation A sends a unicast packet to workstation C?
##workstation C
workstations B and C
workstations A, B, C, and the interfaces of the router
workstations B, C, D, E, F, and interfaces of the router
7. Which two statements are true regarding switch port security? (Choose two.)
The three configurable violation modes all log violations via SNMP.
##Dynamically learned secure MAC addresses are lost when the switch reboots.
The three configurable violation modes all require user intervention to re-enable ports.
After entering the sticky parameter, only MAC addresses subsequently learned are converted to secure MAC addresses.
If fewer than the maximum number of MAC addresses for a port are configured statically, dynamically learned ##addresses are added to CAM until the maximum number is reached.
8. Refer to the exhibit. The exhibit shows partial output of the show running-config command. The enable password on this switch is "cisco." What can be determined from the output shown?
The enable password is encrypted by default.
An MD5 hashing algorithm was used on all encrypted passwords.
##Any configured line mode passwords will be encrypted in this configuration.
This line represents most secure privileged EXEC mode password possible.
9. What are two ways to make a switch less vulnerable to attacks like MAC address flooding, CDP attacks, and Telnet attacks? (Choose two.)
Enable CDP on the switch.
##Change passwords regularly.
##Turn off unnecessary services.
Enable the HTTP server on the switch.
Use the enable password rather than the enable secret password.

10. Refer to the exhibit. The switch and workstation are administratively configured for full-duplex operation. Which statement accurately reflects the operation of this link?
##No collisions will occur on this link.
Only one of the devices can transmit at a time.
The switch will have priority for transmitting data.
The devices will default back to half duplex if excessive collisions occur.

11. Where is the startup configuration stored?
DRAM
##NVRAM
ROM
startup-config.text
12. Refer to the exhibit. What happens when Host 1 attempts to send data?
##Frames from Host 1 cause the interface to shut down.
Frames from Host 1 are dropped and no log message is sent.
Frames from Host 1 create a MAC address entry in the running-config.
Frames from Host 1 will remove all MAC address entries in the address table.

13. Which statement is true about the command banner login "Authorized personnel Only" issued on a switch?
The command is entered in privileged EXEC mode.
##The command will cause the message Authorized personnel Only to display before a user logs in.
The command will generate the error message % Ambiguous command: "banner motd" ” to be displayed.
The command will cause the message End with the character “%” to be displayed after the command is entered into the switch.

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14. Refer to the exhibit. The network administrator’s attempts to connect to Switch1 via Secure Shell are failing. What is most likely the problem?
incorrect vty lines configured
incompatible Secure Shell version
incorrect default gateway address
##vty lines that are configured to allow only Telnet

15. What happens when the transport input ssh command is entered on the switch vty lines?
The SSH client on the switch is enabled.
##Communication between the switch and remote users is encrypted.
A username/password combination is no longer needed to establish a secure remote connection to the switch.
The switch requires remote connections via proprietary client software.

16. Which two statements about Layer 2 Ethernet switches are true? (Choose two.)
Layer 2 switches prevent broadcasts.
##Layer 2 switches have multiple collision domains.
Layer 2 switches route traffic between different networks.
Layer 2 switches decrease the number of broadcast domains.
##Layer 2 switches can send traffic based on the destination MAC address.
17. Refer to the exhibit. Which hosts will receive a broadcast frame sent from Host A?
hosts A and B
hosts B and C
hosts D and E
##hosts A, B, and C
hosts B, C, D, and E
hosts A, B, C, D, E, and F
18. Which command line interface (CLI) mode allows users to configure switch parameters, such as the hostname and password?
user EXEC mode
privileged EXEC mode
##global configuration mode
interface configuration mode

19. Which two statements are true about EXEC mode passwords? (Choose two.)
The enable secret password command stores the configured password in plain text.
##The enable secret password command provides better security than the enable password.
##The enable password and enable secret password protect access to privileged EXEC mode.
The service password-encryption command is required to encrypt the enable secret password.
Best practices require both the enable password and enable secret password to be configured and used simultaneously.

