Courtly And Uncourtly Views Of Poetry :: essays research papers

Between the twelfth and fifteenth century, the form of the lyric was founded in and became very popular within England. Few of the lyrics that were composed remain in existance today. This is mainly due to the fact that these lyrics were transferred orally. This meant they were never printed or published. The ones we do have paint for us a vague but sufficient picture of life as it was in these times. Particularily they give us a peek into the lives of the women of the medieval era and how they were viewed by their patriarchal society. The ways women were portrayed in much of the poetry can be expressed in two broad categories: courtly and uncourtly. The former of these categories developed from the lyrics of the Provenà §-al troubadours. The latter is, in relation, a more modern view of women, one that sees them as irritating and stupid.   Ã‚  Ã‚  Ã‚  Ã‚  Courtly poetry, as I said, developed from the lyrics of the troubadours. Although there are many similarities, such as the woman’s high status, there are also many dissimilarities. One of the most obvious of these is these poets acceptance of the real world. It is difficult to find references to other women in the troubadours’ poetry let alone other relationships as one would find in the Middle English courtly lyric. An example of such a reference can be found in the refrain: â€Å"An handy hap ich habbe ihent! / Ichot from hevene it is me sent; / From alle wimmen my love is lent, / And light on Alisoun†(Luria, 27). This poet tells his lady that his heart is set on her and no other woman can pull him away. To a troubadour saying that there was anything but his lady would be abominable. There is little of the intensity of devotion and the analysis of love that is characteristic of the Troubadours. Nor are these personal lyrics of private, intimate love. On the contrary, they are public poems operating through well-recognized conventions. These conventions are a little different from those of the troubadours as well. The lady has hair of gold, a long neck, a slender waist and is often described as being prudent and wise. But these poems focus not on the lady but on the lover and his suffering for derne love or secret love. The lover’s day is spent sighing and begging his lady to pity and have mercy on him.

To What Extent is the Proposed Scottish Split from British Rule Benefic

To what extent is the proposed Scottish split from British Rule beneficial for either country? The economical bond between England and Scotland has stood since the Acts of Union in 1707. Years of undivided companionship have convinced the majority of the world that there are no borders separating the U.K countries. This, it seems, has taken its toll on the Scottish Government. As after centuries of companionship they have decided to follow Ireland’s example and propose independence. Whether or not this was a wise move by the Scottish National Party leader, Alex Salmond, is up for debate. The true extent of pros and cons, although they will vary depending on public viewpoints, will be uncovered on the 18th September 2014 at the final vote count. The benefits of the proposed split, on Scotland’s side, are outweighed by the troubles that will be brought by attempting to enter the EU, the Economy and National Debt. If independence is granted, the UK will exit the split with no significant change while Scotland will face immense struggles. The most compelling argument against independence, from an economic view, is the problem of the Euro. There is an abundance of current turmoil in several countries, where leaders are facing similar independence issues to the UK. Several international leaders, facing devolution movements, are openly hostile towards the Scottish Referendum. Those in the EU are particularly dismissive. EU rules state that those who wish to join must adopt the Euro. Britain and Denmark have exclusive permission from Brussels, which is considered to be the de facto capital of the European Union, to use independent currency. The fact that Scottish National Party (current government in power) wishes to keep the pound... ...oil reserves will not only abandon the UK but according to Shell’s statement Scotland will be stranded as well. It’s clear through simply glancing at the facts that if the SNP emerges from this Referendum triumphant, they will be economically stranded in Europe. However this will only occur if the Referendum swings in the SNP’s favour. The reason behind Scotland’s proposed struggle is the economies of the remaining UK countries and Scotland being linked for centuries. Breaking this would leave both participants is considerable distress. But the remaining UK members, due to their combined populations and stronger trade partners, will emerge in a much better position. The true result will only become apparent if the SNP wins the September Referendum. The likelihood of SNP triumph is unclear as of yet, however according to current polls the ‘No’ vote is favoured.

Advantages and Disadvantages of Living in Before Marriage

Today, many couples choose living in before marriage because they believe it will let them know if they are suited for marriage. Living in before marriage has some advantages and disadvantages for the couple and some of those are listed below. Some of the advantages of living in before marriage are: living-together Living together will lower the cost of food, rent and bills because two people are splitting the cost of living. In some cases, one person takes care of all the bills.In those cases, it is usually the woman who gets the benefit of free room and board costs. Having someone there for emotional support, sexual relations and for conversation without being committed in a marriage is considered an advantage for most couples. Living together before marriage allows the couple to test their compatibility. For some people, they want to feel that they can get along with someone while living together before they plan for their wedding. By living together, you will see how loyal your p artner is to you.This will help you build trust together that cannot be shaken if you agree to get married in the future. By living together, you can prepare for marriage ahead by learning someone’s habits, attitudes and manners. There are also some disadvantages of living together before marriage. These are: living-together2 By living together for a long time, you may get too comfortable with each other and totally avoid tying the knot in the future. Living together makes it easier for one partner to walk out on the relationship because there is no legal obligation to the other person.Living together can encourage an easy out for someone who wants it. Living together is often short-lived, statistics has shown. The female is the one who usually suffers if the relationship does not work out. Women tend to feel that they lose time, because of their biological clock, and dignity when they live together with a partner that ends in a break-up. No one knows for sure that living tog ether before marriage is the best thing to do. It is much easier to walk out of a relationship than it is walk out of a marriage.Everyone knows that divorce involves a lot more than what a break-up involves for a couple just living together. Many pastors and marriage counselors advise young couples that if they believe in the institution of marriage to find someone who believes in that themselves. People who believe in the sanctity of marriage do not suggest living with someone first just to get to know them better or see if they are well-suited for each other. After all, marriage is an institution, and we cannot learn things outside of an institution.

