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- 00:00In our OpenHPI course, a half-century of internet
- 00:04we up to now considered IP version four.
- 00:09In this clip, we want to have a closer look to inter-networking
- 00:13with IPv6. Let's start
- 00:18IPv4, it was and is very successful.
- 00:23The internet is increasing, it is exploding, and it works fine, and nobody is claiming.
- 00:29But why we need a new internet protocol, why there is a need for change
- 00:36already for a couple of years?
- 00:39So IPv4 currently a is the most popular and the most used IP version.
- 00:46It's extremely successful due to its basic design,
- 00:51the possibility to use IPv4 even with completely new network technologies
- 00:57with completely new hard work technologies, it works fine. So
- 01:02when it was designed a 50 years ago, the
- 01:07kind of computers and networks
- 01:09which are in place today were not even imaginable.
- 01:14So IP version 4 was developed before the spread of the LAN technology.
- 01:22It worked also for networks that are much faster than the one
- 01:29it was originally designed for.
- 01:32It has coped with the enormous growth in the global heterogeneous internet,
- 01:38from a small couple of computers connected in the internet, nowadays
- 01:45to millions of systems which are connected.
- 01:49But besides all this success story,
- 01:55there is an urgent need for a change and there is not only one reason,
- 02:02there is a number of basic problems that cannot
- 02:07be solved with IPv4. The biggest challenge and the
- 02:11biggest problem of IPv4 is the address space.
- 02:16The internet address space is too small.
- 02:19Why it is too small? It was exactly described, an internet
- 02:24address has a length of thirty bits,
- 02:28this cannot be changed. If you change this then the internet
- 02:31protocol needs to be changed. So the 2 bits, it's limited
- 02:37to about 4 billion different addresses.
- 02:41So only four billion different devices can be connected to the internet.
- 02:48Then we run into problems because
- 02:54the system needs to be a unique address,
- 02:56then also systems can send information to here.
- 03:00Here you see 2 curves over the years from the IANA, which
- 03:06is responsible for the internet protocol, which shows that already
- 03:112012-2014 the number of
- 03:16IP addresses was going down a two zero
- 03:23so here you see it more drastically about years where the different
- 03:27a record three s each in each continent of the world has an internet registry
- 03:34so called career a which what happens with the number of available
- 03:40uh uh uh uh ip addresses the real plays a role if you want
- 03:45to connect to the internet you asked an internet service provider
- 03:50to connect you and the internet service providers they need three ip addresses
- 03:55to do this and this free ip addresses they can get from the rise
- 04:01but you see they there were no more free ip addresses available
- 04:08so the last three ip four four address block where allocated by yada
- 04:15two the five regional internet registries already in the year two
- 04:20thousand eleven so the remaining ip addresses are still currently distributed
- 04:27so there exists some companies are buying other companies only
- 04:33to get a access to their IP addresses
- 04:37but more changes are required for IP before
- 04:40the increasing number of internet hosts make routing more and more problematic
- 04:47societies of the routing tables the complexity of the protocol
- 04:52he becomes a two a difficult
- 04:56then also a service type for multimedia data is missing
- 05:02a it cannot be a specified in ip version four and this is a
- 05:07problem because there is no possibility to define quality of service
- 05:12a a parameters for transmission of multimedia data for transmission
- 05:18of synchronous live transmission and other things which are
- 05:23needed for the right presentation
- 05:26there is a lack of support for distributed group work ok cscw
- 05:32computer supported cooperative work a system he provided
- 05:37for that reason a successor for ip before he was needed and indeed
- 05:45already already nineteen ninety five see internet engineering task force
- 05:51this is a responsible for the development of the internet technology
- 05:56started to develop a new ip version which nowadays is called ip six
- 06:04f six adopts working basic concepts of ip v four such as connection less packet service
- 06:12each data gramme of a message is transmitted independently
- 06:16a limited number of a possible hops is this all it was very well