20. When a collision occurs in a network using CSMA/CD, how do hosts with data to transmit respond after the backoff period has expired?
##The hosts return to a listen-before-transmit mode.
The hosts creating the collision have priority to send data.
The hosts creating the collision retransmit the last 16 frames.
The hosts extend their delay period to allow for rapid transmission.

CCNA 3:Module 3

Options With ## are Correct Answer:
palash.cseku@gmail.com
http://shahidul-haque-palash.blogspot.com


1. What statement about the 802.1q trunking protocol is true?
802.1q is Cisco proprietary.
802.1q frames are mapped to VLANs by MAC address.
802.1q does NOT require the FCS of the original frame to be recalculated.
##802.1q will not perform operations on frames that are forwarded out access ports.


2. Which two statements describe the benefits of VLANs? (Choose two.)
VLANs improve network performance by regulating flow control and window size.
VLANs enable switches to route packets to remote networks via VLAN ID filtering.
VLANs reduce network cost by reducing the number of physical ports required on switches.
##VLANs improve network security by isolating users that have access to sensitive data and applications.
##VLANs divide a network into smaller logical networks, resulting in lower susceptibility to broadcast storms.

3. What are two characteristics of VLAN1 in a default switch configuration? (Choose two.)
VLAN1 should renamed.
##VLAN 1 is the management VLAN.
##All switch ports are members of VLAN1.
Only switch port 0/1 is assigned to VLAN1.
Links between switches must be members of VLAN1.

4. Refer to the exhibit. SW1 and SW2 are new switches being installed in the topology shown in the exhibit. Interface Fa0/1 on switch SW1 has been configured with trunk mode “on”. Which statement is true about forming a trunk link between the switches SW1 and SW2?
##Interface Fa0/2 on switch SW2 will negotiate to become a trunk link if it supports DTP.
Interface Fa0/2 on switch SW2 can only become a trunk link if statically configured as a trunk.
Interface Fa0/1 converts the neighboring link on the adjacent switch into a trunk link if the neighboring interface is configured in nonegotiate mode.
Interface Fa0/1 converts the neighboring link on the adjacent switch into a trunk link automatically with no consideration of the configuration on the neighboring interface.

5. Refer to the exhibit. Computer 1 sends a frame to computer 4. On which links along the path between computer 1 and computer 4 will a VLAN ID tag be included with the frame?
A
A, B
A, B, D, G
A, D, F
##C, E
C, E, F

6. The network administrator wants to separate hosts in Building A into two VLANs numbered 20 and 30. Which two statements are true concerning VLAN configuration? (Choose two.)
##The VLANs may be named.
VLAN information is saved in the startup configuration.
Non-default VLANs created manually must use the extended range VLAN numbers.
##The network administrator may create the VLANs in either global configuration mode or VLAN database mode.
Both VLANs may be named BUILDING_A to distinguish them from other VLANs in different geographical locations.

7. Refer to the exhibit. Which two conclusions can be drawn regarding the switch that produced the output shown? (Choose two.)
The network administrator configured VLANs 1002-1005.
The VLANs are in the active state and are in the process of negotiating configuration parameters.
A FDDI trunk has been configured on this switch.
##The command switchport access vlan 20 was entered in interface configuration mode for Fast Ethernet interface 0/1.
##Devices attached to ports fa0/5 through fa0/8 cannot communicate with devices attached to ports fa0/9 through fa0/12 without the use of a Layer 3 device.

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8. What happens to the member ports of a VLAN when the VLAN is deleted?
##The ports cannot communicate with other ports.
The ports default back to the management VLAN.
The ports automatically become a part of VLAN1.
The ports remain a part of that VLAN until the switch is rebooted. They then become members of the management VLAN.