TOK wok

TOK Writing Assignment â€Å"When the only tool you have is a hammer, all problems begin to resemble nails. † (Abraham Maslow) How might this apply to ways of knowing, as tools, in the pursuit of knowledge? Ways of knowing embody memory, language, emotion, intuition, sense perception, reason, imagination, and faith, which take part in the process of acquiring knowledge. For instance, language can be considered as a means of exchanging the knowledge with each other and emotion is a way to express our personal feelings and convey the message to other people.We are able to use hese ways of knowing as a tool to obtain knowledge, therefore understanding the world around us. Speaking of tool, the quote above might suggests that if we only have a hammer, thus it becomes the only way to solve all the problems, which means all the problems are naturally seemed as nails in our mind, even if they are essentially not. In this case, the hammer impacts the viewpoint towards all the problems . That being said, we are likely to determine the things around us, even the world, based on the tool we are holding.This concept provides an idea that if ways of nowing is conceived as a tool, like a hammer, it will affect how we evaluate the problem first, consequently impacting the way we solve the problems and even shaping the way in which we think about the world around us. Sense perception, one way of knowing, is defined as a mechanism by how we obtain knowledge on stimulation of senses. In simple terms, we use senses to look and feel, in order to understand the world.Seeing and hearing are two common materials contributing to sense perception, which play a significant role in impacting how we think about the world. An example of it happened to me, which made me strongly feel the power of sense perception on the view towards the world. Since now I am studying in Canada, a multi-culture country, my friends at school are from all over the world, who have different skin and hair color. It is easy to see people of different nationalities, while I am walking on the street.In stark contrast, it is rare to find people with different hair color in the country where I come from, especially the time when my great grandmother grew up. By chance, I showed my great grandmother the photos of my riends here; she was totally shocked by all kinds of different hair color she saw. She sat stunned for a while and said, â€Å"Oh, how come they don't have black hair! They look completely different from us. Unbelievable, can't imagine, that's not true†¦ This is the first time, my great grandmother actually saw people in different hair color and she was shocked by that, even doubted herself at the first few seconds. It is because she thought that everyone in the world had black hair and yellow skin, more interestingly, she has never even thought about other countries in her realm of knowledge. However, for a ninety-eight-year-old person in China, what she saw every day we re people with black hair and everything she heard was about the xanthoderm. It is not surprising that she naturally had this viewpoint of the world according to what she saw and heard.This simple example demonstrates the idea that sense perception, as a way of knowing, has the ability to influence how we look the problem, in this case, the world, and then drawing a conclusion of the problem. Not only the sense perception as a way ot knowing can steer the pursuit ot knowledge, faith also shows its strong effect on it. With regard to faith, it reminds me of a poem I read in my English class. The poem â€Å"Limbo†, wrote by Seamus Heaney, portrays a depressive story that a Catholic mother attempted to kill her baby by putting him in the sea in 1970s.The reason why she did that is because this is an illegitimate infant and she thinks it is the right thing to do based on her strong Catholic faith. In comparison to the Buddhism, they would never put it in the same way, because kil ling a baby regardless of if the baby is an illegitimate or not can be considered as a sin according to their faith. Catholicism and Buddhism both believe in different faith, which leads two completely opposite Judgments towards the same thing.In other words, different faiths allow people to Judge differently as they look from the different angles towards one thing, in the second place, leading to make different decisions. Simply put, the concept that ways of knowing could shape the way we estimate problems and coming up with different ways to solve them is verified by this example. Nevertheless, there is a common counterclaim states that the way we solve a problem is based on the problem itself, furthermore how we look t the problems does not change the essential meaning or property of the problems.Although it might be true, during the process of estimating a problem and solving it, we unconsciously interpret the problems in our own unique way. Hence when we convey those problems o r ideas to other people by languages, what they acquire is the personal viewpoint towards those problems, not the problem itself, which means we indirectly change the property of the problems when we deliver them by using the tool we has. This implicates language, another way of knowing, is able to shape ow we look and interpret things around us.As a foreign student, English is my second language which I am using as a tool to exchange ideas with other people now. I always find that it is really hard for me to translate Chinese directly into English, vice versa. It is because the way we compose a sentence, the structure of the sentence and the order of the sentence constituents are all different. For instance, when we describe an object, we chronically put all the adjectives in front of the object; however, English-speakers prefer to describe an object following with a