Hi there kids, welcome to networking club. Here are the rules:
- Don’t talk about fight club.
Annnnd that’s it. Ok, let’s get started then. So you realized you don’t know how dem old internet tube highways things actually work, and you thought you would get some learnings. You have come to the right place.
This post assumes you know basic things about IP addresses. If you don’t, well, this is going to be confusing.
In this first lesson, I want to start simple. I just want to explain what actually happens when two computers on the same network send each other messages.
Suppose I have two computers, A and B.
A: 192.168.0.10
B: 192.168.0.11
Make sure you take note of these numbers closely, because as it turns out I never actually reference these numbers later on and they are useless. Got it? Great.
Let’s suppose A and B are connected to the same switch, and nothing else is connected to the switch. When A sends a packet to B, what happens?
WRONG! Oh, you didn’t actually answer? Well… you are still wrong. Here is what happens:
It sends the packet. Duh. You should know that part already.
But as it turns out, it isn’t actually that simple. There is a hidden layer underneath that you probably haven’t touched before.
Layers
When computer A wants to send a packet to computer B, it first must check its ARP cache for computer B’s IP address.
ARP cache? What de heck is an ARP cache?
I was just getting to that. So, the first thing most people learn about computers networks is that all computers have an IP address, and that is how they send packets to each other.
Now as it turns out, there are multiple layers of protocols. And, because humans are so creative, we gave each of them a number. Layer 1, the lowest level, is basically just the electrical part, where all the fancy bits go in the fancy cable and woop de do they end up on the other side. I don’t know how any of that stuff works, so let’s skip that.
After layer 1 is… dun dun dun… layer 2. Layer 2 is technically called the data link layer, or something fancy like that, but practically speaking it is just the “Ethernet protocol.” Layer 2 actually has its own type of addresses: MAC addresses. You may have encountered these before. They look like this:
2A-51-1F-2A-F9-DE
Anything that has an IP address also has a MAC address. If you run ipconfig /all on windows, it is listed as the Physical Address for a given interface.
After layer 2, naturally, is layer 3. Layer 3 is the network layer. You can think of it as the IP layer. So you have layer 2 addresses – MAC addresses – and you have layer 3 addresses – IP addresses. Every packet on the network has a layer 2 and layer 3 component.
The layer 3 part is contained inside the layer 2 part. If you read a networking textbook, they have fancy diagrams explaining this concept, which is called encapsulation. But we aren’t fancy here, so I will make it simple. Let’s say you have a box. Then, because you do like boxes so good, you put that box in a bigger box. Oh, and also, you wrapped both of them in wrapping paper, because it is shiny.
In other words, you encapsulated a box inside another box. Now, suppose somebody sent you a similar box, which has an outer box and an inner box. And maybe you think of yourself as an outer box guy, and your friend is the inner box guy. So the outer box comes to you, you unwrap it, then you pass the inner box to your friend, who then opens it and finds what is on the inside. In this example, you, the outer box guy, are acting as layer 2. Your friend is layer 3.
Let’s use another example. Suppose you went to google.com. Let’s say that is the innermost contents of the box. Then, you wrap that up in a box that has google’s IP address on it, so it ends up in the right place. That is, you put on the layer 3 wrapping. Then, you put that box in another box, and label that outer box with the MAC address of your destination – this is the layer 2 wrapping. You feel very accomplished, and send your box to the destination.
When your box arrives at the destination, this entire process happens in reverse. When you sent the box, you had the packet contents (google.com, for example – we can call this the application layer), then the network layer was added onto it, and then the data link/ethernet layer – layer 2 – was added onto that. So, when the destination end unwraps the box, they first see layer 2, and then layer 3, and then inside it all is whatever you sent to google.com.
Earlier, when I said I wasn’t fancy? I lied. I am super fancy, and I made this picture with a bunch of rectangles just for you. As you can see, when Computer A sends a packet, it starts at the highest layer – in this case, transport – and makes its way down the green arrow path, adding more and more layer wrappings, until it reaches the physical layer. There are also a bunch of turtles below there – turtles all the way down, as it turns out – but we can ignore those.
So the packet goes down to the physical layer. It then goes across the network in a cable, or perhaps calls for a cab. Then, it reaches the other computer at the physical layer, and works its way all the way up to the transport layer on the other side, shedding layers as it goes up.