9. A network administrator is removing several VLANs from a switch. When the administrator enters the no vlan 1 command, an error is received. Why did this command generate an error?
##VLAN 1 can never be deleted.
VLAN 1 can only be deleted by deleting the vlan.dat file.
VLAN 1 can not be deleted until all ports have been removed from it.
VLAN 1 can not be deleted until another VLAN has been assigned its responsibilities.

10. What is the effect of the switchport mode dynamic desirable command?
DTP cannot negotiate the trunk since the native VLAN is not the default VLAN.
The remote connected interface cannot negotiate a trunk unless it is also configured as dynamic desirable.
The connected devices dynamically determine when data for multiple VLANs must be transmitted across the link and bring the trunk up as needed.
##A trunk link is formed if the remote connected device is configured with the switchport mode dynamic auto or switchport mode trunk commands.

11. Refer to the exhibit. The exhibited configurations do not allow the switches to form a trunk. What is the most likely cause of this problem?
Cisco switches only support the ISL trunking protocol.
##The trunk cannot be negotiated with both ends set to auto.
By default, Switch1 will only allow VLAN 5 across the link.
A common native VLAN should have been configured on the switches.

12. Switch port fa0/1 was manually configured as a trunk, but now it will be used to connect a host to the network. How should the network administrator reconfigure switch port Fa0/1?
Disable DTP.
Delete any VLANs currently being trunked through port Fa0/1.
Administratively shut down and re-enable the interface to return it to default.
##Enter the switchport mode access command in interface configuration mode.

13. Refer to the exhibit. Computer B is unable to communicate with computer D. What is the most likely cause of this problem?
The link between the switches is up but not trunked.
VLAN 3 is not an allowed VLAN to enter the trunk between the switches.
The router is not properly configured to route traffic between the VLANs.
##Computer D does not have a proper address for the VLAN 3 address space.

14. Refer to the exhibit. The network administrator has just added VLAN 50 to Switch1 and Switch2 and assigned hosts on the IP addresses of the VLAN in the 10.1.50.0/24 subnet range. Computer A can communicate with computer B, but not with computer C or computer D. What is the most likely cause of this problem?
There is a native VLAN mismatch.
The link between Switch1 and Switch2 is up but not trunked.
The router is not properly configured for inter-VLAN routing.
##VLAN 50 is not allowed to entering the trunk between Switch1 and Switch2.

15. Refer to the exhibit. Which statement is true concerning interface Fa0/5?
The default native VLAN is being used.
The trunking mode is set to auto.
##Trunking can occur with non-Cisco switches.
VLAN information about the interface encapsulates the Ethernet frames.

16. What statements describe how hosts on VLANs communicate?
Hosts on different VLANs use VTP to negotiate a trunk.
##Hosts on different VLANs communicate through routers.
Hosts on different VLANs should be in the same IP network.
Hosts on different VLANs examine VLAN ID in the frame tagging to determine if the frame for their network.

17. Refer to the exhibit. How far is a broadcast frame that is sent by computer A propagated in the LAN domain?
none of the computers will receive the broadcast frame
computer A, computer B, computer C
computer A, computer D, computer G
computer B, computer C
##computer D, computer G
computer A, computer B, computer C, computer D, computer E, computer F, computer G, computer H, computer I

18. What is a valid consideration for planning VLAN traffic across multiple switches?
Configuring interswitch connections as trunks will cause all hosts on any VLAN to receive broadcasts from the other VLANs.
##A trunk connection is affected by broadcast storms on any particular VLAN that is carried by that trunk.
Restricting trunk connections between switches to a single VLAN will improve efficiency of port usage.
Carrying all required VLANs on a single access port will ensure proper traffic separation.

19. Which two statements about the 802.1q trunking protocol are true? (Choose two.)
802.1q is Cisco proprietary.
802.1q frames are mapped to VLANs by MAC address.
##If 802.1q is used on a frame, the FCS must be recalculated.
##802.1q will not perform operations on frames that are forwarded out access ports.
802.1q allows the encapsulation of the original frame to identify the VLAN from which a frame originated.