subordinate lause, which means the important part of the object is actually appearing after it.As I have been speaki ng mandarin for almost sixteen years, an entrenched idea exerts a great impact on me as I unconsciously value the things with the description in front of them more than those having the description after them at the time I see or hear them. Since I habitually pay more attention to that, I would somehow miss the part where my Canadian friends are trying to emphasize by using the way they describe a thing, which leads to misunderstandings or estimating things differently.However, ccording to my situation now, living in an English-speaking country, I should drop my mandarin hammer and pick up the English hammer, in order to nail the right thing with the right tool. All in all, the idea that ways of knowing have the ability to impact how we formulate ideas, derive conclusions, and thus gaining knowledge has been demonstrated by exploring different ways of knowing such as sense perception, faith, and language. Throughout my essay, we are able to conclude we use different ways of knowing as tools to seek the treasure of knowledge and allowing these tools to decide what (1243) kind ot treasure we are going to tind

Greek Tragedy Essay

Art and literature has existed throughout time to represent and express cultural values, ideals and perceptions. It often portrays the forces that push one’s particular culture onward, mentally stimulating and expanding individual mind and thought. In ancient Greek culture, Art and Literature is combined in a way that represented all of these things to its people. This combination is what we know as ancient Greek Theater, an art of drama and song, with the structure of â€Å"spoken portions interlaced with choral lyrics, all concerned with man’s fate. â€Å"1 Greek tragedy is credited to have developed around 534 B. C when the Greek Thespis created drama in which a main actor conversed with the leader of the chorus (this is where the term â€Å"thespian† originated, it has been used to describe an actor since the early 19th century). 2 Aeschylus, the first of the great 3 tragic poets, added a second actor to his plays and had a chorus of around 12. Sophocles, the second of the great poets, added the third actor and increased the chorus to 15 members. Sophocles is considered to model Greek tragedy, with Aeschylus marking the preparation and Eudripidies the decline. 3 These plays where preformed at Festivals in open-air theaters in which poets competed for prizes. It is widely accepted that these festivals where religious, and honored the Greek god Dionysius (God of Wine). All plays where developed around well-known ancient Greek myth, it was the Poets job to develop character and deepen plot. Each festival included 3 tragic poets to present a â€Å"tetrology. â€Å"(A group of 4 plays) which consisted of 3 tragedies and one satyr. 4 Each play would include anywhere from two to four actors, and an assembly of 12-15 choral members. It was each actor’s responsibility to display the plot through speech, however they where also responsible for singing solos. The chorus was an important tool in Greek tragedy as they commented on each scene and proposed subtleties to the audience, their song also heightened the emotion and atmosphere of the play. 5 Aristotle’s â€Å"Poetics† is considered the most valuable source of guidance for Greek tragedy. Aristotle defines tragedy as † a drama which concerned better than average people (hero’s, kings, gods) who suffer a transition from good fortune to bad fortune and who speak in an elevated language. † 6 It is also defined as † a literary composition written to be preformed by actors in which a central character, called the tragic protagonist or hero, suffers some serious misfortune which is significant in that the misfortune is logically connected with the hero’s actions. â€Å"7 The hero is often host to some â€Å"tragic flaw† (hermatia) for which he himself is responsible, and which leads to his eventual downfall. However, Aristotle describes this tragic flaw to lead to a mistake in which the Protagonist is not aware. The hero’s destruction is often due to his self-ignorance. It is important to understand what Aristotle believes is the purpose for Greek tragedy in order to completely understand some of its main aspects. In Aristotle’s opinion, one of the marks of great tragedy is its ability to create a Cartharsis, the act of purging the soul of â€Å"fear and pity. â€Å"8 Through creating a complex protagonist, a character who is seen as a great man, or â€Å"hero†, the audience in turn creates respect. Through this character’s tragic flaw, and ignorance to his actions, the audience is drawn and starts to pitty the hero. The audience imagines themselves in the hero’s situation, and although they know the outcome of the story (as all Greek tragedy is bases on well-known Greek myth) they suspensefuly await the hero’s reaction to his fate. So this â€Å"purging† allows the audience to shed excess fear, refreshing their conscience so that it can exist in a healthy balance. Aristotle theorized that â€Å"tragedy is rooted in the fundamental order of the universe. â€Å"9 Tragedy is a worse case scenario, which describes the possible effects of simple probability. It creates a â€Å"cause-and-effect chain† in which any individual can envision themselves as part of. We can now understand the importance of certain aspects of the tragic hero’s character and his responsibility to uphold the plot. â€Å"A hero, in the Greek sense, is a man who by his extraordinary career has pushed back the horizons of what is possible for humanity and is then deemed worthy of commendation after his death. â€Å"10 As we know, this hero is not flawless. However, it is important to realise that in what Aristotle values as good tragedy, these flaws often contribute to the very virtues which allow our protagonist to become a hero in the first place. In other words, tragic irony is implicated, and it is the same incidents and qualities of a man which catapult him to hero stature as those which drag him down. Tragedy is concerned with the fate of â€Å"big men. â€Å"11 Aristotle believed that Sophocles’, â€Å"Oedipus Rex† was the perfect tragedy. Why was Oedipus Rex in effect the perfect tragic hero? Oedipus was a great man and King of Thebes. He was self righteous, hasty and suspicious of his friends, but we also see that if it where not for these qualities Oedipus would not have continued with his inquiries. His heroic nature is magnified in his persistence for the truth despite the fact that it became quite obvious that gaining further knowledge would end in disaster and self-destruction. 