- 06:24he approved with ip four but there were new ideas and new ideas of course
- 06:31c address eyes was poor longer
- 06:35with ip six there are one hundred twenty eight bits
- 06:39a away leper to describe an internet address
- 06:43one hundred twenty eight bits are subdivided in eight a bit groups
- 06:49it's a bit groups are presented in hexadecimal notation with
- 06:54colon as separate and zero compression
- 06:58a p six one of the innovation is a new head of format
- 07:03a new head of ahmed and the usage of multiple head us
- 07:07so there is a mandatory base header but there are optionally
- 07:11one or more additional headers for authentication encryption fragmentation
- 07:17and the idea behind is to give some such information only in case
- 07:23a if for example packages fragmented remember with ip before
- 07:28there was in each header a fragment fields for fragmentation information
- 07:33here the information that's needed in case of fragmentation it's
- 07:38collected in an additional header and this additional header
- 07:43is optionally and is only sent and append to the data packet
- 07:47when the fragmentation is done and then there are different address types
- 07:53for unicast multicast and clusters
- 07:57another area is the support for video and audio transmission
- 08:03so for real time transmission that uh uh uh uh uh uh uh uh
- 08:07uh uh uh uh uh uh uh uh uh uh uh uh uh uh uh uh using mechanisms
- 08:09for determining pre-determined transmission passes to guarantee high quality
- 08:15a transmission of such a continuously data
- 08:20they are more improvements of ip six over ip four
- 08:25the protocol is extendable so new functionalities through additional protocols
- 08:33a for example the mobile ip six now is part of the he is part
- 08:39of the ip six protocol the neighbor discovery protocol
- 08:43based on icmp we six which is replacing the arp protocol a only
- 08:50to give an example there is a host outer configuration mechanisms status
- 08:57dhcp support for mighty homing and renumeration
- 09:02uh it's not so important to understand all this new functionality in
- 09:09he is in the detail if you are interested you can i get a lot
- 09:14more information in our book which is available
- 09:19but a two get in general a impression how what are the difference
- 09:24of ip six to ip four i think this is an app
- 09:29what's important is to have a look to this new addressing scheme
- 09:35because this is the most important design requirement and this
- 09:40was a most important design requirement for the new internet protocol
- 09:46it drastically increase the number of available addresses and
- 09:51this was done to meet the demand particularly in the development
- 09:56of the mobile communication people have
- 10:00almost all people in the world have and a have an a a mobile
- 10:05phone or a smartphone many people have several such devices
- 10:10the other area is the internet of things when although you're
- 10:15smart homes smart traffic smart city then also things can communicate via the internet
- 10:21they need addresses so this was the most important design requirement
- 10:26and the decision was made to have an address length for ip six
- 10:32of one hundred twenty eight bits
- 10:36comparable to ip four there was a thirty two pits
- 10:42so is a space the address space increased from two to thirty two
- 10:48that's about four billion to two to the one hundred twenty eight
- 10:52different addresses which is an unimaginable large a huge number
- 11:00each additional bit from the thirty twos is one hundred and twenty eight
- 11:05doubles the number of possible addresses
- 11:08does not multiplying its doubling its is exponential crows
- 11:13so only to give you an feeling about this number ten hundred twenty three
- 11:19ip addresses could be assigned for each square meter of the earth surface
- 11:26and this is a number that is larger than the age of our world
- 11:34what is the notation for this huge ip addresses for humans
- 11:38is almost impossible to have says a one hundred twenty eight
- 11:42a sequences of a bit
- 11:45so too a to deal with this ip addresses the one hundred twenty
- 11:50eight bits are separated in eight blocks with sixteen bits each
- 11:55and the separate these blocks are separated by columns not
- 12:00by dots like in the case of ip before
- 12:04sixteen blocks are written in hexadecimal notion
- 12:09so as the basic number is not ten like in our decimal system
- 12:13or two like in the burn binary system say he base is sixteen
- 12:19so we have a c c a numbers a one two three four five nine these