20. What switch port modes will allow a switch to successfully form a trunking link if the neighboring switch port is in "dynamic desirable" mode?
dynamic desirable mode
on or dynamic desirable mode
##on, auto, or dynamic desirable mode
on, auto, dynamic desirable, or nonegotiate mode

21. Refer to the exhibit. Company HR is adding PC4, a specialized application workstation, to a new company office. The company will add a switch, S3, connected via a trunk link to S2, another switch. For security reasons the new PC will reside in the HR VLAN, VLAN 10. The new office will use the 172.17.11.0/24 subnet. After installation, the existing PCs are unable to access shares on PC4. What is the likely cause?
The switch to switch connection must be configured as an access port to permit access to VLAN 10 on S3.
##The new PC is on a different subnet so Fa0/2 on S3 must be configured as a trunk port.
PC4 must use the same subnet as the other HR VLAN PCs.
A single VLAN cannot span multiple switches.

22. What must the network administrator do to remove Fast Ethernet port fa0/1 from VLAN 2 and assign it to VLAN 3?
Enter the no vlan 2 and the vlan 3 commands in global configuration mode.
##Enter the switchport access vlan 3 command in interface configuration mode.
Enter the switchport trunk native vlan 3 command in interface configuration mode.
Enter the no shutdown in interface configuration mode to return it to the default configuration and then configure the port for VLAN 3.

CCNA 3:Module 4

Options With ## are Correct Answer:

palash.cseku@gmail.com
http://shahidul-haque-palash.blogspot.com


1. Refer to the exhibit. The switches in the exhibit are connected with trunks within the same VTP management domain. Each switch is labeled with its VTP mode. A new VLAN is added to Switch3. This VLAN does not show up on the other switches. What is the reason for this?
VLANs cannot be created on transparent mode switches.
Transparent mode switches do not forward VTP advertisements.
##VLANs created on transparent mode switches are not included in VTP advertisements.
Server mode switches neither listen to nor forward VTP messages from transparent mode switches.
2. Which two statements are true about the implementation of VTP? (Choose two.)
##Switches must be connected via trunks.
##The VTP domain name is case sensitive.
Transparent mode switches cannot be configured with new VLANs.
The VTP password is mandatory and case sensitive.
Switches that use VTP must have the same switch name.
3. Which two statements describe VTP transparent mode operation? (Choose two.)
Transparent mode switches can create VLAN management information.
##Transparent mode switches can add VLANs of local significance only.
##Transparent mode switches pass any VLAN management information that they receive to other switches.
Transparent mode switches can adopt VLAN management changes that are received from other switches.
Transparent mode switches originate updates about the status of their VLANS and inform other switches about that status.
4. Which three VTP parameters must be identical on all switches to participate in the same VTP domain? (Choose three.)
revision number
##domain name
pruning
mode
##domain password
##version number

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5. What causes a VTP configured switch to issue a summary advertisement?
##A five-minute update timer has elapsed.
A port on the switch has been shutdown.
The switch is changed to the transparent mode.
A new host has been attached to a switch in the management domain.