12 Peripeteia is when a character produces â€Å"an effect opposite to that which he intended to produce. † 13Aristotle firmly believed that all good tragedy proposed some peripeteia within its plot. This is perfectly represented within â€Å"Oedipus Rex. † Oedipus promises his people that he will find the root of the plague that gripped his kingdom. In ancient Greek times, it was believed that illness and plague where signs from the gods that they where upset or a crime against their godly standards had been committed. So as any noble hero would do, Oedipus sets out on a quest for this knowledge. He soon discovers that the murder of Thebe’s prior king, Laius, is the root off his city’s pollution. He vows to discover the murderer, and sets the punishment of death or banishment to whomever was found guilty. This was his intention. We can also see again that Oedipus is a noble hero, as he is a king and he is willing to go to any ends for his people. These traits would have invoked feelings of respect in the minds of the audience. As Oedipus discovers more information, he draws nearer to the conclusion that it is possible that through self-blindness and ignorance, Oedipus himself is the likely murderer of Laius. Through this step in the play we see that again Oedipus carries the qualities of a tragic hero; his murdering of Laius was due to his self-arrogance and lack of knowledge that the man who he was killing was of high status. This murder was indeed due to Oedipus’s tragic flaw of Hubris (‘arrogant disregard for the rights of others’, or â€Å"overbearing pride or presumption† 14) but he was unaware of the consequences and the murder was quite spontaneous. Oedipus continues to search for the truth despite his possible self-guilt, as he states that he must be sure that he is indeed Leuis’s murderer. This, according to human standards, Oedipus not only behaved well in this situation, but he is known to have â€Å"asserted the dignity of manhood. † Alas, more investigation does lead to his definite guilt, and also leads to what is known as an â€Å"Agagnorisis,† or a † change from ignorance to knowledge. â€Å"15 Oedipus had not been born heir to the throne of Thebes. After learning of a prophecy that he would one-day murder his father and marry his mother, he ran away from his ‘parents’ to escape this fate. He had arrived in Thebes just after the time of Laius’s death. A sphinx was afflicting the city at the time, and he defeated it, there-for winning the admiration of the Thebans and stealing the heart of newly widowed queen, Jocasta. Their marriage was nearly instant, and they lived in happiness for some years and produced a number of children. So it was at this â€Å"agagnorisis† when Oedipus learnt that he had been adopted, and that Laius had been his father, and Jocasta his mother. They had discarded him apon a hill after hearing the very same prophocy, hoping they too could escape their fate. This unraveling of the plot is called the â€Å"lusis. â€Å"16 This is where the Peripeteia is for filled. Although Oedipus had always intended to catch and punish the murderer of Leius, he in no way intended that it would be himself who was responsible. This is also ironic in the sense that twice he had unknowingly set the path for his own destruction. Another form of Greek tragedy is the decision that the tragic hero must face once he has reached his agagnorisis. 17 Oedipus had a choice, to continue to live in sin with his mother/wife and perpetuate the slow destruction of Thebes, or to uphold the little dignity he had left, finally accept his fate and finalize the promises he made to his people. Oedipus chooses to do what any hero would do, accept responsibility for his actions and punish himself as he promised to do in the beginning of the play. The knowledge of his sin against his father and mother causes him to blind himself, as he could not bear to look upon the world any longer. This fact again adds irony to the story, as when Oedipus was able to see physically, he was still blind to his past and the consequences of his actions. Through his blinding, he was self-knowing, and he had for the first time accepted his fate. He left Thebes as a blind beggar. Although in some respects Oedipus is now seen as no longer a hero, the audience would have respected his final decisions, and in some way he had corrected his moral flaw through his self-punishment. We can now question the belief of fate and pre-determination. Greek tragedy did indeed deal with the role of the gods in mortal life and to the extend that mortals controlled their actions. Oedipus was responsible for his deeds, as it was by no accident that Laius died, and Oedipus did have a tragic flaw, which led to this murder. But we can also examine the fact that a prophecy existed which laid out the steps that Oedipus would take through out his life. If it where not for Oedipus’s knowledge of this prophecy, would he have ever left his home in Corinth, would he have