When computer B sends a reply packet, that entire process happens in reverse. The packet goes down the stack on computer B, adding each successive layer, and it then is transmitted on the physical layer. Upon reaching computer A, each layer is peeled back, and the inner box is passed up to its respective layer.
As indicated by the fancy black lines in the middle, each layer, in a way, only communicates with its direct neighbor. Generally speaking, no protocol knows anything about the layer above it, and for the most part doesn’t care what is below it.
For common TCP/IP networks, Layer 2 is Ethernet, Layer 3 is IP, and Layer 4 is TCP (or UDP).
The “box” at each layer in this diagram, and the data it contains, has a specific name. There is a generic name, Protocol Data Unit (PDU), that is often used for the higher layers. But the lower layers have special names because they are referenced often. The outermost box with layer 2 information is called a frame. The inner box, with layer 3 information, is called a packet. They basically mean the same thing, but reference which step/layer we are looking at.
So that explains what layers are. The remaining question is, what is the ARP cache, and why is it needed to sent packets?
ARP
ARP is Address Resolution Protocol. It is used to map IP addresses to MAC addresses, and vice versa.
When computer A wants to send a packet to computer B, it has to prepare the boxes – layers – we mentioned before, so it can be “shipped” across the network. In this case, that means we need a layer 3 box as well as a layer 2 box. So computer A not only needs the IP address of computer B, which we already have (layer 3), but also the MAC address of computer B (layer 2). We cannot send computer B a packet (box) until we get its MAC address. This is where ARP comes in.
As I mentioned, everything with an IP address also has a MAC address. But how do you know which IP address corresponds with which MAC address, and vice versa? ARP to the rescue!
ARP is a layer 2 protocol. Most protocols you use, like HTTP (websites), are pretty high on the protocol stack (network layer stack), involving at least four layers of network protocols. But some protocols only exist at lower levels of the protocol stack, and ARP is one of them. So ARP, being at layer 2, exists below the IP layer (layer 3).
That means that when we send boxes for ARP, they only contain layer 2 stuff, not layer 3 stuff. It would be like if sending mail to somebody in the same city didn’t require a zip code. Because the path between the sender and recipient is simple (two computers on the same local network), less information (layer 3 box) is needed to get the box from A to B. So, ARP messages only need to be wrapped in a frame and not a packet.
Also, with Ethernet (layer 2), there is a special MAC address used for broadcasts, FF-FF-FF-FF-FF-FF. That’s a lot of F’s, my friends.
When we send layer 2 frames – just like packets, but at layer 2 – to this broadcast address, they actually go to every computer on our layer 2 network. This basically means every computer in your house.
So when your computer is trying to find the MAC address of another computer it has the IP of, it sends out an ARP discovery message to the entire network, asking “Who is using IP 192.168.0.11? Please respond to me, I am so lonely.”
Because that is sent to the broadcast MAC address, all computers on your network get it. One of the computer that gets it is computer B. Computer B looks at it and says “hm… I think that is my IP”, and having realized that, it replies to computer A and says “sup”.
When computer A sent the broadcast message, the source MAC address was also included – like a return mailing address. So when computer B received the message, it also received the MAC address of computer A, which allows it to send an answer directly back to computer A. The answer computer B sends to computer B is basically “I am using that IP address.”
And once A receives that frame from computer B, it looks at the source MAC address, and it now has the MAC address associated with that IP. Computer A has learned the MAC address of computer B.
So in the bigger picture, computer A wanted to send something to computer B. But it cannot do that until it finds computer B’s MAC address, so it sends out an ARP message. Computer B responds to that message. Now computer A, armed with computer B’s IP and MAC address, has all the information required to send a packet (and frame) over the network.
So that is what ARP is. That just leaves the cache part.
Packets get sent all the time on most networks. If computers had to send ARP requests every single time they sent a packet, it would double the traffic on the network, which is no good. So instead of doing that, computers remember MAC addresses they have learned through ARP in the ARP cache. In windows you can view this with the arp -a command, which shows (a)ll entries your computer has learned.
This is just like DNS caching. Entries in the ARP cache are only stored for a bit – as short as a minute – before they “fall out” of the cache and an ARP request has to be performed again. The reason for this is that if a computer’s IP address changes and a different computer gets that same IP address, then traffic intended for the first computer would end up going to the second since the ARP cache stores things by IP address. So it is stored long enough to prevent needing to send ARP packets all the time, but also refreshed often enough to not cause connectivity problems.
Conclusion
What did we learn today?