6. Refer to the exhibit. Switches SW1 and SW2 are interconnected via a trunk link but failed to exchange VLAN information. The network administrator issued the show vtp status command to troubleshoot the problem. On the basis of the provided command output, what could be done to correct the problem?
Switch SW2 must be configured as a VTP client.
The switches must be interconnected via an access link.
##The switches must be configured with the same VTP domain name.
Both switches must be configured with the same VTP revision number.
7. Refer to the exhibit. Which two facts can be confirmed by this output? (Choose two.)
##If this switch is added to an established network, the other VTP-enabled switches in the same VTP domain will consider their own VLAN information to be more recent than the VLAN information advertised by this switch.
This switch shows no configuration revision errors.
This switch has established two-way communication with the neighboring devices.
##This switch is configured to advertise its VLAN configuration to other VTP-enabled switches in the same VTP domain.
This switch is configured to allows the network manager to maximize bandwidth by restricting traffic to specific network devices.
8. Refer to the exhibit. Switch S1 is in VTP server mode. Switches S2 and S3 are in client mode. An administrator accidentally disconnects the cable from F0/1 on S2. What will the effect be on S2?
S2 will automatically transition to VTP transparent mode.
S2 will remove all VLANs from the VLAN database until the cable is reconnected.
##S2 will retain the VLANs as of the latest known revision, but will lose the VLANs if it is reloaded.
S2 will automatically send a VTP request advertisement to 172.17.99.11 when the cable is reconnected.
9. Refer to the exhibit. What information can be learned from the output provided?
It verifies the configured VTP password.
It verifies the VTP domain is configured to use VTP version 2.
##It verifies VTP advertisements are being exchanged.
It verifies the VTP domain name is V1.

10. How are VTP messages sent between switches in a domain?
Layer 2 broadcast
##Layer 2 multicast
Layer 2 unicast
Layer 3 broadcast
Layer 3 multicast
Layer 3 unicast
11. What statement describes the default propagation of VLANs on a trunked link?
only VLAN 1
##all VLANs
no VLANs
the native VLAN
12. Which two statements are true about VTP pruning? (Choose two.)
Pruning is enabled by default.
##Pruning can only be configured on VTP servers.
Pruning must be configured on all VTP servers in the domain.
VLANs on VTP client-mode switches will not be pruned.
##Pruning will prevent unnecessary flooding of broadcasts across trunks.

13. What does a client mode switch in a VTP management domain do when it receives a summary advertisement with a revision number higher than its current revision number?
It suspends forwarding until a subset advertisement update arrives.
##It issues an advertisement request for new VLAN information.
It increments the revision number and forwards it to other switches.
It deletes the VLANs not included in the summary advertisement.
It issues summary advertisements to advise other switches of status changes.
14. Refer to the exhibit. All switches in the network participate in the same VTP domain. What happens when the new switch SW2 with a default configuration and revision number of 0 is inserted in the existing VTP domain Lab_Network?
The switch operates as a VTP client.
The switch operates in VTP transparent mode.
The switch operates as a VTP server and deletes the existing VLAN configuration in the domain.
##The switch operates as a VTP server, but does not impact the existing VLAN configuration in the domain.
The switch operates as a VTP server in the default VTP domain and does not affect the configuration in the existing VTP domain.
15. What are two features of VTP client mode operation? (Choose two.)
##unable to add VLANs
can add VLANs of local significance
forward broadcasts out all ports with no respect to VLAN information
can only pass VLAN management information without adopting changes
##can forward VLAN information to other switches in the same VTP domain

16. Refer to the exhibit. S2 was previously used in a lab environment and has been added to the production network in server mode. The lab and production networks use the same VTP domain name, so the network administrator made no configuration changes to S2 before adding it to the production network. The lab domain has a higher revision number. After S2 was added to the production network, many computers lost network connectivity. What will solve the problem?
Reset the revision number on S2 with either the delete VTP command or by changing the domain name and then changing it back.
##Re-enter all appropriate VLANs, except VLAN 1, manually on Switch1 so that they propagate throughout the network.*
Change S1 to transparent VTP mode to reclaim all VLANs in vlan.dat and change back to server mode.
Change S2 to client mode so the VLANs will automatically propagate.
17. A network administrator is replacing a failed switch with a switch that was previously on the network. What precautionary step should the administrator take on the replacement switch to avoid incorrect VLAN information from propagating through the network?
Enable VTP pruning.
##Change the VTP domain name.
Change the VTP mode to client.
Change all the interfaces on the switch to access ports.