ever murdered Laius, and married his mother? Or we can look even further into Oedipus’s past; if Jocasta and Leius had not known of this prophecy, they would never had abandoned Oedipus, and perhaps he would never had committed the sins which it seems he was destined to commit. So again we see a cause and effect chain, knowledge leading to ignorance, ignorance in turn leading to knowledge, blindness to sight, sight to blindness. It is also argued that it was the individual’s attempt to escape their fate which was the true crime against the gods. It is at this point we can see how the Cultural Revolution, known as ‘The Greek Enlightenment’, effected these drama’s. It was from this new atmosphere of questioning and individualism in which man started to question the meaning of life beyond the restraints of ‘God rules man. ‘ And not only did Greek tragedy come to question the gods, it also questioned what it meant to be human. 18 1 The Complete Plays of Sophocles. 2 http://www. stemnet. nf. ca/~hblake/tragedy1. html 3 http://www. classics. cam. ac. uk/Faculty/tragedy. html 4 www.depthame. brooklyn. cuny. edu 5 15 Greek Plays 6 The Complete Plays of Sophocles 7 www. depthame. brooklyn. cuny. edu 8 9 www. cnr. edu/home/bmcmanus/poetics. html 10 The Complete Plays of Sophocles. 11 The Complete Plays of Sophocles 12 The Complete Plays of Sophocles 13 www. depthame. brooklyn. cuny. edu 12 American Heritage dictionary 15 www. cnr. edu/home/bmcmanus/poetics. html 16 www. cnr. edu/home/bmcmanus/poetics. html 17 http://www. stemnet. nf. ca/~hblake/tragedy1. html 18 http://www. stemnet. nf. ca/~hblake/tragedy1. html.

Address Resolution Protocol

————————————————- Address Resolution Protocol The  Address Resolution Protocol  (ARP) is a  computer networking  protocol for determining a network host's link layer or hardware address when only its  Internet Layer  (IP) or  Network Layer  address is known. This function is critical in local area networking as well as for routing internetworking traffic across gateways (routers) based on  IP addresses  when the next-hop router must be determined. ARP was defined by  RFC 826  in 1982. [1]  It is  Internet Standard  STD 37. ARP has been implemented in many types of networks, such as  Internet Protocol  (IP) network,  CHAOS,  DECNET, Xerox  PARC Universal Packet,  Token Ring,  FDDI,  IEEE 802. 11  and other  LAN  technologies, as well as the modern high capacity networks, such as  Asynchronous Transfer Mode  (ATM). Due to the overwhelming prevalence of  IPv4  and Ethernet in general networking, ARP is most frequently used to translate  IPv4 addresses  into Ethernet  MAC addresses. In the next generation Internet Protocol,  IPv6, ARP's functionality is provided by the  Neighbor Discovery Protocol  (NDP). ———————————————— Overview and IPv4-plus-Ethernet example Consider a LAN where machines using IPv4 over Ethernet wish to communicate. A sender wishes to send a message to some other machine on the LAN and knows a destination IPv4 address. The destination IPv4 address is hopefully associated with some appropriate network interface belonging to the recipient machine, and is present on the LAN. But in order for communication to succeed, the sending machine  first needs to discover the ethernet MAC address of the intended recipient network interface. This requirement comes about because Ethernet hardware does not (necessarily) understand IPv4 protocols or IPv4 addresses in the sense that Ethernet hardware ‘listens out for' relevant Ethernet MAC addresses but does not ‘listen out for' IPv4 addresses. (An impractical alternative would be to have all units listen to every Ethernet packet and inspect the contents for relevant IPv4 addresses, discarding the packets that are intended for other devices, but this would be very inefficient. ) So before sending an IPv4 packet, the sender sends a roadcast message onto the LAN using ARP in order to discover the Ethernet MAC address of some interface that is listening for that desired target IPv4 address. Some appropriate unit replies that it has a network interface with a certain MAC address that is associated with the IPv4 address in question. The original would-be sender now has the information needed and can go ahead and send its IPv4 packet to the destination inserting it int o an Ethernet frame with the correct destination MAC address for the appropriate recipient. The sender's operating system also stores the newly discovered MAC address in a table (‘caches' the result). This table of mappings from IPv4 addresses to MAC addresses is retained and consulted again and again, so the ARP discovery procedure only has to be performed one time, when a packet is sent to a ‘new' destination IPv4 address. ————————————————- Operating scope The Address Resolution Protocol is a low level request and answer protocol that is communicated on the media access level of the underlying network. For  Ethernet  systems, an ARP message is the payload of Ethernet packets. ARP therefore operates only across the local link that a host is connected to. Within the framework of the  Internet Protocol Suite, this characteristic makes ARP a  Link Layer  protocol. [2] ARP is also very often discussed in terms of the  Open Systems Interconnect  (OSI)  networking model, because that model addresses hardware-to-software interfaces more explicitly and is preferred by some equipment manufacturers. However, ARP was not developed based on the design principles and strict encapsulation hierarchy of this model and, therefore, such discussions create a number of conflicts as to the exact operating layer within this model. Most often ARP is placed into the  Data Link Layer  (Layer 2), but since it requires the definitions of network addresses of the  Network Layer, it is not unusual to find it referenced at that layer. An