Um… a^2 + b^2 = c^2?
Kids these days….
In theory, you learned two things. First, computer networking involves layers of protocols, and layer 3 is the network (IP) layer and layer 2 is the data link (Ethernet/MAC address) layer. Every packet on the network contains both of these things.
Second, ARP is the protocol which binds these two layers together, by enabling computers to find MAC addresses based on an IP address.
Understanding that networking works in layers might not seem important at first, but as it turns out, most higher-level networking is just adding more layers on, and understanding how these layers interact with each other and what each layer does makes it much easier to troubleshoot when things go wrong.
Europe, and in Ancient Russia
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Deepika Padukone and Christy Turlington star in landmark Sabyasachi fashion show
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Camera phones at the ready, around 700 guests hailing from across India and the world expected a visual spectacle on Saturday evening — and they weren’t disappointed. A hush descended as the doors opened to the Jio World Center in Mumbai, where legendary Indian fashion designer Sabyasachi Mukherjee presented a star-studded 25th anniversary runway show for his namesake brand.
The celebrated designer — known for his maximalist Indian style — has dressed some of the biggest names across Bollywood and Hollywood, including Priyanka Chopra, Deepika Padukone, Oprah Winfrey, Rihanna and Jennifer Lopez. For his landmark show, the stars showed up to lend their support: Padukone opened proceedings in an all-white ensemble adorned with necklaces, including a crucifix from Mukherjee’s jewelry line. She later walked again with supermodel Christy Turlington as part of the grand finale.
Over 150 looks were presented, including pants and skirts embroidered with gold threads, frilled head gear, stacked jewelry and tops with slogans such as “cat lady,” “table for one,” “where has love gone,” and “all dressed up nowhere to go.” Mukherjee explained in a phone interview that these pieces were intended to be satire on how technology is dehumanizing humans. “We seem to have forgotten how to establish human relationships,” he said.
There were also trench coats, sweaters, shorts and shirts made in more conventionally western silhouettes. These marked a departure from Mukherjee’s usual festive and bridal wear, which are heavily inclined towards traditional Indian styles, such as saris, ghagra cholis and sherwanis.
But with no shortage of drama, the new collection featured heavily embroidered jackets embellished with semi-precious stones, brocade dresses, ostrich leather jackets and skirts, and blouses with velvet appliques overlaid with faux fur.
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‘I’m very impulsive’: Why this American woman moved to France at the age of 70
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She’d dreamed of living in France for years, but according to Janice Deerwester, originally from Texas, life always seemed to get in the way.
In 2021, Janice, who has been a widow since 2012, found herself lying on her bed with the lyrics to “Is That All There Is?,” a song about dissatisfaction that was a hit for country singer Peggy Lee back in 1969, playing in her head.
“I hated that song when it came out, but all of a sudden it came to my mind,” Janice, who was based in Georgia at the time, tells CNN Travel. “I thought, ‘Is this all there is?’ I work, come home tired. I get up. Is this it?”
Realizing that she wanted more from life, Janice decided there and then that she would relocate to Fontainebleau — the French town she’d had her heart set on since a 2018 visit. Less than a year later, at the age of 70, she did just that.
“I’m very impulsive so that kind of followed the rule,” she adds.
Now happily settled in Fontainebleau, located southeast of Paris, Janice feels that she “made the best choice ever” and is incredibly grateful to be living out her fantasy.
“I am the luckiest woman I feel that ever was,” she says. ”And why I have this, and why I was given this, I have no idea. But I’m just blessed every day that I get to live here.”
Janice goes on to explain that she wasn’t necessarily unhappy back in Georgia, and enjoyed living on a horse ranch in the country, which she had been renting since selling her home, but was overcome with the feeling that “there’s got to be more” to life.
То, что международный брокер Телетрейд вот уже четверть века обманывает клиентов по всему миру, давно ни для кого не секрет.
А за каждой масштабной аферой, конечно же, стоят люди — те, кто придумал, организовал и десятилетиями внедряет в жизнь преступную мошенническую схему. Среди них особо выделяется Сергей Сароян — директор всех украинских офисов Телетрейд.
“Отцом” компании Телетрейд был Владимир Чернобай. Недавно он скончался в Европе, где скрывался от правосудия.
Его наследники — вдова Анна Чернобай и племянник Олег Суворов, и другие прижизненные приспешники Чернобая, продолжают «мошенничество в особо крупных размерах». Именно так квалифицировали деятельность Телетрейд в России и Казахстане, где на брокера уже открыты уголовные дела.