18. Refer to the exhibit. Switch1 is not participating in the VTP management process with the other switches that are shown in the exhibit. What are two possible explanations for this? (Choose two.)
Switch1 is in client mode.
Switch2 is in server mode.
Switch2 is in transparent mode.
##Switch1 is in a different management domain.
Switch1 has end devices that are connected to the ports.
##Switch1 is using VTP version 1, and Switch2 is using VTP version 2.
19. Refer to the exhibit. All switches in the VTP domain are new. Switch SW1 is configured as a VTP server, switches SW2 and SW4 are configured as VTP clients, and switch SW3 is configured in VTP transparent mode. Which switch or switches receive VTP updates and synchronize their VLAN configuration based on those updates?
All switches receive updates and synchronize VLAN information.
Only switch SW2 receives updates and synchronizes VLAN information.
Only switches SW3 and SW4 receive updates and synchronize VLAN information.
##SW3 and SW4 receive updates, but only switch SW4 synchronizes VLAN information.
20. Which statement is true when VTP is configured on a switched network that incorporates VLANs?
VTP is only compatible with the 802.1Q standard.
VTP adds to the complexity of managing a switched network.
VTP allows a switch to be configured to belong to more than one VTP domain.
##VTP dynamically communicates VLAN changes to all switches in the same VTP domain.

CCNA 3:Module 1

Options With ## are Correct Answer

1. A network technician is asked to examine an existing switched network. Following this examination, the technician makes recommendations for adding new switches where needed and replacing existing equipment that hampers performance. The technician is given a budget and asked to proceed. Which two pieces of information would be helpful in determining necessary port density for new switches? (Choose two.)
forwarding rate
##traffic flow analysis palash.cseku@gmail.com
##expected future growth http://shahidul-haque-palash.blogspot.com
number of required core connections
number of hubs that are needed in the access layer to increase performance

2. Configuring communication between devices on different VLANs requires the use of which layer of the OSI model?
Layer 1
##Layer 3
Layer 4
Layer 5
3. What is the likely impact of moving a conventional company architecture to a completely converged network?
Local analog phone service can be completely outsourced to cost-effective providers.
The Ethernet VLAN structure is less complex.
##A shared infrastructure is created resulting in a single network to manage.
QoS issues are greatly reduced.
There is less bandwidth competition between voice and video streams
4. Which hierarchical design model layer controls the flow of network traffic using policies and delineates broadcast domains by performing routing functions between virtual LANs (VLANs)?
application
access
##distribution
network
core
5. A network administrator is selecting a switch that will operate at the network core. Which three features should the switch support for optimum network performance and reliability? (Choose three.)
port security
security policies
##10 Gigabit Ethernet
##quality of service (QoS)
##hot-swappable hardware
Power over Ethernet (PoE)
6. Which three features are commonly supported at the distribution layer of the Cisco hierarchical network model? (Choose three.)
##security policies
Power over Ethernet
switch port security
##quality of service
##Layer 3 functionality
end user access to network
7. Which two features are supported at all three levels of the Cisco three-layer hierarchical model? (Choose two.)
Power over Ethernet
load balancing across redundant trunk links
redundant components
##Quality of Service
##link aggregation