example of use in OSI networking, is ATMARP, used to resolve  Asynchronous Transfer Mode  (ATM)  NSAP  addresses in IP over ATM deployments. ————————————————- Packet structure The  Address Resolution Protocol  uses a simple message format that contains one address resolution request or response. The size of the ARP message depends on the upper layer and lower layer address sizes, which are given by the type of networking protocol (usually  IPv4) in use and the type of hardware or virtual link layer that the upper layer protocol is running on. The message header specifies these types, as well as the size of addresses of each. The message header is completed with the operation code for request (1) and reply (2). The payload of the packet consists of four addresses, the hardware and protocol address of the sender and receiver hosts. The principal packet structure of ARP packets is shown in the following table which illustrates the case of IPv4 networks running on Ethernet. In this scenario, the packet has 48-bit fields for the sender hardware address (SHA) and target hardware address (THA), and 32-bit fields for the corresponding sender and target protocol addresses (SPA and TPA). Thus, the ARP packet size in this case is 28 bytes. Hardware type (HTYPE) This field specifies the Link Layer protocol type. Example: Ethernet is 1. Protocol type (PTYPE) This field specifies the upper layer protocol for which the ARP request is intended. For example, Internet Protocol (IPv4) is encoded as 0x0800. Hardware length (HLEN) Length (in  octets) of a hardware address. Ethernet addresses size is 6. Protocol length (PLEN) Length (in octets) of a  logical address  of the specified protocol (cf. PTYPE). IPv4 address size is 4. Operation Specifies the operation that the sender is performing: 1 for request, 2 for reply. Sender hardware address (SHA) Hardware (MAC) address of the sender. Sender protocol address (SPA) Upper layer protocol address of the sender. Target hardware address (THA) Hardware address of the intended receiver. This field is ignored in requests. Target protocol address (TPA) Upper layer protocol address of the intended receiver. ARP protocol parameter values have been standardized and are maintained by  IANA Internet Protocol (IPv4) over Ethernet ARP packet| bit offset| 0 – 7| 8 – 15| 0| Hardware type (HTYPE)| 16| Protocol type (PTYPE)| 32| Hardware address length (HLEN)| Protocol address length (PLEN)| 48| Operation (OPER)| 64| Sender hardware address (SHA) (first 16 bits)| 80| (next 16 bits)| 96| (last 16 bits)| 112| Sender protocol address (SPA) (first 16 bits)| 128| (last 16 bits)| 144| Target hardware address (THA) (first 16 bits)| 160| (next 16 bits)| 76| (last 16 bits)| 192| Target protocol address (TPA) (first 16 bits)| 208| (last 16 bits)| ————————————————- ARP probe An  ARP probe  is an ARP request constructed with an all-zero  sender IP address. The term is used in the  IPv4 Addre ss Conflict Detection  specification (RFC 5227). Before beginning to use an IPv4 address (whether received from manual configuration, DHCP, or some other means), a host implementing this specification must test to see if the address is already in use, by broadcasting ARP probe packets. ————————————————- ARP announcements ARP may also be used as a simple announcement protocol. This is useful for updating other host's mapping of a hardware address when the sender's IP address or MAC address has changed. Such an announcement, also called a  gratuitous ARP  message, is usually broadcast as an ARP request containing the sender's protocol address (SPA) in the target field (TPA=SPA), with the target hardware address (THA) set to zero. An alternative is to broadcast an ARP reply with the sender's hardware and protocol addresses (SHA and SPA) duplicated in the target fields (TPA=SPA, THA=SHA). An ARP announcement is not intended to solicit a reply; instead it updates any cached entries in the ARP tables of other hosts that receive the packet. The operation code may indicate a request or a reply because the ARP standard specifies that the opcode is only processed after the ARP table has been updated from the address fields. [4][5][6] Many operating systems perform gratuitous ARP during startup. That helps to resolve problems which would otherwise occur if, for example, a network card was recently changed (changing the IP-address-to-MAC-address mapping) and other hosts still have the old mapping in their ARP caches. Gratuitous ARP is also used by some interface drivers to effect load balancing for incoming traffic. In a team of network cards, it is used to announce a different MAC address within the team that should receive incoming packets. ARP announcements can be used to defend  link-local  IP addresses in the  Zeroconf  protocol (RFC 3927), and for IP address takeover within  high-availability clusters. ————————————————- ARP mediation ARP mediation  refers to the process of resolving Layer 2 addresses when different resolution protocols are used on multiple connected circuits, e. . , ATM on one end and Ethernet on the others. ————————————————- Inverse ARP and Reverse ARP The  Inverse Address Resolution Protocol  (Inverse ARP or InARP), is a protocol used f or obtaining  Network Layer  addresses (e. g. ,  IP addresses) of other nodes from  Data Link Layer(Layer 2) addresses. It is primarily used in  Frame Relay  (DLCI) and ATM networks, in which Layer 2 addresses of  virtual circuits  are sometimes obtained from Layer 2 signaling, and the corresponding Layer 3 addresses must be available before these virtual circuits can be used. As ARP translates Layer 3 addresses to Layer 2 addresses, InARP may be described as its inverse. In addition, InARP is actually implemented as a protocol extension to ARP. It uses the same packet format from ARP; but has different operation