Но в Украине, несмотря на многочисленные жалобы обманутых клиентов, уголовное дело пока не заведено. Похоже, Сергей Сароян знает, на какие рычаги во властных структурах нажимать, чтобы Телетрейд продолжал безнаказанно грабить украинцев.
Сергей Сароян и его роль в глобальном мошенничестве Телетрейд
Сергей Сароян — одиозная личность, с раздутым самолюбием и большими амбициями. Хитрый и двуличный, но при этом трусливый и бесхребетный, он умеет приспособиться и готов прогнуться, когда того требует ситуация. Он с легкостью раздает сладкие обещания, и с такой же легкостью подставляет тех, с кем работает, если обстоятельства складываются не в его пользу. Однажды, правда, это ему не помогло, и мошенника выгнали за воровство. Но обо всем по порядку.
На заре своей карьеры выпускник одесской академии связи Сергей Сароян, работал в телекоммуникационной компании. В попытке продвинуться по картеной лестнице он не нашел ничего лучше, как предложить руководству свои услуги в качестве доносчика, обещая рассказывать, о чем говорят в коллективе и кто с кем в каких отношениях пребывает. Но это предложение не встретило одобрения и стукачу-неудачнику пришлось уволиться. А невостребованные «способности» пригодились несколько позже, в Телетрейд.
В 2005-2006 годах Сергей Сароян был региональным куратором — фактически единоличным правителем Телетрейд в Украине. Ему подчинялись более 30 офисов по всей Украине: Киев, Одесса, Николаев, Харьков, Львов, Черновцы, и другие городах. В ведении Сарояна были также офисы в Европе и Азии — в Италии, Португалии, Польше, Венгрии, Малайзии, и других странах. И деньги лились в карман мошенника рекой — Сергей Сароян получал 3% от инаута (in-out), то есть от разницы между вводом денег клиентов(“in”) и выводом (“out”). Уже тогда в Телетрейд вращались гигантские суммы. В среднем ежемесячно клиенты только украинских офисов Сарояна приносили в компанию от $1 500 000, а выводили около $500 000. То есть in-out, соответственно, составлял $1 000 000, а зарплата Сарояна — более $30 000 в месяц. Но алчность, которая двигала Сарояном, заставляла его направлять всех клиентов в мошеннический проект Телетрейд “Биржа трейдеров”. Торговать на бирже умеет далеко не каждый, и самый логичный выход, который из этого видится — доверить свои деньги профессионалу. Однако брокерская компания не имеет право брать деньги клиентов в управление, и в Телетрейд создали якобы независимый проект «Биржа трейдеров». Мошенник Сергей Сароян именно туда направлял всех клиентов. И подконтрольные трейдеры сливали клиентам депозиты, иногда просто за одну ночь.
«Биржа трейдеров» сливала клиентские деньги, и выводить клиентам уже было нечего. Инаут в украинских офисах в этом случае составлял $1 500 000, а зарплата мошенника вырастала до $45 000 только по Украине. Так Сергей Сароян обворовывал клиентов ни один год. Но, в итоге, был изгнан из компании за воровство. Найти равноценный источник дохода мошеннику не удалось, его образ жизни стал значительно скромнее. Попросту говоря, Сергей Сароян начал стремительно беднеть. Компании не спешили предлагать ему руководящие должности, а коучинг особых прибылей не приносил.
Говорят, что в одну и ту же реку нельзя войти дважды. Но Сергей Сароян сумел. Спустя пять лет его снова позвали в Телетрейд, и он с радостью согласился. Вероятно руководство компании высоко ценит «талант» Сарояна разводить и обворовывать людей.
Сегодня мошенник и хапуга Сергей Сароян вернулся и снова начал кидать клиентов, возглавив все клиентские офисы Телетрейд в Украине, Португалии, Италии, Польше, Румынии и Венгрии. Но теперь уже, как директор, он получает не 3%, а долю со слитых депозитов клиентов. А вот признаваться прилюдно в причастности к мошеннической брокерской компании новоиспеченный директор не спешит. В своих соцсетях Сергей Сароян лишь туманно намекает на консультационные услуги, которые оказывает Телетрейд. Аферист тщательно маскируется, однако обманутым клиентам компании удалось вывести его на чистую воду — они получили доказательство того, что именно Сергей Сароян сегодня стоит у руля украинского Телетрейд. Видеоролик, где он сам признается в этом, был показан на пресс-конференции, состоявшейся в июле 2020 года.