- 12:26are ten and then we need six more numbers to describe by one single character
- 12:33so these are the letters a b c d f so the a s c addresses can rewrite
- 12:41right compactly in this exodus l notation with columns system
- 12:49there is another idea to shorten see address and this is ok zero compression
- 12:56and the idea is the following first suppression of all the leading series
- 13:02so if it's a the number ten in the sixteen block there are
- 13:07many series before they can be done
- 13:10then summary of a block sequence of cyrus as empty character
- 13:17so if there is a block consisting only of zeros
- 13:21then it is omitted completely we can recognises in the situation
- 13:28that there are two colons close to each other
- 13:32let's consider an example this is such an ip six address here
- 13:36you see there also let us up to f a inside says
- 13:43and they are our leading zeros the first step is to omit the
- 13:47leading cirrus so here we can a a takes a three series away here one
- 13:55uh uh uh uh here one and here too and then we have the situation
- 14:02that we have zero a that we have three candidates consisting only from service
- 14:08these are three office is equal says and then there is the next step
- 14:14said we comprises and we can recognise here that we can do this one times
- 14:20you can recognises that there are two columns aside
- 14:24and reconstructing the original ip six address is easy
- 14:29because it's exactly clear we have eight blocks
- 14:33and here are only one two three four five blocks three blocks are missing
- 14:39and the missing blocks are consequently if zero a blocks
- 14:43so in this way one can manage to a notate the ip addresses
- 14:49in a quite compact form
- 14:53yeah when i introduced ip six i already mentioned that there are different
- 14:57ip address components
- 15:00so the ip six address architecture consists of three components
- 15:06there is a prefix the subnet idea and the interface idea
- 15:11these are the three components of c a of c ip six address the prefix
- 15:17it's also called a side idea describes the type of ip address
- 15:22or indicates the location for example is the sp or the company
- 15:27to which the address is belonging
- 15:30then in the middle we have a subnet idea
- 15:33subnet id describes the private topology for example within a private network
- 15:39and then we have the interface idea set standards for the internet
- 15:44for the network interface and can be calculated from the mac address
- 15:50as an example the mac address this wall's address of a computer inside a network
- 15:56inside the network technology for example inside is on it and
- 16:01from that the ip address at least a part of the ip address
- 16:05can be a computed this is the idea here of ip six
- 16:12if we look to the data packet also the data packet a differs from a that
- 16:18of ip we from as a problem with a packet in a with the data
- 16:23a with a data packet format in ip four wars that many ip
- 16:30b four header fields are left empty or are not relevant for a concrete transmission
- 16:37so it's a waste of space it increase route allowed its increased
- 16:43traffic inside the network
- 16:45so the improvement for a pv six wars that one is not working with one hara
- 16:52there is an optional use of several small headers adopted to the respective
- 16:58uh situation so here we have a a mandatory a mandatory header
- 17:06the base had a you remember it's double in size of a ip v four header
- 17:13although the ip addresses which is an important information inside the header
- 17:21is he much larger it's a four times a larger send the addresses in IP
- 17:29before and then there could be a sequence of additional headers.
- 17:35For example header style something about the fragmentation and another header
- 17:39that it held something about the encryption and then we have the payload
- 17:45and in a data IPv6 data package inside of 8 bytes 264Kb.
- 17:54This gives you an impression of this new internet protocol design
- 18:01it has needed a long time that IPv6 to come into practice. Many people
- 18:08were thinking oh my system works with IPv4, do not touch
- 18:12it otherwise we get problems. Meanwhile, we have to do and so today
- 18:17it's about 15 to 20 percent of the internet traffic
- 18:21which is realized with IPv6.
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Explanation:
- 10:10: To illustrate the incredibly large number: 2^128 IP addresses would make 10^23 (100 000 000 000 000 000 000 000) IP addresses per square meter of the earth's surface.