codes. Reverse Address Resolution Protocol  (Reverse ARP or RARP), like InARP, also translates Layer 2 addresses to Layer 3 addresses. However, while in InARP the requesting station is querying the Layer 3 address of another node, RARP is used to obtain the Layer 3 address of the requesting station itself for address configuration purposes. RARP is now obsolete. It was replaced by  BOOTP, which was later superseded by the  Dynamic Host Configuration Protocol  (DHCP). ————————————————- Proxy ARP Proxy ARP  (Address Resolution Protocol) is a technique by which a device on a given network answers the  ARP  queries for a  network address  that is not on that network. The ARP Proxy is aware of the location of the traffic's destination, and offers its own MAC address in reply, effectively saying, â€Å"send it to me, and I'll get it to where it needs to go. Serving as an ARP Proxy for another host effectively directs LAN traffic to the Proxy. The â€Å"captured† traffic is then typically routed by the Proxy to the intended destination via another interface or via a  tunnel. The process which results in the node responding with its own MAC address to an ARP request for a different IP address for proxying purposes is sometimes referred to as ‘publishing'. ————————————————- Uses Below are some typical uses for proxy ARP: Joining a broadcast LAN with  serial  links (e. g. ,  dialup  or  VPN  connections). Assume an Ethernet broadcast domain (e. g. , a group of stations connected to the same hub) using a certain IPv4 address range (e. g. , 192. 168. 0. 0/24, where 192. 168. 0. 1 – 192. 168. 0. 127 are assigned to wired nodes). One or more of the nodes is an  access router  accepting dialup or VPN connections. The access router gives the dial-up nodes IP addressses in the range 192. 168. 0. 128 – 192. 168. 0. 254; for this example, assume a dial-up node gets IP address 192. 168. 0. 254. The access router uses Proxy ARP to make the dial-up node present in the subnet without being wired into the Ethernet: he access server ‘publishes' its own MAC address for 192. 168. 0. 254. Now, when another node wired into the Ethernet wants to talk to the dial-up node, it will ask on the network for the MAC address of 192. 168. 0. 254 and find the access server's MAC address. It will therefore send its IP packets to the access server, and the access server will know to pass them on to the particular dial-up node. All dial-up nodes therefore appear to the wired Ethernet nodes as if they are wired into the same Ethernet subnet. Taking multiple addresses from a LAN Assume a station (e. g. , a server) with an interface (10. 0. 0. 2) connected to a network (10. 0. 0. 0/24). Certain applications may require multiple IP addresses on the server. Provided the addresses have to be from the 10. 0. 0. 0/24 range, the way the problem is solved is through Proxy ARP. Additional addresses (say, 10. 0. 0. 230-10. 0. 0. 240) are  aliased  to the  loopbackinterface of the server (or assigned to special interfaces, the latter typically being the case with  VMware/UML/jails/vservers/other virtual server environments) and ‘published' on the 10. . 0. 2 interface (although many operating systems allow direct allocation of multiple addresses to one interface, thus eliminating the need for such tricks). On a firewall In this scenario a firewall can be configured with a single IP address. One simple example of a use for this would be placing a firewall in front of a single host or group of hosts on a subnet. Example- A network (10. 0. 0. 0/8) has a serve r which should be protected (10. 0. 0. 20) a proxy-arp firewall can be placed in front of the server. In this way the server is put behind a firewall without making any changes to the network at all. Mobile-IP In case of  Mobile-IP  the Home Agent uses Proxy ARP in order to receive messages on behalf of the Mobile Node, so that it can forward the appropriate message to the actual mobile node's address (Care Of Address). Transparent subnet gatewaying A setup that involves two physical segments sharing the same IP subnet and connected together via a  router. This use is documented in  RFC 1027 ————————————————- Advantages The advantage of Proxy ARP over other networking schemes is simplicity. A network can be extended using this technique without the knowledge of the upstream router. For example, suppose a host, say A, wants to contact another host B, where B is on a different subnet/broadcast domain than A. For this, host A will send an  ARP  request with a Destination IP address of B in its ARP packet. The multi-homed router which is connected to both the subnets, responds to host A's request with its MAC address instead of host B's actual  MAC  address, thus proxying for host B. In the due course of time, when host A sends a packet to the router which is actually destined to host B, the router just forwards the packet to host B. The communication between host A and B is totally unaware of the router proxying for each other. ————————————————- Disadvantages Disadvantage of Proxy ARP include scalability (ARP resolution is required for every device routed in this manner) and reliability (no fallback mechanism is present, and masquerading can be confusing in some environments). It should be noted that ARP manipulation techniques, however, are the basis for protocols providing  redundancy  on broadcast networks (e. g. ,Ethernet), most notably  CARP  and  Virtual Router Redundancy Protocol. Proxy ARP can create DoS attacks on networks if misconfigured. For example a misconfigured router with proxy ARP has the ability to receive packets destined for other hosts (as it gives its own MAC address in response to ARP requests for other hosts/routers), but may not have the ability to correctly forward these packets on to their final destination, thus blackholing the traffic.

