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What I'd like to point out once again is that each web site is resolved to a different IP address.
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Lastly if I ping CNN.com notice that that also resolves to an IP address but it's different to the previous
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examples.
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DNS is doing the name resolution so it's resolving a domain name to an IP address and that's how I'm
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learning the IP address of CNN dot com or Google dot com.
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You can ping many of the well-known Web sites on the internet to find out what the IP addresses are.
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You could also use this look up which just does a DNS resolution of a domain name rather than trying
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to pin the server.
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So in summary the devices on the Internet have been configured with IP version 4 addresses.
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I'll explain more about the formatting of IP addresses in the next few minutes.
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But for now just take note that every device has an IP address and that includes my own machine or the
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command IP config will show me the IP address on my local machine.
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When using Windows.
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So in this example my IP version 4 address is 10.0 0.6.
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You'll also notice here that I have an IP version 6 address of 2001 Colin 20 colon colon.
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In this video we are concentrating on IP version for addresses but in another video I'll explain IP
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version 6 IP version 6 is becoming more and more important because IP addresses are now exhausted in
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certain parts of the world IP version 4 or Internet Protocol version 4 is a layer 3 or network a layer
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protocol as per the OS model.
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You know different video.
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I explained the OS on model.
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So if you're not sure about layers Please refer to that video IP version 4 is a connection list protocol.
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In other words there are no sessions formed when traffic is transmitted.
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The transmitter simply sends data without notification to the receiver.
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No status information is sent back from the receiver to the transmitter.
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It's totally connection less TZP for transmission control protocol.
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On the other hand is connection orientated TZP will set up a session.
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So before transmission takes place in TZP the transmitter sends what's called a sun or synchronization
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message to the receiver.
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There's a sim ack message from the receiver to the transmitter and then a ack or acknowledgement message
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from the transmitted to the receiver.
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So before any data is transmitted but devices using TZP go through what's called the three way handshake.
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Some send ack and ack IP on the other hand doesn't do any of that.
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Each packet is treated independently of other packets.
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That's why traffic can take different paths to get to a destination.
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Rodders will route the traffic via different paths based on options such as load balancing because each
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packet is independent.
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An IP is a connection list protocol.
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Routers can also base routing decisions on different values such as bandwidth or hop count.
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But it is possible that packets from one session take divergent or different parts to get to a destination.
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So for example Ripp will base its routing decisions on hop count which is not good and hence Repp is
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not used that often anymore.
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OSPF will base it on bandwidths other running protocols will use their own metrics to determine the
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best path.
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I'll be discussing routing protocols in more detail later in this course but in brief writing protocols
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determine the best path or best route from A to B.
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This is based on the whole Rockhill addressing structure in IP version for an IP version 6 where we
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have both a network and host portion as part of the address Rawdon's base their routing decisions on
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the network portion of the address rather than on the host portion of the address and I'll explain network
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and host portions in a moment.
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IP also only gives best effort to delivery of packets.
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There is no guarantee of packet delivery any packet could be misdirected.
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It could be duplicated or it could be lost in transmission when sent to a destination and that should
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be expected in IP transmissions.
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Once again TZP which is a connection oriented protocol has the ability to read transmit packets that
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go missing UDP another layer for protocol doesn't retransmit packets.
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If they get dropped simply lost and the applications need to take care of that.
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There is also no data recovery features in IP.
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If the packet for example gets corrupted the end devices need to handle that and not the routers in
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between.
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So in summary IP has no boltin sessions no data recovery no retransmissions Hialeah protocols such as
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TCAP will need to handle dropped packets corrupted packets misdirected packets and so forth.
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IP does not provide those features and relies on Hialeah protocols to implement those features.
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So let's look at the format of an IP version for address an IP version for address is 32 bits in size
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normally written in dotted decimal notation such as this example 10 dot one dot 1.1 each of value such
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as 10 is 8 bits in size.
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So in other words we have x x x done X with each X being 8 bits in length.
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Also known as an octet the total size of the address is 32 bits.
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Please refer to the binary video.
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If you're not sure about bits and how to convert this address into binary and back again IP addresses
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once again have a rock hill structure to enable routing which consists of two main parts.
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We have the network portion of an address and the host portion and we look at that in more detail in
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a moment.
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IP addresses are used for routing in a very similar way to the way DHL or FedEx ranked parcels based
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on a destination address route as will route traffic to a destination address.
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When unicast packets are transmitted multi-course packets use a different mechanism and do a routing
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based on source address.
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So as an analogy DHL or FedEx are sending the possible to a destination based on the destination on
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the parcel routers are sending packets to destinations based on the destination address in the packet.
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