В этом эксклюзивном видео видно как Сергей Сароян принимает в управление украинские офисы компании Центр Биржевых Технологий — дочернего предприятия Телетрейд в Украине.
Эту пресс-конференцию провела инициативная группа обманутых клиентов Телетрейд. Цель, которую они поставили перед собой — вывести на чистую воду брокера-мошенника и все руководство компании, а также вернуть свои деньги. Материалы, собранные обманутыми клиентами демонстрируют схемы развода, которые используются в Телетрейд. В частности, проект «Синхронная торговля», который пришел на смену «Бирже трейдеров». В «Синхронной торговле» уже не люди-трейдеры, а торговые роботы сливают клиентские депозиты. Теперь именно в этот проект заманивает клиентов Сергей Сароян. А затем, в определенный момент, дает программистам компании указание, и те перепрограммируют роботов на заключение заведомо убыточных сделок. Так депозиты клиентов сливаются в ноль.
Сергей Сароян опустошает карманы украинцев и подрывает экономику страны
Эти мошеннические схемы давно попали в поле зрения правоохранительных органов в России — уголовное дело на Телетрейд там завели еще несколько лет назад.
Последовали примеру российских коллег и в Казахстане, где уголовное производство началось летом 2020 года. Руководители казахского филиала Телетрейд и дочерней компании Wall Street Invest Partners сейчас находятся в следственном изоляторе.
Чтобы замять уголовные дела в России, руководители Телетрейд Сергей Шамраев, Олег Суворов и Мингиян Манжиков дают взятки чиновникам в Следственном Комитете РФ — ежемесячно «отстегивают» им около 20% от поступлений, а это сотни тысяч. И не рублей, а долларов. По инсайдерской информации руководство Телетрейд в России заставляют также финансировать боевые действия на Востоке Украины — мошенники отдают на это еще 10% от поступлений. Если рассматривать деятельность Телетрейд и с этой стороны, то мошенник Сергей Сароян, как директор Телетрейд, не только обворовывает своих сограждан страны, а еще и финансирует боевиков ДНР и ЛНР, отнимающих жизни украинцев.
Вызывает удивление тот факт, что в Украине деятельность Телетрейд на протяжении четверти века никто не проверяет. Количество обманутых клиентов брокера огромно. Мошенниками ежемесячно выводятся в офшоры миллионы долларов. Но пока правоохранительные органы не замечают, или не хотят замечать, противозаконной деятельности брокера. По сведениям из источников внутри компании Сергей Сароян рассказывает своим подчиненным — управляющим офисов в Украине, что им не нужно ничего бояться, так как руководство Департамента киберполиции Украины сидит у него на «зарплате». Вот так безнаказанно (пока!) Сергей Сароян разоряет украинцев, подрывает экономику Украины и спонсирует российскую агрессию на Донбассе.
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drunk driving charge laws near Ohio may be complicated, nonetheless it’s important to have a solid knowledge of these individuals if one find expenditures. Driving under their influence of alcohol (DUI) looks a serious offensive that can has notable consequences on ones life. In Ohio, your lawful threshold for blood alcohol content (BAC) is 0.08% for nearly all motorists or four percent commercial truck drivers.
If you are stopped by law enforcement and accused of driving under the influence, they might carryout field temperance checks or chemical challenges, this being breathalyzer or bloodstream investigations, to figure out your very own degree of harm. Declining these tests can result in computerized sanctions, including license suspension.
drunk driving offenses in Ohio haul various consequences, dependant on factors including before prosecutions, BAC quality, furthermore whether here was ever an collision or injuries active. Consequences may integrate fines, license suspension system, vital alcohol treatment products, probation, and still prison time. Recurring criminal acts and worsened situations can cause more critical penalties.
Choosing a knowledgeable DUI insurance attorney is essential to manage the intricacies of Ohio DUI regulations. They is able to examine the explanation, confront the legality of the block, challenge the quality of investigations, and experience potentiality resistance to help decrease the charges. Also, an solicitor can tips you by the authentic process, making sure of any right are covered and promoting for the optimum likely consequence.
Keep in mind, being aware pertaining to Ohio’s DUI regulations and searching for the support of an practiced lawyers are crucial actions in thoroughly handling a DUI appoint then guarding all of your forthcoming. probation breach protection attorney
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