Alexander the Great

Alexander the Great Essay Alexander was born in July 356 B.C. to Philip II and his third wife, Olympias. The parents were far from a happy couple, and Alexander was raised primarily under the influence of his mother. At the age of thirteen, he was sent to study with Aristotlean education that was for the most part formal. Aristotle promoted the belief that non-Greeks were naturally slaves, thus encouraging the princes thirst for conquest. Ultimately, however, Alexander would reject this belief, at least implicitly, as he attempted to cooperate with the Persians even as he subjugated them. Returning to Macedonia after three years, Alexander soon had the opportunity to prove his strength in battle, as he subdued rebellions and contributed to his fathers famous victory over Athens and Thebes at Chaeronea. But when Philip divorced Olympias and married Cleopatra, Alexander began to fear that his father was looking for a new heir, and the father and son had a falling out. Their dispute was shortly resolved, but both remained suspicious of the other. Indeed, Philip was soon assassinated by a guard who presumably had a personal grievance, though Alexander and his mother are traditionally thought to have played some kind of role in Philips death. Alexander thus succeeded to the throne and began the inevitable dynastic purging of enemies. At the same time, he had to force the other Greek city-states to acknowledge his authority as Hegemon of the Hellenic League, which Philip had established. In doing so, Alexander razed the city of Thebes as an examplethough many sympathized w ith Thebes and only grew to resent Alexander more deeply. But Alexander had more important concernsnamely, the Persian expedition. This had been Philips dream and Alexanders inheritance, and he wasted no time in beginning. Alexander advanced gradually and conquered territory by territory until Darius, the Great King of Persia, was forced to come out himself to face Alexander. Alexander was victorious in the two key battles at Issus and Gaugamela, and Darius was murdered by conspirators soon afterward. In the meantime, Alexander also conquered Phoenicia, Egypt, and Babylon, all of which proved to be valuable acquisitions. Upon hearing of Dariuss death, the Macedonian army assumed that the expedition was over and the war won, but Alexander insisted on pushing farther east. Here he faced a formidable opponent in Spitamenes, who possessed a smaller army but continued harassing Alexander and even slaughtered a Macedonian unit after Alexander underestimated him. Spitamenes was ultimately defeated, the rebellion fell apart, and Alexander went on to conquer the Paraetacene territory. In the Far East, Alexander founded a large number of cities that would contribute to the expansion of Greek culture. Finally there remained India (which at the time referred to a small area in western Pakistan, not the country of modern times). Although Alexander was already the undisputed king of Asia, he would not be satisfied until he had personally vanquished the entire continent. He soon allied himself with one ruler, Ambhi, but there remained Ambhis enemy Porus. The result was one of Alexanders greatest military achievements, but the battle was difficult, particularly because the Macedonian army had had to face a frightful experience in fighting elephants. After India, Alexander wanted to press still farther, recognizing that Asia extended beyond what he may have expected from limited geographical knowledge. At this point, however, his troops finally refused to further, and mutinous thoughts stirred after eight hard years of combat and marching. Alexander was furious, but he was eventually forced to give in and return home. Back in Persia Alexander dealt with administrative matters, including the replacement of various satraps, or local rulers. More important, his experience of Asia had changed his attitude toward Persians. His desire to cooperate with the Persians alienated many conservative Macedonians, who still viewed Persians as barbarians. Alexanders new attitude may even have led to his death in 323 B.C. READ: Human face portrait Essay Though the official cause of his death was a fever aggravated by heavy drinking, many historians have speculated that Alexander was poisoned by Aristotle, his former tutor, and Antipater, his close advisor, as a result of his favorable treatment of the barbarians. .