8. Which two characteristics are associated with enterprise level switches? (Choose two.)
low port density
##high forwarding rate
high latency level
##support link aggregation
predefined number of ports
9. Link aggregation should be implemented at which layer of the hierarchical network?
core only
distribution and core
access and distribution
##access, distribution, and core
10. For organizations that are implementing a voice over IP solution, what functionality should be enabled at all three layers of the hierarchical network?
Power over Ethernet
##quality of service
switch port security
inter-VLAN routing
11. Which layer of the hierarchical design model provides a means of connecting devices to the network and controlling which devices are allowed to communicate on the network?
application
##access
distribution
network
core
12. At which heirarchical layer are switches normally not required to process all ports at wire speed?
core layer
distribution layer
##access layer
entry layer
13. Which layer of the OSI model does an access layer LAN switch use to make a forwarding decision?
Layer 1
##Layer 2
Layer 3
Layer 4
14. Refer to the exhibit. What characteristic of hierarchical network designs is exhibited by having SW3 connected to both SW1 and Sw2?
scalability
security
##redundancy
maintainability
15. Which layer of the hierarchical network design model is refered to as the high-speed backbone of the internetwork, where high availability and redundancy are critical?
access layer
##core layer
data-link layer
distribution layer
network layer
physical layer
16. What statement best describes a modular switch?
a slim-line chassis
allows interconnection of switches on redundant backplane
defined physical characteristics
##flexible characteristics
17. A technician is attempting to explain Cisco StackWise technology to a client that is setting up three stackable switches. Which explanation accurately describes StackWise technology?
StackWise technology allows up to eight ports to be bound together to increase available bandwidth.
StackWise technology allows the switch to deliver power to end devices by using existing Ethernet cabling.
StackWise technology allows the switch capabilities and ports to be expanded by the addition of line cards.
##StackWise technology allows up to nine switches to be interconnected via the use of a fully redundant backplane.

18. Which hierarchical design characteristic would be recommended at both the core and distribution layers to protect the network in the case of a route failure?
PoE
##redundancy
aggregation
access lists

19. Which feature supports higher throughput in switched networks by combining multiple switch ports?
convergence
redundant links
##link aggregation
network diameter
20. Refer to the exhibit. Beginning with HR servers and workstations, a network engineer is designing a new security structure for the network. Which set of policies adheres to the hierarchical network model design principles?

Implement Layer 3 switching on S1 to reduce the packet processing load on D1 and D2. Install all security processing on S1 to reduce network traffic load.

##Configure port security options on S1. Use Layer 3 access control features on D1 and D2 to limit access to the HR servers to just the HR subnet.

Move all HR assets out of the data center and connect them to S1. Use Layer 3 security functions on S1 to deny all traffic into and out of S1.

Perform all port access and Layer 3 security functions on C1.

Dividing Hosts into Groups

Hierarchical Addressing

To be able to divide networks, we need hierarchical addressing. A hierarchical address uniquely identifies each host. It also has levels that assist in forwarding packets across internetworks, which enables a network to be divided based on those levels.

To support data communications between networks over internetworks, Network layer addressing schemes are hierarchical.

As shown in the figure, postal addresses are prime examples of hierarchical addresses.

Consider the case of sending a letter from Japan to an employee working at Cisco Systems, Inc.

The letter would be addressed:

Employee Name

Cisco Systems, Inc.

170 West Tasman Drive

San Jose, CA 95134

USA

When a letter is posted in the country of origin, the postal authority would only look at the destination country and note that the letter was destined for the U.S. No other address details need to be processed at this level.Upon arrival in the U.S., the post office first looks at the state, California. The city, street, and company name would not be examined if the letter still needed to be forwarded to the correct state. Once in California, the letter would be directed to San Jose. There the local mail carrier would take the letter to West Tasman Drive, and then refer to the street address and deliver it to 170. When the letter is actually on Cisco premises, the employee name would be used to forward it to its ultimate destination.

Referring only to the relevant address level (country, state, city, street, number, and employee) at each stage when directing the letter onto the next hop makes this process very efficient. There is no need for each forwarding stage to know the exact location of the destination; the letter was directed in the general direction until the employee's name was finally used at the destination.

Hierarchical Network layer addresses work in much the same way. Layer 3 addresses supply the network portion of the address. Routers forward packets between networks by referring only to the part of the Network layer address that is required to direct the packet toward the destination network. By the time the packet arrives at the destination host network, the whole destination address of the host will have been used to deliver the packet.

If a large network needs to be divided into smaller networks, additional layers of addressing can be created. Using a hierarchical addressing scheme means that the higher levels of the address (similar to the country in the postal address) can be retained, with the middle level denoting the network addresses (state or city) and the lower level the individual hosts.